-
Antibiotic Dynamics
Bact growth inhibited by antibiotic [] above MIC
MIC of antibiotic can vary 100-fold depending on bact species - higher MIC = greater likelihood of resistance.
-
Antibiotic Dynamic - 1st Gen Cephalosporins: Cefazolin
EXAMPLE
- Resistance breakpoint >8 mg/L
- MIC of E coli (8) > S. aureus (1) > S. pyogenes (0.1)
Can use cefazolin for E. coli UTIs because of high concentration in urine, but NOT systemically
-
Empiric Therapy
No gram stain or culture taken
- Best guess therapy - antibiotic choice depends on:
- Infection
- Most likely organisms
- Resistance patterns
- Severity
- Location
- Immune Status
- USE MORE BROAD SPECTRUM
- Greater chance of failure/adverse events
-
Targeted Therapy
Identify organisms by gram stain or culture
-
Case 1: Strep Throat
Tx for Group A Strep Pharyngitis Tx
- Oral: Penicillin V x 10 days
- Amoxicillin 50mg/kg/day x 10 days
- (DEPENDENT ON AGE + WEIGHT)
IM: Benzathine Penicillin G x 1 dose
- If penicillin allergy: azithromycin, clarithromycin, clindamycin
- OR
- Oral 1st gen cephalosporin x 10 days if no hx of IgE mediated rxn
-
Penicillin Allergy - Cause, Alternate Agents, Different Reactions, Desensitization
Rxn to b-lactam ring structure
Use aztreonam or any non b-lactam antibiotic for ANAPHYLACTIC rxn
Must differentiate between immediate-onset IgE or delayed onset (rash): use penicillin skin test to differentiate
Cephalosporins OK as long as not IgE rxn
If penicillin absolutely necessary (syphilis), can desensitize with increasing amounts of antibiotic in hospital
-
Case 2: Abrasion at softball tournament
Leg is painful, tight
Non-purulent cellulitis: Strep A/B or MSSA
- Mild to moderate inf:
- Oral therapy: dicloxacillin or cephalexin
If significant penicillin allergy: oral macrolide (azithromycin) or clindamycin
- Severe infection: IV nafcillin or cefazolin
- If severe allergy: vancomycin
-
Case 3: 5 days after Case 2 tx, cellulitis worsened, purulent discharge occurring: MRSA
MRSA: mecA gene codes for new PBP2a, MRSA resistant to ALL b-lactams
-
CA-MRSA
If cultured in outpatient or in hopsital setting less than 72 hrs post-admittance
Incision and Drainage (I&D) tx of choice for ISOLATED cutaneous abcess
- If severe disease, rapid progression, co-morbidities:
- Oral antibiotics for mild-moderate:
- Clindamycin
- Doxycycline
- TMP-SMX (bactrim)
- Linezolid
Children: topical mupirocin for impetigo from CA-MRSA OR oral clindamycin
-
HA-MRSA
Usually MDR
IV Vancomycin (MIC slowly creeping up, fear of VRSA/VISA)
Alternative Agents:DaptomycinLinezolidMupirocin ointment (bactroban)
-
Case 4: 36 y/o HIV+ IV drug user
Infective endocarditis
All for at least 4, some as long as 6 weeks of tx
- Depends on organism
- Viridans Strep (low MIC): Penicillin G or ceftriaxone
Viridans Strep (high MIC): Penicillin G OR ceftriaxone + high-dose gentamicin
Viridans Strep (very high MIC): Vancomycin + low-dose gentamicin
MSSA: Nafcillin +/- low-dose gentamicin
MRSA: Vancomycin
Enterococcus (ampicillin sens): Ampicillin + low-dose gentamicin
Enterococcus (ampicillin res): Vancomycin + low-dose gentamicin
-
Case 5: Acute Otitis Media (AOM)
Usually Strep pneumo, H. flu or Moraxella catarrhalis
Tx: amoxicillin +/- clauvanate (augmentin) at twice-normal doses for potential penicillin resistant strains
-
AOM: New guidelines (2013)
Severe AOM: antibiotic therapy in children 6 months and older
Non severe bilateral AOM: antibiotic therapy in 6-23 months
Non-severe unilateral AOM: antibiotic therapy OR observation and close follow up in ALL children
Antibiotic of choice: high dose amoxicillin IF patient has not received amoxicillin within previous 30 days OR does not have concurrent purulent conjunctivitis
NO ANTIBIOTIC IF OLDER THAN 2 Y/O
-
Rhinosinusitis: Adults
5th most common diagnosisn for which antibiotics are prescribed
Antibiotics NOT recommended for initial tx of sinusitis in adults: Use OTC for pain, fever, cough, nasal congestion
Bact infection more likely if symptoms > 7 days, with maxillary pain/purulent discharge
-
Rhinosinusitis: Children
Antibiotics recommended for acute bact sinusitis: usually strep pneumo, h flu or moraxella catarrhalis
Use same antibiotics as for AOM:
Double dose of amoxicillin or augmentin
-
Case 6: 72 y/o woman, flu like symptoms:
CA-Pneumonia--Causative organisms
- 43% Strep pneumo
- 29% Mycoplasma pneumo
- 18% Chlamydolpha pneumo
- 16% Legionella pneumo
- 11% resp viruses
- 6% H flu
- 1-5% S. aureus
-
Drug Resistanst Strep Pneumo (DRSP):
Risk Factors
43% incidence of DRSP at Sentara
- Risk Factors: B-lactam therapy within prev. 3 months
- Age <2 or >65
- Alcoholism
- Co-morbidities: heart, lung, liver, renal disease
- Diabetes
- Immunosuppressive illness/therapy
- Exposure to child in day care center
-
Outpatient Tx of CA-Pneumonia
Cover for S. pnuemo and atypical
Azithromycin (1st choice) or doxycycline (2nd choice) - if previously healthy, no risk factors for DRSP
Resp fluoroquinolones (levofloxacin or moxifloxacin) if comorbidities or other risks for DRSP
- High dose amoxicillin-clauvante + macrolide:
- If co-morbidities AND other risks for DRSP
- Can sub 2nd gen cephalosporin for amoxicillin
-
Antibiotics for DRSP
- Intermed penicillin resistance:
- High dose amoxicillin or amox-clauvanate
- Resp. fluoroquinolone
- Ceftriaxone or cefotaxime for meningitis
- High penicillin resistance:
- Ceftriaxone or cefotaxime
- Resp fluoroquinolone
- Vancomycin and rifampin for meningitis
-
Antiarrhythmics: Classifications
By electrophysiological effects on usually normal cardiac cells (traditional approach): Vaughn-Williams classification
- By type of arrhythmia (fairly new but more common sense approach):
- Supraventricular arrhythmias
- Ventricular arrhythmias
-
Cardiac Conduction Cycle (5 phases of Action Potential)
Phase 0: Vent depol (QRS) due to Na+ entry into cell via fast sodium channels
Phase 1: overshoot phase due to Ca2+ entering cell and contraction
Phase 2: plateau phase with balance between inward currents through slow Na+ and Ca2+ channels and OUTWARD K+ current
Phase 3: repolarization (T wave) due to outward K+ current
Phase 4: Na+ moves out of cell and K+ into cell via active pump
-
Anti-arrhythmic Agents:
Vaughn-Williams Classifications
Class I: block SODIUM channels -> slower depolarization
- 1a: intermediate block duration (also reduce K+ current)
- 1b: rapid block duration (only ischemic cells)
- 1c: long block duration
Class II: block B1 receptors in AV node
Class III: block POTASSIUM channels -> prolonged QT interval (most-used currently)
Class IV: block L-type Ca2+ channels in AV node
-
Anti-arrhythmic Agents
Class I
Block sodium channels -> slower depol
- 1a - intermediate block duration (also reduce K current):
- Quinidine
- procainamide
- disopyramide
- 1b - rapid block duration (only in ischemic cells):
- lidocaine (only in cardiac arrest)
- mexiletine
- 1c - long block duration: A-fib
- flecainide
- propafenone
Class I can induce own arrhythmias
-
Anti-arrhythmic agents
Class II
- Block B1 receptors in AV node:
- B-blockers
-
Anti-arrhythmic agents
Class III
- Block potassium channels resulting in prolonged action potential duration (prolonged QT interval):
- ibutilide
- dofetilide
- Mixed Class III:
- amiodoraone
- sotalol
- Increases risk of Torsades de Pointe, sudden death
- Most used currently
- Mixed Class III agents also have minor class I and II properties
-
Anti-arrhythmic agents
Class IV
- Block L-type calcium channels in AV node:
- verapamil
- diltiazem
-
Indications for Anti-arrhythmic Agents
- Supraventricular:
- Ia
- Ic
- II slows ventricular response
- III
- IV slows ventricular response
- Ventricular:
- Ia
- Ib
- Ic
- II slows ventricular response
- III
- IV slows ventricular response
-
Supraventricular arrhythmias
Sinus bradycardia
Sinus tachycardia
- Paroxysmal supraventricular tachy:
- Adenosine, class IV agents
Atrial flutter
- Atrial fibrillation:
- Class Ic, II, III, and IV agents and digoxin
- Wolf-Parkinson-White Syndrome:
- Class Ia and Ic agents
Premature atrial contractions (PACs)
-
Ventricular arrhythmias
- Premature ventricular complexes (PVCs):
- Class II agents, amiodoraone
- Non-sustained ventricular tachy:
- Class II agents
- Sustained ventricular tachy:
- IV amiodarone, sotalol, procainamide
- Ventricular fibrillation:
- IV amiodarone or lidocaine after defibrillating shock
-
Classification of Atrial Fibrillation
Look at chart on slide 12
-
Management of A-fib
- Ventricular Rate Control:
- Drug therapy, AV node catheter ablation
- OR
- Conversion to and maintenance of normal sinus rhythm:
- No tx
- Drug therapy
- Ablation or pacemake
- PLUS
- Prevention of thromboembolism
-
AFFIRM Study: indications for best management of Afib
Rate control preferred over rhythm control - fewer adverse events
-
A-fib: Agents for rate control
- B-Blockers (Class II): considered slightly safer than others
- Esmolol (IV) - in hospital, fast-acting
- Propanolol
- Metoprolol
- Non-DHP Ca-channel blockers (Class IV):
- Diltiazem
- Verapamil
Digoxin
-
B-Blockers: Class II Anti-Arrhythmic Agents
- Esmolol (IV only), half life 9 min.
- Propanolol (IV + PO)
- Metoprolol (IV + PO)
- Most effective drug class for rate control in Afib
- Decreased AV node conduction and slow AV node refractory period
- Rapid onset IV
- Esp useful with high adrenergic tone (hyperthyroidism/post-op)
- Can use digoxin for synergy (monitor heart rate, BP)
- Caution: use in asthma, untreated heart failure, COPD
-
B-blockers: Indications
Esp. Useful with high adrenergic tone (hyperthyroidism/post-op)
A-fib, FIRST LINE
-
B-Blockers: Mech of Action
Decreased AV node conduction, slow AV node refrac period
-
Calcium Channel Blockers: Class IV Anti-arrhythmic Agents
- Verapamil - IV + PO
- Diltiazem - IV + PO
- Only NON-DHP CCBs have antiarrhythmic activity
- Decrease AV node conduction, slow AV node refrac period by blocking Ca channels in AV node
- Rapid onset IV
- More likely to cause hypotension than B-blockers
- -------------------------------
- Drug Interactions:
- Increase digoxin concentrations
- Potent inhibitors of CYP 3A4
- Monitor: HR, BP
- Avoid use in heart failure: negative inotropic effect
- Contraindicated in Wolf-Parkinson-White Syndrome (WPW): may accelerate conduction down accessory pathway and cause V-tachy
-
NON DHP CCBs: Indications
A-fib
-
NON DHP CCBs: Mech of Action
Decrease AV node conduction, slow AV node refrac period by blocking Ca channels in AV node
-
Digoxin
- Digitalis glycoside primarily used in HF - positive inotropic agent
- Narrow therapeutic index drug - req periodic plasma drug level monitoring
- No longer first line therapy for rate control of A-fib
May be used if patient in heart failure or has LV dysfunction
- Slow onset, less effective than B-blockers or CCBs
- A-Fib caused by high adrenergic tone is often digoxin resistant
- Not effective in controlling rate during exercise
- Proarrhythmic with high doses: causes AV block and V-tachy
- Drug interaction with Non-DHP CCBs -> higher plasma levels, but can be used for synergy
Contraindicated in WPW syndrome like CCBs
Monitor: digoxin levels, HR, EKG
-
Digoxin: Indications
- Heart failure - positive inotropic agent
- Second line/synergistic for A-fib
-
Digoxin: Mech of Action
Digitalis glycoside
-
A-fib: Rate control drugs
- B-blockers:
- Esmolol
- Propanolol
- Metoprolol
- Ca-Channel Blockers (NON DHP ONLY):
- Diltiazem
- Verapamil
Digoxin
-
A-Fib: Sinus Rhythm Control Agents
- Class III:
- Block potassium rectifier channels responsible for repolarizing myocardial tissue during phase 3 of AP
- Prolong ventricular repolarization
- Prolong QT interval on EKG (QTc refers to QT interval corrected for heart rate)
- Mixed Class III:Amidoranone, Dronedarone, Sotalol
- Class III: Dofetilide, Ibutilide
- -----------------------------------
- Class Ic:
- Bind sodium channels when in open/inactivated state, dissociate during resting state
- Very slow rate of dissociation (different from class Ia/Ib)
Greater effect on conduction rate throughout heart, esp His-Purkinje system
Flecainide, Propafenone
-
Amiodarone
- Red Flag Drug
- Mixed Class III anti-arrhythmic drug
- Blocks potassium currents during Phase 3 of AP, also blocks sodium and calcium channels, B-receptors
- Causes prolongation of PR, QRS, QT interval
Considered first-line agent for most cases of AF requiring rhythm control
Anti-arrhythmic agent of choice in heart failure
More effective than Sotalol or Class Ic agents in preventing recurrence of A-Fib
Therapy complicated by adverse effect and drug interaction profile
-
Amiodarone: Mech of Action
Blocks potassium currents during Phase 3 of AP, also blocks sodium and calcium channels, B-receptors
-
Amiodarone: Indications
- Considered first-line agent for most cases of AF requiring rhythm control
- Anti-arrhythmic agent of choice in heart failure
- FDA Approved: Sustained V-tachy, V-fib
- Off-label: Maintenance of sinus rhythm in A-Fib
-
Amiodarone: Adverse Effects
Long T 1/2 - may take one year to eliminate drug, stop adverse effect
- Pulmonary toxicity
- Hypo/Hyper-thyroidism
- Liver Toxicity
- GI effects
- Ocular effects
- Dermatologic effects
- Neurologic toxicity
- Cardiovasular effects: bradycardia, heart block, QT prolongation, Torsades de Pointes (1%)
-
Amiodarone: Drug Interactions
Inhibits CYP 1A2, 2C9, 2D6, 3A4
- Must decrease Warfarin dose
- Doubles Digoxin levels
- B-blockers - bradycardia, heart block
- CCBs - bradycardia, heart block
- Anti-arrhythmic drugs - increased serum levels of quinidine, disopyramide, flecainide, propadenone, dofetilide
- Additive with drugs that lengthen QT interval
-
Amiodarone: Dose
- Loading dose of 800mg/day until 10gm reached
- Maintenance dose of 200-400mg/day for V-arrhythmias and 200 mg/day for A-fib
-
Amiodarone: Monitoring
Need extensive baseline assessment, freq monitoring during outpatient loading dose period, evaluations every 6 months
-
Dronedarone
- Mixed Class III - structurally related to amiodarone
- Indicated for prevention of hospitalization in patients with a-fib or a-flutterDoes not contain iodine (amiodarone contains iodine, causes adverse thyroid rxns)
- Considerably shorter half-life (1 day vs 50 for amiodarone)
- No loading dose req
- Contraindicated in HF with EF < 35%
-
Dronedarone: Indications
Prevention of hospitalization in patients with a-fib or a-flutter
-
Dronedarone vs Amiodarone
Dronedarone doubling of death rate compared to amiodarone in patients with Class II/IV heart failure
Dronedarone less effective in maintaining sinus rhythm but better safety profile
-
Sotalol
- Mixed Class III
- Non selective B-blocker - also blocks potassium rectifier currents, prolongs QT interval
- Uses: maintenance of sinus rhythm in A-fib, suppression of other supraventricular tachys
- Kinetics: Oral only, renal elimination unchanged
- Adverse Effects:
- Dose related QT interval prolongation
- Proarrhythmias at higher doses (torsades - higher than amiodarone)
- Bradycardia
- Exacerbation of asthma or COPD
- Dosing:Slow titration of dose with QTc interval monitored 2-4 hrs after each dose change
- Contraindication: CrCl < 40mL/min
- Monitoring: EKG monitored for 3 days in hospital when starting therapy
-
Sotalol: Mech of Action
Non-selective B-blocker, also blocks potassium rectifier currents, prolongs QT interval
-
Sotalol: Uses
- Maintenance of sinus rhythm in a-fib
- Suppressin of other supraventricular tachys
-
Sotalol: Adverse Effects
- Dose related QT interval prolongation
- Proarrhythmias at higher doses: incidence of Torsades higher than amiodarone
- Bradycardia
- Exacerbation of asthma or COPD
-
Dofetilide (Tikosyn)
- Class III agent
- Prolongs QT interval and ventricular repolarization
- Uses: ONLY class III agent for both conversion and maintenance of sinus rhythm in AF
- Education program mandatory
- Oral Only
- Adverse: Dose related QT interval prolongation
- Torsade de pointes in 3% of patients
- Drug Interactions: Drugs also prolonging QT interval contraindicated
- Use caution with drugs depleting potassium (diuretics) or Mg, also with CYP 3A4 inhibitors
- Dosing: Reduce dose if CrCl < 60mL/min
- Monitoring: EKG monitoring over first 3 days in hospital
-
Dofetilide (Tikosyn): Mech of action
Prolongs QT interval and ventricular repolarization
-
Dofetilide (Tikosyn): Adverse Effects
- Dose related QT interval prolongation
- Torsade de Pointes in 3% of patients
-
Ibutilide
- Class III agent
- IV use only
- Indication: conversion of a-flutter or a-fib to normal sinus rhythm
- Precautions: prolongs QT interval
- EKG monitoring for 4 hrs post-infusion
-
Flecainide (Tambocor)
- Class Ic
- Prolongs PR and QRS intervals
- Uses: conversion and maintenance of sinus rhythm in AF, suppression of other supraventricular tachys
- Adverse Effects: may increase ventricular rate
- Dizziness, visual disturbances, dyspnea, hadache, fatigue, tremor, nausea
- Drug Interactions: Inhibitors of CYP 2D6, drugs with negative inotropic effects, alkalinizing agents may increase serum levels
- Pill in the Pocket Dose: 300mg x 1 dose after onset of palpitations as outpatient
Avoid if coronary artery disease, structural heart disease, or heart failure - potent negative inotropic effects
Monitoring: EKG, pulse, BP, serum levels
-
Flecainide: Mech of Action
Prolongs PR and QRS intervals
-
Flecainide: Adverse Effects
- May increase ventricular rate
- Dizziness, visual disturbances, dyspnea, headache, fatigue, tremor, nausea
-
Flecainide: Indications
- Conversion and maintenance of sinus rhythm in AF
- Suppression of other supraventricular tachys
-
Flecainide: Pill in the Pocket Dose
300mg x 1 dose after onset of palpitations as outpatient
-
Flecainide: Contraindications
- Avoid if:
- Coronary artery disease
- Structural heart disease
- Heart failure
Drug has potent negative inotropic effects
-
Propafenone
- Class Ic
- Prolongs PR and QRS intervals - some nonselective B-blocking properties
Uses: conversion and maintenance of sinus rhythm in AF, suppression of other supraventricular tachys
Kinetics: Oral only, NONLINEAR KINETICS - serum levels may increase tenfold as dose is slowly increased
Adverse Effects: Bradycardia, heart failure, nausea, taste disturbances, dizziness, fatigue, bronchospasm, constipation
Drug Interactions: Inhibits CYP 2D6
Pill-in-the-Pocket Dose: 600mg x 1 dose after onset of palpitations as outpatient
Same precautions and contraindications as flecainide
Monitoring: EKG, pulse, BP
-
Propafenone: Mech Of Action
Prolongs PR and QRS intervals, also some nonselective B-blocking properties
-
Propafenone: Uses
Conversion and maintenance of sinus rhythm in AF, suppression of other supraventricular tachys
-
Propafenone: Kinetics
Nonlinear kinetics
-
Propafenone: Adverse Effects
- Bradycardia
- Heart Block
- Heart failure
- Nausea
- Taste disturbances
- Dizziness
- Fatigue
- Bronchospasm
- Constipation
-
Propafenone: Pill in the Pocket Dose
600mg x 1 dose for palpitations in outpatient
-
Propafenone: Contraindications
- Avoid if:
- Coronary artery disease
- Structural heart disease
- Heart failure
Drug has potent negative inotropic effects
-
Pill-In-The-Pocket Dose
Flecainide, Propafenone
-
Rate vs. Rhythm Control
Rate control first
- Rhythm control if:
- persistently symptomatic w rate control
- Rate control not maintained
- heart failure
-
CHADS2
- Congestive heart failure - 1
- Hypertension - 1
- Age > 75 - 1
- Diabetes - 1
- Prior stroke or TIA - 2
-
Warfarin Alternatives for Stroke Prevention in A-Fib
Clopidogrel + aspirin - intermediate results between aspirin and warfarin
Dabigatran - twice daily, non-inferior
Rivaroxiban - once daily, non-inferior
Apixaban - twice daily, non-inferior
-
Supraventricular Tachycardias (Normal QRS)
- Sinus bradycardia
- Sinus tachycardia
- Paroxysmal supraventricular tachy (PST)
- Atrial flutter
- Atrial fibrillation
- Wolf-Parkinson-White (WPW) syndrome
- Premature atrial contractions
-
Adenosine
Uses: acute paroxysmal supraventricular tachy (PST)
Ultrashort acting IV agent - T1/2 = 9 seconds
Opens potassium channels in AV nodal cells -> hyperpolarization
Low toxicity profile
Reduces conductance along slow anterograde pathway
-
Adenosine: Mech of Action
Blocks conduction in AV node
Opens potassium channels in AV nodal cells resulting in hyperpolarization
-
Ventricular Arrhythmias
Non-pharma therapy predominates
Premature Ventricular Complexes: Class II agents, amiodarone
Non-sustained ventricular tachycardia: Class II agents
Sustained ventricular tachycardia: IV amidoarone, sotalol, procainamide
Ventricular fibrillation: IV amiodarone, or lidocaine after defibrillating shock
DRUGS ARE SECOND CHOICE
-
Class Ia and Ib Antiarrhythmic Agents
Now used infrequently
- Ia:
- Block both fast sodium channels and potassium channels
- Decrease ventricular conduction velocity and prolong action potential
- Some anticholinergic effects on SA/AV nodes
- Quinidine, porcainamide, disopyramide
- Ib:
- More pronounced effect on ischmic tissue
Lidocaine, mexiletine, tocainide
-
Quinidine
- IV for malaria
- D-isomer of quinine
- Adverse: diarrhea, torsade de pointes, cinchonism
= Class Ia anti-arrhythmic
-
Procainamide
Converted to active metabolite in liver
Adverse: can cause drug-induced lupus with positive ANA titers after chronic use, hypotension, torsade
= Class Ia anti-arrhythmic
-
Dyspyramide
Greater neg inotropic and anticholinergic effects that quinidine or procainamide
Adverse: urinary retention, blurred vision, torsades
= Class Ia anti-arrhythmic
-
Lidocaine
- Class Ib
- Only IV for Ventric arrhythmias
Local Anesthetic
CNS toxicity with higher serum levels - alternative to amiodarone for pharmacologic treatment of v-fib
-
Mexiletine
Oral congener of lidocaine
nausea, tremor common
-
Drug-Induced Arrhythmias
Sympathomimetic Drugs: Increase automaticity of SA node, AV node, Purkinje fibers
- Digoxin: Heart block, Ventric-tachyarrhythmias
- Use digoxin-immune Fab (Digibind) as primary antidote
TORSADE DE POINTES
-
Torsade de Pointes
Secondary to anti-arrhythmic, other drugs
Extension of QT interval
Polymorphic ventricular-tachy
Eventually leads to v-fib, sudden death
-
Drugs removed from market for Torsades
- Terfenadine (Seldane)
- Astemizole
- Cisapride
- Grepafloxacin
-
Torsades - Risk Factors
Using drugs, esp in combination, known to prolong QT interval
Drugs that inhibit CYP enzymes responsible for metab of QT prolonging drugs
- Advanced age
- Hypokalemia
- hypomagnesemia
- Bradycardia
- Coronary artery disease
- LV hypertrophy, dysfunction
-
Prevention of Torsades
- EKG at baseling, regular intervals after
- Avoid drugs if baseline QTc > 440msec
- Reduce dose or discontinue drug if QTc > 500msec on therapy
- Monitor electrolytes
-
Drugs Causing Prolonged QT interval or TdP
- Class Ia
- Class III
- Azole antifungals
- Fluoroquinolones
- Macrolides
- Tricyclic antidepressants
- Typical/atypical antipsychotics
- Droperidol
- Indapamide
- Methadone
- Ranolazine
- Tamoxifen
- TMP-SMX
-
Tx of TB: Goals & organization/supervision
- Goals:cure patient
- minimize transmission to M. tuberculosis
- -------------------------------------------------
- Organization & supervision of Tx:
- tailored to patient clinical & social circumstances
- emphasis on directly observed therapy (DOT) to ensure adherence
-
TB screening
- Mantoux Tuberculin Skin Test = standard
- uses tuberculin purified protein derivative (PPD) (w/ 5 tuberculin units in injection)
- pos PPD does NOT distinguish btw latent and active infection
-
Isoniazid (INH)
- = derivative of nicotinic acid
- -------------------------------------------
- MOA:
- inhibit synthesis of mycolic acid, necessary for cell wall structure
- ------------------------------------------
- Use: drug of choice for latent TB infection (LTBI)
- combo TX for active infection
- -------------------------------------------
- Adverse Effects:inc liver enzymes
- hepatitis (rare)
- peripheral neuropathy (esp in slow acetylators), caused by B6 deficiency (need to supplement)
- ----------------------------------------------
- Drug interactions:
- inhibit CYP 2C9 & 2C19
- inc serum warfarin, phenytoin, benzodiazapenes
- -------------------------------------------
- Monitoring:
- periodic measurement of serum transaminase levels (w/ LFT)
-
Acetylation of INH
- ~50% of US pop = slow acetylators of INH
- = AR
-
Rifampin
- MOA: inhibits bacterial RNA polymerase
- --------------------------------------------------
- Uses:alternative single agent for LTBI (2nd choice)
- combo therapy for active TB infeciton
- never used as single agent for active infection --> res
- ---------------------------------------------
- Adverse Effects:
- flu-like illness (</= 5%)
- potential hepatic toxicity (esp with alcohol use)
- reddish orange color of urine, tears, saliva, contact lens (body fluids)
- -----------------------------------------------
- Drug interactions:potent inducer of CYP 450 enzymes
- inc metabolism of many drugs, incld many for HIV
- biggest drawback of rifampin
- -------------------------------------------------
- Monitoring:liver function tests (LFT)
-
Newer Rifampins
- derivatives of rifampin w/ similar MOA & adverse effects
- ------------------------------------------------
- Drugs:
- Rifabutin
- Rifapentine
-
Rifabutin
- derivative of rifampin w/ similar MOA & adverse effects
- ------------------------------------------------
- least potent inducer of CYP 450 enzymes of the different rifampins
- preferably used in HIV pt
-
Rifapentine
- derivative of rifampin w/ similar MOA & adverse effects
- ----------------------------------------------------
- intermediate between rifampin & rifabutin in drug interaction potential (bc of effects on CYP 450)
- can be given 1x week in select pt (vs 1x day, others)
-
Pyrazinamide
- MOA: exact mech unknown
- ----------------------------------------------------
- Use:combo therapy for active TB infections allows reduction in tx duration
- ------------------------------------------------
- Adverse Effects:hepatotoxicity, esp in combo w/ rifampin
- hyperuricemia & gout
- -------------------------------------------------
- Drug Interactions:blocks hypouricemic action of allopurinol
- ----------------------------------------------
- Monitoring:LFT, uric acid
-
Ethambutol
- MOA: impairs bacterial metabolism
- --------------------------------------------------
- Use:Combo therapy for active TB infection
- --------------------------------------------
- Adverse Effects:optic neuritis @ higher doses
- red-green color blindness
- ---------------------------------------------
- Drug interactions: none
- -------------------------------------------
- Monitoring:visual acuity tests before tx and every month
-
Recommended Tx for Latent TB infection (LTBI)
- > First line therapy:
- Isoniazid (INH) (1xday or 2xweek for 9 mo)
- --------------------------------------------
- >Alternative first line therapy:
- Isoniazid + rifampin 1xweek for 12 weeks w/ DOT (= less time and fewer doses)
- -----------------------------------------------
- > Second line therapy:
- Rifampin (if INH res is suspected) (1xday, 4 mo)
-
Recommended Tx for active TB infection: drug susceptible
- > For drug susceptible organisms:
- Initial phase: isoniazid, rifampin, pyrazinamide, & ethambutol (2 mo)
- Continuation: isoniazid & rifampin
(4-7 mo, duration dep on presence of cavitary dz initially & positive sputum @ 2mo) - completion determined by total # doses taken, not duration of therapy
- lots of variations of therapy
-
Reccomended Tx for active TB: drug resistant
- > For drug res organisms:
- refer to clinical specialist, regiment based on expert opinion
- drugs can include: aminoglycoside (streptomycin, kenamycin, or amikacin), fluoroquinolones, capreomycin, aminosalicylic acid, cycloserine or ethionamideif suspect tx failure, never add a single drug (or res will be acquired quickly)
- ----------------------------------------------
- > Multi drug resistant TB (MDRTB):
- res to at least isoniazid & rifampin
- typically tx incld 5-7 drugs
- Tx cont for 18-24 mo OR 12-18 mo after culture becomes neg (LONG TIME)
- -----------------------------------------------
- > Extensively drug-resistance TB (XDRTB):
- Res to isoniazid, rifampin, any fluoroquinolone & either capreomycin, kenamycin, or amikacin
- Tx cont for 18-24 mo OR 12-18 mo after culture becomes neg (LONG TIME)
-
Adverse effects of TB tx (overview)
- GI upset very common in 1st few weeks--give with food
- drug interactions, esp w/ rifampin
- drug indiced hepatitis:
- can occure w/ INH, RIF, & PZA
- @ hi'er risk if previous hx of hepatitis, alcohol abuse
- Other:
- Rifampin: thrombocytopenia & acute remal failure
- Ethambutol: optic neuritis
-
Diuretic
Agent which increases the flow of urine.
Inhibit normal xport of sodium from filtrate into renal tubular cells OR block transcellular water absorption (V2 receptors)--> retention of H2O in tubule--> loss of water in urine
Most diuretics act on Na+ reabsorption
-
Natriuretic
Any agent which increases the excretion of sodium in the urine
-
Diuretics Mechanism of Action
- 1. Inhibit enzymes --> carbonic anhydrase, Acetazolamid
- 2. Osmotic effect --> mannitol
- 3. Block membrane transport proteins--> loop diuretics, thiazides, Aldosterone antagonists
- 4. Interfere with hormone receptors --> Aldosterone, V2 (ADH) receptor inhibitor
-
Tubular secretion
Process of diuretic delivery to apical membrane
Diuretic delivered to glomerulus on albumin and filtered by an ACTIVE process into the nephron
-
Clinical uses diuretics
- 1. Treatment of increased ECF --> cardiac disease, cirrhosis, renal failure (Acute/Chronic), hypoalbuminemia states, nephrotic syndrome, hormonal imbalance, SIADH
- 2. HTN
- 3. Maintenance of Urine output
- 4. Prevention of bladder irritation, especially during chemo
- 5. Prevention of precipitation of substances (Ca2+) in urine
- 6. Enhanced secretion of toxic cmpds --> salycilic acid
-
Diuretics that act on the PCT
Carbonic anhydrase inhibitors --> acetazolamide, dorzolamide
Osmotic Diuretics --> mannitol, glycerol
-
Diuretics that act on the DCT
Loop diuretics --> furosemide, butmetanide, torsemid
Thiazide and related diuretics--> HCTZ, metolazone, Indepamide
-
Drugs that act on the cortical collecting duct
Aldosterone antagonists--> spironolactone, eplerenone (receptor blockers)
Potassium sparing diuretics --> amiloride, tramterine (block eNAC channels)
ADH (aka: vasopressin) antagonists
Selective V2 receptor antagonists --> tolvaptan
Combined V1a/V2 --> Conivaptan *useful in SIADH
-
Carbonic Anhydrase inhibitors --> Acetazolamide, dorzolamide
MOA: reversibly inhibit carbonic anhydrase, decrease hydration of carbonic acid--> decrease Na+/H+ exchange by shutting down NHE3 pump, no HCO3- reabsorbed --> lost Na+
Clinical uses --> glaucoma, epilepsy, acute mountain sickness, urinary alkalinization, salycylate poisoning
Adverse reactions --> fatigue, HA, parasthesias, hypokalemia, renal stones, METABOLIC ACIDOSIS
-
Osmotic Diuretics --> mannitol, glycerol, urea
MOA: pharmacologically inert, filtered at glomerulus, minimally reabsorbed in tubules --> prevent movement of water trans/paracellularly --> RAPIDLY EFFECTIVE
Clinical uses: cerebral edema, glaucoma, oliguria or acute renal failure (increased urinary output), ENHANCE URINARY EXCRETION OF TOXINS
Adverse Reactions --> cellular dehydration, overly rapid fluid loss (esp in pts with normal renal function) and electrolyte abnormalities (hypernatremia, hypokalemia)
-
Loop diuretics --> Furosemide, bumetanide
- MOA: inhibit Na/K/2CL transport--> stops 20-25% Na+ reabsorption. Rapid onset of action (Oral <1hr; IV = 2-10 mins) with short duration of action
- 1. Give furosemide Q12 oral, Q 4-6 IV
- High ceiling diuretics --> continue to increase dose and still get a response but has a 'breaking phenomenon' with magnitude of natriuresis of diuretic declines over time
Clinical uses --> HTN (when CrCl <30 ml/min in association with metazolone) Edema, Acute renal failure, hyperkalemia, anion overdose (bromide, fluoride, iodide)
- Adverse reactions --> hypovolemia, electrolyte abnormalities (hypokalemia, hypochloremia, hypomagnesmia, and hypocalcemia), hyperuricemia (gout), oxotoxicity (hearing and balance), impaired platelet aggregation, tolerance
- ALSO similar adverse reactions as sulfonamide derivatives --> skin rash, eosinophilia, interstitial nephritis, allergic cross reactivity
-
Thiazides--> hydrochlorothiazide (HCTZ), chlorithalidone, Metolazone, indapamide
- MOA: inhibit NCC symporter in distal tubule
- --> HCTZ most commonly used 70% bioavailability, t1/2=9 hrs, duration of action = 12 hrs, 12.5-25 mg given once daily with flat dose response curve
--> chlorithalidone better than HCTZ for decreased M&M and increased potency, t1/2=60 hrs, given 12.5-25 mg once daily
- --> Metazolone 65% bioavailability, t1/2=8hrs, duration of action= 8 hrs
- --> Indapamide 90% bioavailabilty, t1/2=16 hrs, duration of action = 24 hrs
Clinical uses:
HTN (preferred use for HCTZ and chlorthalidone)--> decrease in SBP by 10-15 and DBP by 5-10. Works much better for HTN with decreased Na intake. May use metolazone for HTN for low CrCl with loop diuretic
- Other clinical uses:
- heart failure (chronic), Edema (less effective than loop diuretics), nephrolithiasis (hypercalciniuria), nephrogenic diabetes insipidus
Adverse reactions --> hypokalemia (keep K >4.0), hyperglycemia (minor), hyperuricemia, metabolic alkalosis, decreased Ca2+ excretion, hyperlipidemia (minor increased cholesterol and LDL)
-
Aldosterone Antagonists --> spironolactone, eplerenone
- MOA --> competitive inhibition of MR aldosterone receptor acts at distal renal tubule
- Spironolactone = non-selective, give 25 mg QD, increased NaCl excretion while conserving K+ Eplerenone= selective, very new, give 50-100 mg/day, contraindicated with CrCl < 50 ml/min, expensive but useful for males unable to tolerate spironolactone
Clinical uses: prevent or treat hypokalemic alkalosis esp in combo with thiazide diuretic, heart failure (eplerenone), cirrhosis with ascites (spironolactone), resistant HTN, hyperaldosteronism
Adverse effects: hyperkalemia --> increased risk in chronic kidney disease, receiving K+ supplements, ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, gynecomastia, BPH, loss of libido, impotence, menstrual irregularities ( endocrine effects less with eplerenone)
-
Potassium sparing diuretics--> triamterene, amiloride
MOA: block ENaC directly from apical membrane (aldosterone function antagonists)
Clinical uses: Prevent or treat hypokalemic alkalosis, esp in combo with a thiazide diuretic, HTN (most commonly combined with HCTZ to make Dyazide, not as a monotherapy), hyperaldosteronism
Adverse rxns: Hyperkalemia, nausea, vomiting, dizziness, leg cramps, acute renal failure (triamterene+indomethacin), kidney stones (triamterene)
Caution: with ACEIs, ARBs, and renal failure that also raise K levels
-
ADH antagonists (vaptans) --> conivaptan, lixivaptan, tolvaptan
MOA: selective non-peptide V2 receptor antagonists (V2RA)
Clinical uses: SIADH, heart failure, cirrhosis
-
Urinary Tract Infections: General guidelines
- Uncomplicated cystitis: usual pathogen = Escherichia coli, tx for 3-5d w/ appropriate antibiotic w/o urine culture
- Complicated cystitis: tx for 7d, culture + f/u culture
- pyelonephritis: tx for 10-14d, ideally w/ cultures (blood & urine) + f/u culture
- asymptomatic bacteriuria in elderly should NOT be tx'd
- patients w/ indwelling catherter w/o sx of UTI should NOT be cultured or tx'd
-
Drugs of Choice for uncomplicated cystitis
- > 1st line:
- Nitrofurantoin (BID for 5d): old agent, only UTI (not hi enough plasma conc for other)
- TMP-SMX DS (BID for 3d)
- if local res rates <20%--------------------------------------------------
- > 2nd line:
- Ciprofloxacin (BID for 3d): lo dose, res develops fast
- B-lactam (ie cephalexin) (3-7d): 1st generation cephalosporin, conc in urine
-
Drugs of choice for pyelonephritis
- Ciprofloxacin (BID for 7d): hi'er dose than uncomplicated b/c it's systemic (= full dose)
- TMP-SMX DS (BID for 14 d) if pathogen susceptible
-
Trimethoprim-Sulfamethoxazole
- Synonyms:
- co-trimoxazole
- TMP-SMX
- SMX-TMP
- Bactrim SS, Bactrim DS
- Septra SS, Septra DS
- -------------------------------------------
- Dosage:
- 5:1 ratio of SMX-TMP
- single strength (SS) = SMX 400mg:TMP 80 mg
- for elderly or if dec renal func
- Double strength (DS) = SMX 800mg:TMP 160mg
-
Sulfa Allergy
- sulfonamide antibiotic allergy in 3 % pop
- controversy about whether other drugs containing sulfonamide moiety will cross react w/ sulfa antibiotic allergy
- pt w/sulfa antibiotic allergy can usually take other sulfa drug categories
- rxn to non-antibiotic sulfa drugs seems ass with general susceptibility to allergies
- 3 sulfa drug classifications:
- sulfonylarylamines (incld sulfa antibiotics) [= true sulfa drug]
- non sulfonylarylamines
- sulfonamide moiety containing drugs
-
Chronic UTI prophylaxis
- > 3 episodes of cystitis per yr
- give low, once daily dose of antibiotic for 6 mo - 1 yr
- Drug of choice: TMP-SMX
- Alt drugs:
- TMP alone (SMX intolerance)
- Fluoroquinolones (if res to TMP-SMX)
- Nitrofurantoin
- -nausea more common, must take w/ food
- ->'er change of long-term effects (ie pneumonitis, drug-induced liver injury
- -active vs Enterococcus in urine, unlike other drugs
-
Urinary analgesics
- symptomatic relief of pain, urgency, burning, & freq ass with lower UTI
- does NOT tx infection
- > Drugs:
- phenazopyridine
- colors urine/clothes red-orange
- OTC
- Flavoxate (Urispas)
- anti-cholinergic side effects
-
TX of Acute Prostatitis
- pathogens usually similar to those of UTI
- ID pathogens by urine culture
- therapy for 4 wks
- TMP-SMX
usually drug of choice unless contraindicated by allergy or drug interaactions - fluoroquinolones for G- bacteria not sensitive to TMP-SMX
-
Tx of Chronic Prostatitis
- common cause of recurrent UTI in men
- inflammation < acute prostatitis
- penetration of antibiotics into prostatic tissue can = difficult
- drugs: TMP-SMX (usually) or fluoroquinolones (same as for acute prostatitis) but must give for 6 - 12 weeks (= longer than acute prostatitis)
- usually try TMP-SMX first, then try fluoroquinolones
-
Usual suspects for intra-abdominal infections (case 2, G- lecture)
- G-:
- Escherichia cole
- Klebsiella spp
- Proteus spp
- Pseudomonas aeruginosa (if hospital-acquired)
- G +:
- Enterococcus
- Anaerobic
- lots*
- ----------------------------------------------
- Presumptive Tx:
- Make sure cover for all of these until get cultures
- *esp bacteroides fragilis
-
Recommended Agents for Intra-abdominal (mixed) infections
- > single agents w/ G+/- & anaerobic coverage
- Piperacillin-tazobactam
- incld Enterococcus activity
- Doripenem
- Imipenem derivative, longer T1/2
- most res of B-lactams to extended spectrum B-lactamases
- NO Enterococcus activity
- -----------------------------------------------
- > Combo therapy (no Enterococcus activity)
- Ceftriaxone or cefotaxime + metronidazole
- Levofloxacin or moxifloxacin + metronidazole
- Aztreonam + metronidazole
- no G+ activity
-
Anaerobic infections
- GI:
Bacteriodes fragilis: common bacterium in distal small bowel & colon - always assume lower GI tract infections involve it
- Respiratory:
- Peptostrptococcus: can cause aspiration pneumonia from inhalation of upper GI bacterial flora
- Skin & soft tissue:
- Clostridium perforinges: causative agent of gas gangrene
-
Clostridium difficile infection & tx
- AKA: antibiotic-associated colitis, pseudomembranous colitis
- --> severe diarrhea (bc of toxin)
- = anaerobic bacteria
- ------------------------------------------------------
- Tx:
- discontinue inciting antibiotic
- mild-moderate infection:
- oral metronidazole (TID for 10-14d)
- abs systemically but hi conc reach colon when inflammed
- Severe Infection:
- oral vancomycin (QID for 10-14d)
- not abs => hi conc in colon
- Life threatening infection:
- oral vancomysin (QID) + IV metronidazole (TID) (for 10-14d)
-
Antibiotics for Anaerobic infections
- > metronidazole - best agent (oral or IV)
- excellent tissue penetration, incld CNS
- rapidly bactericidal
- also has local anti-inflammatory activity in GI
- pool activity vs mouth flora anaerobes
- alcohol intolerance due to inhibition of aldehyde dehydrogenase - AVOID alcoholic beverages
- every 8 hrs
- -----------------------------------------------
- > Clindamycin:
- good anaerobic activity but more adverse effects, incld antibiotic-ass diarrhea & potential Clostridium difficile infection
- ----------------------------------------------
- > Penicillin/B-lactamase inhibitor combo:
- oral: amoxicillin/clavulanate
- IV: piperacillin/tazobactam (Zosyn)
-
Aminoglycosides antobiotics
- gentamicin, tobramycin, & amikacin
- Use: primary agent for seious G- infections before fluoroquinolone
- still use in combo w/ cephalosporins & quinolones for G- infections (esp Pseudomonas)
- oly IV or IM
- *Usually = single hi dose daily (conc dep killing) [one of few]
- limited use b/c of renal toxicity & ototoxicity
- monitor serum levels
-
Pseudomonas aeruginosa infections
- > Urinary tract:
- Ciprofloxacin
- ------------------------------------------------
- > Systemic infections:
- Pipperacillin/tazobactam +/- tobramycin
- ceftazidime or cefepime +/- tobramycin
- meropenem or doripenem +/- tobramycin
- -------------------------------------------------
- > Pulmonary infections:
- same as above but add aminoglycoside
- inhaled tobramycin also available for cystic fibrosis patients
-
Hospital acquired pneumonia (HAP)
see lecture "gram negative infections & STD" slides 35-40
-
Bacteremia & Sepsis/Tx
- Pos blood cultures: draw 2 sets, different IV sites
- antibiotic choice dep on probable source:
- skin
- intra-abdominal
- pulmonary
- urinary (confusion & delerium in elderly)
- also dep on immune status
- usually give IV antibiotics
- *use bacteriocidial antibiotics
-
Deep seated infections
- must isolate causative organism
- hi'est doses of antibiotic necessary
- usually IV
- Osteomyelitis
- usually due to Staph
- multiple organisms ass w/diabetic foot wound
- Menigitis
- blood-brain barrier must = penetrated
- inflammed (meningitis) meninges allow greater antibiotic penetration than uninflammed meninges (abcess)
- intrathecal route may be necessary
-
Chlamydia Tx
- (Chalmydia trachomatis)
- Azithromycin: 1 dose, primary tx (good adherence)
- doxycycline: 7d PO
- Alternatives:
- erythromycin PO 7d
- levofloxacin PO 7d (no fluoroquinolones <18 yo)
- doxycycline & levofloxacin contraindicated in pregnancy
-
Gonorrhea Tx
- (Neisseria gonorrhoeae)
- ceftriazone (IM, 1 dose) PLUS azithromycin (1 dose) or doxycycline (BID, 7d)
- co-treatment w/ azithromycin or doxycycline is for possible Chlamydia
- fluoroquinolones or oral cephalosporins no longer recommended due to hi res rates (ceftriaxone is all we have left)
-
Pelvic Inflammatory Disease (PID) Tx
- polymicrobial infection possible involving Chlamydia trachomatis, Meisseria gonorrhea, anaerobic bacteria, & G- bacteria
- Outpatient:
- ceftriaxone (IM, 1 dose) +
- doxycycline (BID, 14d) with or w/o
- metronidazole (BID, 14d)
- Inpatient:
- give IV until able to tolerate oral antibiotics
- cefotetan (IV) plus
- doxyclycline (IV)
- OR
- clindamycin (IV) plus
- hi dose gentamicin IV daily
-
Nongonococcal urethitis Tx
- Ureaplasma urealyticum OR Mycoplasma genitalium
- usually responds to azithromycin OR doxycycline at same doses as for Chlamydia trachomatis
-
Trichomonas Tx
- (Trichomonas vaginalis, an anaerobic protozoan)
- Metronidazole (oral, 1 dose)
-
Bacterial Vaginosis Tx
- Gerdnerella vaginalis, Mycoplasma hominis, & various anaerobes
- Metronidazole (PO, BID, 7d)
- Metronidazole gel (intravaginally, QD, 5d)
-
Syphilis Tx
- (Treponema pallidium = spirochete)
- Penicillin G benzathine (IM, 1 dose for primary or secondary infections)
- doxycycline (PO, BID, 14d): if allergy
- Penicillin G benzathine IM weekly, 3 doses for tertiary infections
- hi dose Penicillin G (IV, 10-14d for neurosyphilis)
one of the few times penicillin is 1st line/used
-
Where is the most up to date info about STD guidelines for tx?
CDC web stie
-
Hypertension: Basic Principles
- 1. BP= CO x PVR
- 2. Regulated at different sites throughout the body
- a. Arterioles
- b. capacitance venules
- c. Cardiac output
- d. Renin-Angiotensin- Aldosterone system
- 3. Regulated by many different mechanisms/substances
- e.g. sodium, catecholamines, dilators,
- autoregulation, etc
-
Primary vs. Secondary HTN
- 1. Primary/essential HTN is 95% of cases
- 2. Seconday causes --> obesity, sleep apnea, drug induced (NSAIDS, corticosteroids, contraceptives, cocaine, etc), pheochromocytoma, primary aldosteronism, Cushing syndrome, Coarctation of aorta, thyroid/parathyroid disease, pregnancy
- 3. White Coat HTN --> occurs only in medical setting mostly in young females w/o long HTN Hx --> consider outpatient BP monitoring for all HTN patients
-
Reasons to treat HTN
- Target organ damage
- 1. Stroke/TIA
- 2. Retinopathy
- 3. Heart Disease --> LVH, HF, angina, ACS
- 4. Chronic kidney disease
- 5. Peripheral artery disease
*note --> most clinical trials for HTN measure long term effects on target organs (improvement/prevention of TOD)
-
HTN Treatment guidelines- General
- 1. JNC 7 --> came out in 2003 but is outdated
- still the standard for the US.
- 2. Individual fields of specialty have come out with more recent guidelines
- --------------------------------------------
- Note: most patients will need at least 2 anti-HTN drugs to reach BP goal (esp if BP is >20/10 mm Hg above goal) --> ALWAYS EMPHASIZE LIFESTYLE MODIFICATIONS
-
JNC 7 Classification of HTN
- 1. Normal < 120/80
- 2. Pre-HTN = 120-139/80-89
- 3. HTN
- a. Stage one--> systolic 140-159 or Diastolic 90-99
- b. Stage 2 --> systolic >160 or diastolic > 100
-
Blood Pressure Goals (JNC 7 and others)
- JNC 7
- 1. Uncomplicated HTN < 140/90
- 2. DM/CKD < 130/80
American Heart Associated (2007)
- 1. Documented CAD , 130/80
- 2. Heart Failure in Stages B-D < 120/80
- 3. (2001) Systolic BP goal of 140-145 in the very old (80+ yo)
- NKF-KDIGO (2012
- 1. CKD patient with <30 mg albumin loss/24 hrs < 140/90
- 2. CKD patient with >30 mg albumin loss/24 hrs <130/80
-
Treatment Guidelines for HTN
- 1. Start with lifestyle modifications --> weight loss, DASH Diet to decrease salt intake, physical activity increase, reduce EtOH intake
- 2. No compelling indications --> add diuretics (normally start with Thiazide for stage 1 and add other meds such as Beta-blockers for stage 2)
- 3. Compelling co-morbidities --> add HTN medications that will help with co-morbities
- -------------------------------------------------------
- Initial Combinations of HTN drugs --> Thiazide diuretic + ACEI or ARBs + Calcium antagonists
- -at least 2 of these 3
- Then add beta-blocker with compelling indication (MI, angina, LV dysfunction)
- --------------------------------------------------------
- Resistant HTN --> caused by improper BP measurement, volume overload, no lifestyle modifcation, medications (NSAIDS, OTC meds)--> investigate these possibilities before adding other drugs
For resistance to primary therapy --> switch for HCTZ or clorthalidone, add aldosterone antagonists, switch BB to labetelol, add alternatives such as alpha receptor blockers, central alpha receptor agonists, or vasodilators
-
ALLHAT Trial
Conclusion: "Thiazide type diuretics are superior in preventing one more major forms of CVD and are less expensive"
--> THIAZIDES ARE FIRST LINE FOR HTN
-
Compelling indications for High risk conditions + HTN treatment
Memorize this table in the slides. It comes up at least twice (slide 32 is the first)
-
Renin-Angiotensin-Aldosterone System
- 1. Process
- Decrease in BP--> kidneys secret renin --> renin converts angiotensinogen to AT1 --> ACE converts AT1 to AT2--> sympathetic activation, vasc sm. mm. contraction, aldosterone secretion --> increase BP
- 2. Several sites of action of drugs for this system
- a. Renin <-- aliskiren
- b. ACE <-- ACE inhibitors
- c. Angiotensin receptors <-- ARBs
-
ACE Inhibitors
1. MOA --> inhibit action of Angiotensin converting enzyme
2. Generic names end in -pril --> Captopril (1st drug, only used for HTN emergencies now), Lisinopril (most frequently prescribed), Enalaprilat (IV formulation)
3. Most are prodrugs that are metabolized to active agent in the liver (except lisinopril)
4. Always start with low dose and titrate up slowly (wks-mos) to avoid adverse effects (esp in pts w/ renal dysfunction)
5. given QD or BID (except Captopril)
6. AVOID NSAIDS--> lose ability to maintain renal autoregulation (renal failure potential)
7. Adverse Effects --> hypotension, hyperkalemia, renal failure (esp if CHF, hypovolemia, renal artery stenosis, and NSAIDS), rise in serum creatinine (use up to 30% rise), dry cough (5-15%, make sure its not asthma), angioedema (much more prevalent in African Americans), Teratogenic in pregnancy (Category D)
-
Angiotensin II receptor blockers (ARBs)--> Losartan, Irbesartan etc
1. MOA - block AT1 receptors in vasc sm. mm and adrenal complex --> vasodilation, decreased aldosterone release, decreased sympathetic activation
2. Generic names end in -sartan --> Losartan, Irbesartan (most used)
3. Adverse Effects --> hyperkalemia, angioedema (less likely than with ACEI), cough (less likely than with ACEI), teratogenic in pregnancy (Category D)
4. Used to manage HTN in pts to avoid cough and angioedema
-
Can you combine ACEIs and ARBS
1. NO!
2. ONTARGET Study --> higher incidence of discontinuation, renal impairment, renal failure, in combo group
-
Direct Renin Inhibitors
1. MOA --> inhibit renin and prevent formation of AT1 and AT2
- 2. Indications --> HTN either alone or in combo w/other agents. Safe in short term, well tolerated, similar in efficacy to ACE inhibitors and ARBs, give 150 or 300 mg QD
- 3. Cost about $160/month
4. Basically equal to ACEIs or ARBs, nothing too special
5. Aliskiren approved in 2007 (only drug)
-
Drugs for used in African American population
- 1. HTN in AA population is mostly of the low renin type.
- 2. Use diuretics (HCTZ) first with diet modification to reduce salt intake
- 3. Don't need to avoid ACEIs or ARBs entirely
- 4. Generally two drugs are necessary for BP control in AA population, blunted response to anti-HTN drugs goes away with combination therapy such as...
- a. ACEIs and CCBs
- b. ACEIs and Thiazide diuretics
- c. ARBs and diuretics
- d. Beta-blockers and diuretics
-
Beta blockers in HTN
1. MOA: block Beta-receptors in the heart and other tissues --> decrease myocardial O2 demand, renin secretion, and sympathetic outflow
2. Selective --> Atenolol, Esmolol (IV only), Metoprolol (most common)
3. Non-selective --> Propanolol, Nadolol, Timolol
4. Renal elimination --> Atenolol, Nadolol
5. Intrinsic sympathomimetic activity (less effect on resting HR) --> acebutelol, pindolol
6. With alpha blocking activity --> Labetalol (greater decrease in BP, used for resistant HTN, hypertensive urgencies, hypertensive emergencies, both IV and oral, watch for orthostatic HTN), Carvedilol (used for heart failure)
7. Adverse effects --> bronchospasm, bradycardia (HF), masking of DM Sx, impaired peripheral circulation, sexual dysfunction, CNS toxicity, elevated TG, decreased HDL, exacerbation of angina and MI if discontinued suddenly.
8. Contraindicated in --> symptomatic hypotension, symptomatic bradycardia, severe pulmonary disease, severe peripheral vascular disease, heart block, heart failure, and cardiogenic shock
9. Used to treatment of HTN in patients with comorbities of angina, history of MI, or LV dysfunction
-
Calcium Channel blockers in HTN
1. MOA: bind L type CCBs to prevent influx of Ca2+ --> cause vascular smooth muscle relaxation, reduced BP, and reduced intramyocardial wall tension.
- 2. DHP-CCBs --> amlodipine is preferred for HTN, Nifedipine is prototype
- a. metabolized by CYP 3A4
- b. short T1/2
- c. Adverse effects --> fatigue, HA, flushing,
- peripheral edema, heart failure
- d. Severe hypertensive episodes with
- sudden discontinuation
3. Non-DHP CCBs --> not normally used for HTN, used as anti-arrhythmics (see previous cards for info)
-
Peripheral Alpha-1 receptor blockers
1. MOA: block peripheral alpha 1 receptors in sm. mm --> vasodilation and decrease PVR
2. Doxazosin, prazosin, Terazosin
3. Adverse effects --> orthostatic hypotension, first dose syncope. NOT FIRST LINE OR MONOTHERAPY
4. May be beneficial for patients with BPH
-
Centra alpha-2 agonists
1. MOA: stimulate alpha-2 receptors in the brain to decrease sympathetic outflow --> decrease PVR, HR, and CO
2. Clonidine (weekly patch or oral tablet) and Methyldopa
3. Still used alot in hampton roads
4. Adverse effects --> sedation, dry mouth, orthostasis, dizziness, erectile dysfunction, sever rebound HTN if stopped suddenly (tapered discontinuation ALWAYS)
-
Direct Vasodilators
1. MOA --> direct arteriolar Sm. mm. vasodilation --> decreased PVR, but increased HR, CO, and renin
2. Hydralazine (decreased afterload, must give 3x/day, give with diuretic and beta blocker for reflex tachy and water retention, may cause lupus like syndrome with higher doses), Minoxidil (give with beta-blocker and diuretic for reflect tachy and severe fluid retention, causes hirsutism)
3. not used often for HTN
-
Drugs with favorable effects on Comorbitities
- 1. Osteoperosis --> thiazide diuretics
- 2. Atrial Tachyarryhtmia, A-fib --> beta blockers/CCBS
- 3. Migrain HA, tremor --> beta blockers
- 5. Thyrotoxicosis (short term) --> beta blockers
- 6. Perioperative HTN --> beta blockers
- 7. Raynaud's Syndrome, arrythmias --> CCBs
- 8. BPH/Prostatism--> alpha blockers
-
Potentially unfavorable effects on Comorbidities
- 1. Asthma/RAD --> Beta blockers
- 2. Gout or serious hyponatremia --> thiazide diuretics
- 3. Heart block --> beta blockers, non-DHP CCP
- 4. Pregnancy--> ACEI, ARB
- 5. H/O angioedema --> ACEI
- 5. Serum K > 5.0 meq/L not on meds --> aldosterone antagonists, and K sparing diuretics
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Pregnancy and Hypertension
- 1. Special case --> HTN major cause of maternal/fetal/neonatal M/M --> may progress to pre-eclampsia or eclampsia
- 2. Methyldopa --> drug of choice (Category B)
- 3. DO NOT USE ACEIS and ARBs (teratogenic) ,
as well as labetalol, atenolol, and diuretics - 4. Labetalol can be used for pre-eeclampsia as well as hydralazine in emergencies
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Hypertensive Urgency
- 1. Markedly increased BP > than 180/120 without acute target organ damage that normally does not require hospitalization
- 2. Tx with oral short-acting agens --> captopril, clonidine, labetalol
- 3. Antihypertensive therapy adjustment with combination therapy to improve adherance and close F/U
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Hypertensive Emergency
1. Markedly increased BP > 180/120 with ACUTE target organ damage --> CVA, encephalopathy, MI, UA, pulmonary edema, HF, eclampsia, aortic dissection, renal failure
2. Requires hospitalization and IV drug therapy
3. Tx --> Sodium nitroprusside by IV infusion but MONITOR thiocyanate levels (don't use too long), labetalol, fenoldopam by IV infusion (dopamine receptor agonist--> arteriolar vasodilation) --> decreased PVR and increased renal blood flow
4. Goal to decrease MAP by 25% w/i 1 hr then BP to 160/100-110 within next 2 hrs, normal BP within 1-2 days
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