-pharmodynamics- causes generalized vascular + coronary vasodilatation
- ⋀ blood flow via coronary arteries to myocardial cells
- ⋁myocardial ischemia but ⋁ BP
- Variant ( vasospastic) Angina=
- - Relaxes coronary arteries=> ⋁ vasospasm +⋀ O2 supply
- Classic ( Stable ) angina
- - dilates veins => ⋁preload and ⋁ O2 demand
- PO/ SL: comes in many doses
- most common SL=> readily absorbed vs. swallowed=> bypass 1st pass effect
- -SL onset 1-3 mins, duration 10 mins
- - tabs decompose when exposed to sunlight = keep in specialized case.( 0.4 mg)
nitro other routes
- -IV dose
- dilute with D5w or 0.9% NaCl
- use glass infusion bottle and non polvinyl tubing cuz NTG absorbed via plastic
- -Topical= apply transdermal path to chest or thigh. remove after 8-12 hours and wipe site.
- PO-extended release capsule.
- -reduces 02 demand
- -acts on smooth muscle of blood vessels
- relax and dialation
- ∨preload = amount of blood in RV at end of diastole.
- ∨ afterload= peripheral vascular resistance
- -enhanced if given + β blockers, Ca ++ channel blockers, antiHTN, ETOH
- - IV NTG will decrease Heparin effects.
- - Don't give with Antihypertensives like viagra, cialis, levitra.
NTG: Side Effects
- H/A ( Most Common). May decrease with contd usage
- - ∨ BP, dizziness, weakness, faintness.
- - rebound myocardial ischemia if NTG is not tapered.
- - reflex tachycardia if NTG pushed too quickly
- - watch for circulatory collapse.
- block β1 and β2 receptor sites
- - ∨ effects of sympathetic NS via blocking ax of catecholamines
- ( Epinephrine and Norep)
- - ∨ HR and BP
- - antianginal, antidysrhythmic, antihypertensive
Beta Blocker Contraindications + interactions
- ∨ HR & BP
- 2nd or 3rd degree AV block( conduction disturbances and possible death)
Nonselective β- blockers
- Propanolol ( Inderal)
- - ∨ HR & BP
- - Adverse reaction
- behavioral or psychotic rx
- - look closely at V/S
- - Assess lungs before dose
Selective β blockers ( mostly β1)
- Metoprolol ( Lopressor)
- - ∨ HR & BP
- - monitor VS closely in early Tx
Ca++ channel blockers
- -neg inotropic effect: relaxation of smooth muscle.( Contractility)
- ∨ workload and O2 demand.
- - ∨ afterload ∨ peripheral resistance
- ∨workload & O2 demand
- Effective for
- Classic ( stable): O2 demand by relaxing peripheral arterioles.
- Variant ( vacospastic): Relaxes coronary arteries.
- Other uses:
Ca++ blocker side effects
- - hypotension
- - dizziness
- -reflex tachycardia r/t ∨ BP
- - changes in liver & kidney f(x): √ labs
- -don't push Nifedipine unless in SCD ( severe BP crisis)
Nifedipine ( Procardia)
- - Ca ++ channel blocker
- -most potent
- -HYPERTENSION CAN OCCUR ( don't push)
- - Highly protein bound
Amlodipine ( Norvasc)
- - Ca++ blocker
- -Most recently invented
- - highly protein bound
Ca++ channel blocker Assessment
- - Monitor BP & pulse
- - Monitor EKG periodically => can prolong PR interval
- -monitor I & O / daily wt
- - assess for signs of CHF
- peripheral edema, crackles, dyspnea, wt gain, JVD
- - IF on digoxin, monitor for serum digoxin level for toxicity.
Anti-Anginals planning and ct teachings
- - increase activity level in proportion to PT tolerance.
- CT teaching
- Instruct re: proper administration & possible drug interactions
- - Notify HCP if angina unrelieved
- - do not D/C without HCP
- -Edu for S/E
- - β blockers and Ca++
- teach to take own pulse
- => W/D sx severe
Physiologic Risk Factors HTN
- Excess fat + carbs
- Carbs can affect sympathetic NS
- Renin secretion=> ∧ angiotension II
- ∧ CO, SV & Left Ventricular filling
- - 2/3 of HTN's obese
- Normal wt loss & mild to mod Na+ restriction => ∨ HTN
- Normal <120/ <80
- Pre- 120-139/80-89
- 1 - 140-139/ 90-99
- 2- >160 />100
- -African-Americans get HTN at earlier age + have higher Mortality than whites
- < effective β blockers + ACE inhibitors
- > effective α1 blockers+ Ca++ channel blockers
- diuretics as 1° monotherapy
- - Asians 2 x's as sensitive as whites to β blockers and other anti-HTN's.
- usually need ∨ dose
- - Whites respond well to all Anti-HTN's.
- -Beta- Blockers
- - Alpha2 agonists
- - Alpha adrenergic blockers
- - ACE inhibitors
- - Angiotensin II receptor antagonists ( blockers)
- - direct renin inhibitors
- - Ca++ channel blockers
- - promote Na+ depletion => water depletion
- ( ∨ extracellular fluid volume)
- - 1° tx for mild HTN
- Loop Diuretics- Furosemide ( Lasix)- most powerful
- inhibit the exchange of Cl, Na, K in thick segment of the ascending loop of Henle.
- - Nausea, diarrhea, electrolyte imbalance (hypokalemia)
- K-sparing diuretics
- Inhibit reabsorption of Na in distal convoluted + collecting tubule.( no risk of hypokalemia)
- Thiazides ( hydochlorthizide)
- - Inhibit active exchange of Cl-Na in the cortical dilluting segment of the ascending loop of Henle.