Are Cephalosporins under optometry scope of practice in California?
YES
What is Cephalexin and Cefadroxil effective against? Resistance? Administered form?
Gram positive bacteria
NOT good for Gram negative in general, will not cover anaerobic bacteria, Pseudomonas or Enterococci
Many have acquired resistance to these agents
Available in oral form only
What is Cefaclor effective against? Resistance? Administered form?
many Gram positive bacteria
not good for Gram negative bacteria in general
Does not cover Enterococci or Pseudomonas
Available in oral form ONLY
Cefotetan has been re-approved in generic form in the USA. Should we prescribe this drug?
No, we should avoid Rxing this drug because it has an increased risk of bleeding interactions in patients taking anticoagulants/blood thinners.
Do cephalosporins need to be adjusted in patients who have renal impairment?
Yes in some of the cephalosporins
It is estimated that 2-10% of patients who are allergic to penicillin will also be allergic to ______.
cephalosporins
Allergies to cephalosporins may occus in _____% patients. Reactions may range from _______to _______.
5%
rash to anaphylaxis
Cephalosporins can cause anything from rash to anapylaxis. Other adverse effects include....
CNS: fatigue, dizziness, vertigo, HA
Dermatologic effects: rash and other manifestations of allergic responses are common. Exfoliative dermatitis is rare.
GI effects: N/V/D are common, hepatic and renal effects rarely occur
Blood dyscrasias: including eosinophilia, thrombocytopenia, neutropenia, and leukopenia occur but are infrequent
Fluroquinolones MOA?
inhibition of bacterial DNA gyrase which interferes with bacterial reproduction. Effects are often bacteriocidal. Most are broad spectrum
Fluoroquinolones are effective against what bacteria? Resistance?
Good = Some Gram +, many Gram -, most cover Chlamydia
No Good = MRSA, Enterococci (not recommended), Bacteroides (doesn't adequately cover)
bacterial resistances increasing
Name 7 fluroquinolones used in California.
1) Ciprofloxacin
2) Gatifloxacin
3) Levofloxacin
4) Moxifloxacin
5) Norfloxacin
6) Ofloxacin
7) Bestifloxacin
How long will most fluroquinolones be used to treat bacterial conjunctivitis? Corneal ulcers/keratitis?
7 days
5-14 days
T/F patients who are allergic to one fluoroquinolone will be allergic to all of the fluoroquinolones.
TRUE
We should avoid over-use of fluoroquinolones for conjunctivitis, what is a common side effect of over-use of this drug?
white precipitates of active drug at the site of epithelial defect that may be confused with a worsening infection
T/F there are numerous potential drug interactions, adverse effects, and cautions with oral use of fluoroquinolones.
TRUE
T/F we do not need renal dose adjustments for patients with renal impairment or renal disease when using fluroquinolones.
FALSE
What are the 5 cautions for ophthalmic preparations of fluroquinolones we should be aware of?
1) Be cautions with patients with seizure history
2) Can increase photosensitivity and cause photophobia
3) Potential adverse reactions: burning/stinging in eye, blurred vision, redness/irritation in the eye, eye ain, foreign body sensation, tearing, and/or dry eye.
4) Rare but potentially serious side effects: severe exfoliative dermatitis, severe allergic reactions like anaphylaxis, periocular or facial edema, dizziness etc.
Sulfonamides MOA?
They are structural analogs of PABA (Paraamino benzoic acid)
They competively inhibit the bacterial enzyme necessary for incorporating PABA into dihydrofolic acid, the folic acid precursor.
Inhibiting folic acid formation results in the bacteria not being able to synthesize amino acids and DNA.
Uses of sulfonamides? Bacterial resistance effect upon use?
Broad spectrum bacteriostatic antibiotics with specific antibacterial and antiprotozoal activities.
Acquired bacterial resistances have limited use of this class although for some uses this class of drugs is still someowhat medically important
ODs can Rx Sulfamethoxicin/Trimethoprim (SMX/TMP) which is used orally to treat _______________.
CA-MRSA
The Sulfonamides: Sulfacetamide sodium ophthalmic solution (10%, 15%, 30%) and 10% opthalmic ointment in addition to Sulfisoxazole 4% ophthalmic ointmentand 4% ophthalmic solution are used occassionally for treating what conditions? Is it good for CA-MRSA?
bacterial conjunctivitis and trachoma/chlamydial infections
not good for CA-MRSA
What are some potential adverse effects of sulfonamides?
Stinging and burning upon application
Allergic reactions possible
Cross-reactivity with other sulfa drugs
Dermatologic reactions range from swelling to hives and rash
Severe exfoliative dermatitis is potentially possible
Products are incompatible with silver-containing preparations
Polymyxin and Bacitracin MOA?
Polymyxin = bactericidal agent works by binding to cytoplasmic membranes, disrupting structure and altering membrane permeability
Most effects are against sensitive Gram-negative bacteria.
Bacitracin= bactericidal agent works by binding to bacterial cell membranes and interfereing with cell wall synthesis.
Most effects are against sensitive Gram positive bacteria.
Uses for Polymyxin and Bacitracin both singly and in combination with other anti-infectives include...
Also what about bacterial resistance?
short-tern treatment of external ocular infections caused by susceptible bacteria
NOT for long term treatment
Acquired bacterial resistance has impacted former widespread usage
Adverse Effects of Polymyxin and Bacitracin?
Local adverse effects are possible, should check previous patient sensitivity reactions before usage.
Tetracyclines MOA?
Inhibits bacterial protein synthesis by binding to the 30S subunit (remember by: Thirty Tetracyclines.)
What types of bacteria are Tetracyclines effective against?
Variable effects against some Gram-positive
bacteria
Systemic Listeria infections
Some Gram negative bacteria including Neisseria meningitidis and Legionella
Mycoplasma, Chlamydia, Rickettsia
Some anti-clostridial activity but not C. difficile
O.D.s Rxing for oral use should be rare and considered for very specific conditions only like...
chlamydial inclusion conjunctivits, trachoma
Oral tetracyclines includes __________ and _________
doxycycline and tetracycline
There are many potential adverse effects and drug interactions possible with the use of tetracyclines antibiotics. Tetracyclines should be used by ODs
sparingly and with caution. What are some specific Adverse Effects of Tetracyclines?
a) Many drug-to-drug and drug-to-food interactions exist
b) Photosensitivity
c) GI effects: antibiotic-associated pseudomembranous colitis, N/V, abdominal pain, potential pancreatitis, hepatic effects
d) Allergic reactions possible. Cross-sensitivity exists between agents in the same class.
Avoid use of tetracyclines in pregnancy and with children. How often should they be prescribed in optometry practice?
VERY RARELY
Macrolides MOA?
Inhibits protein synthesis by binding to the 50S ribosomal subunit.
What bacteria are Macrolides effective against?
a) some Gram positive (Group A,B,C,G Streptococcus, Streptococcus pneumoniae, MSSA, Listeria)
b) some Gram negative bacteria (N. meningitidis, M. catarrhalis, H. influenzae, Legionella)
c) NOT good for Mycoplasma, Chlamydia, Rickettsia and some Clostridia (not C. difficile)
Of the Macrolides, __________ is used to treat eyelid infections and chlamydial disease manifesting in the eyes and __________ ophthalmic ointment is still available for superficial ocular infections and neonatal conjunctivitis.
azithromycin
erythromycin 0.5%
which of the following macrolides need to be adjusted for renal impairment?
erythromycin, clarithromycin = need to be dose adjusted
azithromycin = does not need to be need to be
Macrolides are either taken orally or parenterally, what are 5 adverse effects that can occur from taking these drugs?
a) Hepatic complications (hepatitis, jaundice)
b) Renal complications
c) GI effects (GI irritation, N/V/D)
d) ototoxicity may occur
e) allergic reactions (cross reactivity between agents in this class possible. Allergic reactions can range from rash to anaphylaxis.)
When prescribing Macrolides, what are two cautions we should be aware of?
1) patients taking blood-thinning medications
2) monitor for appearance for a super infection
Aminoglycosides MOA?
Inhibition of bacterial protein synthesis by binding to 30S and 50S ribosomal subunits (remember Aminoglycosides, All subunits)
MOA is specifically bacteriocidal
Can cause cell death through cytoplasmic membrane disruption
What bacteria are aminoglycosides effective against?
Gram + and - bacteria
MSSA (sometimes)
NOT against atypical bacteria, no anaerobic effects
Three aminoglycosides ophthalmic products are commonly used what are they?
a) gentamicin 0.3% ointment and solution
b) tobramycin 0.3% ointment and solution
c) neomycin (in combo with other anti-infectives like polymyxin, bacitracin etc.)
Adverse Effects of aminoglycosides?
Local irritation with ophthalmic use
Caution in myasthenia gravis patients
(potential for neuromuscular junction blockade effects can worsen/exacerbate symptoms)
What are the four Antiviral Agents we need to know ?
Trifluridine 1% ophthalmic solution
Vidarabine 3% ophthalmic ointment
Oral acyclovir
Valacyclovir
Trifluridine 1% ophthalmic solution and Vidarabine 3% ophthalmic ointment are both indicated for use in what cases?
What's their MOA? (they're different from each other)
Herpes simplex-related keratitis and keratoconjunctivitis.
Trifluridine 1% ophthalmic solution: incorporates in place of thymidine into viral DNA weakening viral ability to infect tissue (don't use prophylatically)
Vidarabine 3% ophthalmic ointment: inhibits viral DNA polymerase, prevents lengthening or building of DNA viral chains (don't use to treat infections caused by adenoviruses)
What are some of the adverse side effects that Vidarabine 3% ophthalmic oitment can cause? Also, what kind of agent is this drug?
a) local hypersensitivity reactions: itiching, redness, foreign body sensation, swelling, pain, burning, other irritation on application
b) increase flow of tears
c) sensitivity of eyes to light (recommend sunglasses, don't stay in sun for long periods of time)
d) punctate defects in cornea with too-frequent use
Oral acyclovir treats what disease? What should you take with oral acyclovir for maximum effectiveness?
Herpes zoster
a full glass of water
Acyclovir MOA?
inhibiting DNA replication
Acyclovir shouldn't be taken by patients sensitive to valacyclovir. What are potential adverse effects of Acyclovir?
a) Renal failure, complicate worsen renal function in renal impaired patients
b) CNS: Ecephalopathy/neurotoxicity
c) blood dyscrasias and coagulation problems
e) hepatic complications
f) severe skin reactions
g) visual changes
h) GI disturbances
i) agitation, dizziness, myalgia, parethesias
T/F Patients with renal impairment do not need dose adjustments with Acyclovir.
FALSE
T/F there are many drug-to-drug interactions with acyclovir.
TRUE
__________ is a prodrug for cyclovir
Valacyclovir
Trifluridine 1% ophthalmic solution can cause what adverse effects?
Hyperemia
Epithelial keratopathy
Increased IOP
Dry eye and irritation
Burning/stinging upon installation
Which of the antivirals need to be refrigerated?
Trifluridine 1% ophthalmic solution
Corticosteroids can accelerate the spread of viral infections and are usually contraindicated in treatment of ______________ however, steroids may be used concurrently with trifluridine in treatment of _______________ infections and trifluridine should be continued for a few days after the steroid has been discontinued
superficial Herpes simplex virus keratitis
Herpes simplex stromal infections
Coritcosteroids and anti-infective combinations are sometimes prescribed for what conditions?
Steroid-responsive inflammatory conditions with bacterial infections or risk of bacterial infections
Some anti-infective components that may be used with corticosteroids are...
Sulfacetamide sodium, neomycin/polymyxin, gentamicin, or tobramycin
Possible corticosteroid components of corticosteroid and anti-infective combinations include...
T/F Combination solutions should be shaken vigorously well prior to use
F: they should be shaken but rolling between palms of hands is sufficient otherwise air bubbles can result
T/F steroid containing products may increase IOP
true!
Ampicillin**
aka: Principen, others
Possible regimen: 250-500 mg PO q 6 hr
Comments: Renal dose adjustment needed
Clindamycin**
aka: Cleocin
Possible regimen: 150-450 mg PO q 6 hr
Comments: Hard to tolerate, high potential for serious GI ADEs. Hepatic caution as well
Azithromycin**
aka: Z-Pack, Zithromax, Zmax
- other strength products and preparations available
Possible regimen: For Z-Pack: 2 x 500 mg tabs PO on day 1, then 1 x 250 mg tab PO on days 2-5
Comments: Dose varies by indication.
- Hepatic drug clearance*
Doxyclycline**
aka: Vibramycin, Vibra-tabs, Doryx, others
Possible Regimen: 100 mg PO q 12 hr
Comments: mostly hepatic clearance*
Levofloxacin**
aka: Levaquin
Possible Regimen: 250-750 mg PO q 24 hr
Comments: Renal dose adjustment needed
Moxifloxacin**
aka: Avelox
Possible Regimen: 400 mg PO q 24 hr
Comments: no renal adjustment needed*
Trimethoprim/sulfamethoxazole**
(not specifically on MT2, but on NBEO)
aka: Bactrim DS, Septra DS
- 800 mg SMX/160 mg TMP = "double strength"
Possible Regimen: For CA-MRSA: 2 DS tablets PO B.I.D.
(DS = double strength)
Comments: Renal dose adjustment needed
- Dose varies depending on whether double strength preparation is used
Acyclovir**
aka: Zovirax
Possible Regimen: 800 mg PO 5x per day
Comments: Renal dose adjustment needed
Valacyclovir**********
aka: Valtrex
Possible Regimen: 1000 mg PO T.I.D. for VZV keratitis
Comments: Renal dose adjustment needed
Before prescribing any oral medication, what should you check for?
1) Check for potential drug-to-drug interactions
2) Compare the drug that you are considering prescribing with the other meds on the patient's medication history/profile
3) Seek the assistance of the patients's primary medical doctor and/or a pharmacist if needed to interpret relative risks and for overall patient safety
Class: Centrally acting adrenergic nerve blockers
Representative Drugs:
Clonidine, Guanabenz, Guanfacine, Methyldopa
MOA: α2 agonists, decrease sympathetic outflow from brain to lower blood pressure
Uses: HTN
Other info: orthostatic hypotension, sedation and other possible ADEs possible.
Blurred vision, conjunctivitis, and dry eyes are possible
Class: Diuretics
Representative Drugs: Several in different classes--see diuretics section
Mechanism of action: see diuretics section in syllabus
Uses: hypertension, edema, CHF
Other info: thiazide diuretics currently used as initial meds for HTN
Other info: usually reserved for hypertensive crisis, accelerated HTN, or advanced cases poorly controlled with more than one other class of anti-hypertensive agent.
MOA: Competitive blockade of β adrenergic receptors.
- Some agents are specific for β1 receptors at usual doses, while others have actions on both β1 and β2 receptors
Uses: HTN. Some used also for cardiac arrhythmias, angina pectoris, glaucoma, migraine prophylaxis, MI prevention, CHF maintenance, etc.
Other Info: Many potential SDRs and D:D interactions. Individual agents need to be reviewed carefully when listed on a medication hx. Use of these agents can cause dryness or soreness of the eyes, orthostatic hypotension, etc. Non-selective agents and high doses can exacerbate bronchospasm in asthma or COPD patients.
Class: Calcium channel antagonists
Representative Drugs:Nifedipine, Diltiazem, Verapamil, Isradipine, Amlodipine and others
MOA: Blocks calcium influx during slow channel exchange, dilates peripheral arterioles, some are used for antiarrhythmic properties, also used for angina prophylaxis.