How To Get Comfortable With Prescription Oral Medications How To

How To Get Comfortable With
Prescription Oral Medications
Jimmy D. Bartlett, O.D., D.Sc., FAAO
Professor Emeritus, The University of Alabama
at Birmingham
American Optometric Association
June 24, 2015
Disclosure Statement
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Alcon
Allergan
Bausch & Lomb
Jobson Medical Publishing
Shire Pharmaceuticals
United States Pharmacopeia
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How To Get Comfortable
Know the disease state you’re treating
Know the applicable drug(s) – not all, just
the few you will be using
 Know your patient and ask the right
questions
 Don’t memorize dosages – look them up
 Clinical experience is key
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Clinical Pearls
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Select your patients carefully
Treat according to your comfort level, or just a little
beyond
As your experience grows, so will your confidence
If possible or practical, spend some time in a
colleague’s office, a “referral center,” or other clinic
where you can gain hands-on experience
Review your cases with a trusted colleague, partner,
or faculty member
Remember that there are many “correct” ways to
treat ocular disease
Importance of Patient History
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Gives clues to drug contraindications!
 Medical
 Hepatic
 Renal
 GI
 Allergies
 Medications, including
OTC
Drug Interactions Causing
Decreased GI Absorption of
Tetracyclines
Avoid milk, dairy, and
antacids
 Formation of drug-drug
complexes (Ca2+, Mg2+)
 Tetracyclines ↔ milk,
dairy, antacids
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ORAL ANTIVIRAL DRUGS
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Ophthalmic Management
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No therapy may
be required
Topical steroids
for corneal edema
and anterior
uveitis
Oral analgesics
Oral Antivirals
Acyclovir
Should be started within 72 hours of skin
lesions, but can be as late as 1 week
 800 mg 5 times daily for 7 days
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Acyclovir Formulations
200 mg capsule
 400 mg tablet
 800 mg tablet
 200 mg/5 ml suspension
(banana flavor)
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Benefits of Acyclovir Therapy
Dendriform
keratopathy
 Stromal keratitis
 Anterior uveitis
 Acute and chronic
pain
 Few side effects
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Valacyclovir (Valtrex)
Prodrug of acyclovir
Available as 500 mg
tablet
 Dosage is 1000 mg
tid x 7 days
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Famciclovir (Famvir)
Prodrug of penciclovir
 Available as 125, 250, 500 mg tablet
 Dosage is 500 mg tid x 7 days
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Side Effect(s) of Antivirals
Nausea
 Diarrhea
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What to Ask Before Prescribing
“Are you allergic to antiviral medications
such as acyclovir (“Zovirax”)?”
 “Have you been treated before with this
medicine and had to stop for any reason?”
 “Are you pregnant or nursing?”– get in the
habit of asking this question unless the
patient is not a female of childbearing
potential
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Don’t Forget These Procedures!
Slit lamp exam
 Uveitis?
 IOP
 Dilated fundus
exam
 Retinitis?
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Acyclovir in Active HSV
Keratitis
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Oral acyclovir 400 mg 5
times daily for treatment of
HSV epithelial keratitis
Does not prevent stromal
disease
Does not benefit stromal
keratitis in patients
receiving topical antivirals
and steroids
Acyclovir in Preventing Recurrent
HSV Keratitis
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Effective preventive dose is 400
mg BID (or Valtrex 500 mg QD)
 Dendritric (epithelial)
 Even effective for disciform
(stromal)
Because of expense, greatest
benefit is in suppression of
vision-threatening stromal
disease
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ORAL ANTIBACTERIAL
DRUGS
Conditions Requiring Oral
Antibacterial Drugs
Preseptal cellulitis
Internal hordeolum
Meibomian gland
dysfunction*
Chlamydial conjunctivitis
Ocular rosacea*
Dacryocystitis
A Good Place To Start is
Preseptal Cellulitis or Internal
Hordeolum
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Eyelid Anatomy
Etiology
Local infection of eyelid or adnexa
Eyelid or facial trauma
 Upper respiratory tract infection
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Be Comfortable With The
Diagnosis– Differentiate From
Orbital Cellulitis
Proptosis
 Visual acuity
 Pupils
 Ocular motility
 Pain and fever
 Constitutional symptoms
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Differentiation From Orbital
Cellulitis
Clinical Finding
Proptosis
Chemosis
Vision
Pupils
Motility
Pain on motion
IOP
Temperature
Preseptal Cellulitis
Absent
Rare
Normal
Normal
Usually normal
Absent
Normal
Usually normal
Orbital Cellulitis
Marked
Common
Often reduced
May be APD
Restricted
Present
May be elevated
Elevated (>102)
General Treatment Strategy
(Adult)
Largely empirical
Penicillinase-resistant penicillin or
 First-generation cephalosporin
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Penicillins
Penicillins Resistant to
Penicillinase (β Lactamase)
Methacillin
 Oxacillin
 Cloxacillin
 Dicloxacillin
 Nafcillin
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Penicillin-ß Lactamase Inhibitor
Combination (Broad Spectrum)
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Amoxicillin/Clavulanate (Augmentin)
 Expensive! (875 mg x 20 = $145)
 Generic is $32-$46
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Augmentin*
Formulation
Amoxicillin
Clavulanic Acid
Tablet
250, 500, 875 mg
125 mg
Chewable Tablet
200, 250, 400 mg
28.5-62.5 mg
Oral Suspension
125, 200, 400 mg
per 5 ml
28.5-62.5 mg
per 5 ml
*All formulations are pregnancy cat. B and probably safe during breastfeeding
Augmentin Formulations
What To Ask Before Prescribing
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“Are you allergic to penicillin or cephalosporin
drugs such as Keflex?”
True allergy signs and symptoms include:
 Hives
 Itching
 Rash
 Acute low blood pressure
 Laryngeal edema/difficult breathing
Upset stomach is not an allergic response
“Are you pregnant or nursing?”
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Cephalosporins
First-Generation Cephalosporins
Name
Formulation
Cephalexin (generic)
Keflex
Cephradine (generic)
Velosef
Cefadroxil (generic)
Duricef
250, 500 cap
250, 500 mg, 1 g tab
125, 250 mg/5ml
250, 500 mg cap
125, 250 mg/5ml
250, 500 mg cap
125, 250 mg/5ml
Second-Generation
Cephalosporins
Name
Cefaclor (generic)
Ceclor, Ceclor CD
Cefprozil (Cefzil)
Cefuroxime (Ceftin)
Formulation
250, 500 mg cap
375, 500 mg tab
125, 250, 375 mg/5ml
250, 500 mg tab
125, 250 mg/5ml
125, 250, 500 mg tab
125, 250 mg/5ml
Loracarbef (Lorabid) 200, 400 mg cap/100, 200 mg/5ml
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Ceftin Formulations
As You Go From 1st to 2nd to 3rd
You increase gram-negative coverage
 You lose gram-positive coverage
 You increase cost astronomically!
 So use 1st generation cephalosporins for
adults and children with presumed staph
infection
 Use 2nd generation for children with URIs
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Allergic Reactions to β-Lactam
Antibiotics
Prevalence of penicillin allergy is only 2%
Avoid penicillin in patients with history of
severe PCN allergy
 Acute low blood pressure
 Extensive hives, swelling, itching
 Laryngeal edema
 Patients with mild PCN reactions can
usually be given a cephalosporin
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Macrolides
Azithromycin Formulations
Formulation
Strength
Cost
Tablet
250, 600 mg
Oral Suspension*
100, 200 mg/5ml
2 g/60 ml (single dose)
Z-Pak
250 mg tablets (6)
$26
Tri-Pak
500 mg tablets (3)
$44
*Take at least 1 hr before or 2 hr after meals
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What To Ask Before Prescribing
“Are you allergic to “mycin” drugs?”
 “Did you have to stop treatment with a
“mycin” drug for any reason?”
 “Are you pregnant?”
 Avoid clarithromycin in pregnancy
(category C)
 Azithromycin and erythromycin are
cat. B
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Antibiotic Combinations
Trimethoprim/Sulfamethoxazole
Trimethoprim/Sulfamethoxazole
Name
Formulation
80 mg trim/400 mg sulf
Trimethoprim/sulfamethoxazole 160/800 mg (double
strength)
(generic)
40/200 mg/5ml
Bactrim, Bactrim DS
Cotrim, Cotrim DS
Septra, Septra DS
Same as above
Bactrim is a Sulfonamide!
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Sulfonamide (“Sulfa”) Allergy
“Sulfur” is not a sulfonamide
 “Sulfites” are not sulfonamides
 “Sulfates” are not sulfonamides
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ACNE ROSACEA AND MEIBOMIAN
GLAND DYSFUNCTION (MGD)
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Acne Rosacea
Tetracyclines
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Here We Use Tetracyclines As
Antiinflammatories, Not
Antimicrobials
Inhibit lipase activity of normal lid flora
Inhibit matrix metalloproteinases (MMPs)
and other inflammatory mediators
 Anticollagenase properties
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Antilipase Activity and Matrix
Metalloproteinase (MMP-9)
Inhibition
Typical Response
To Treatment
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Prescription for Doxycycline
06/24/15
Doxycycline 50 mg
# 60
Sig.: Take one PO BID for
ocular rosacea
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Side Effects of Tetracyclines
Nausea, diarrhea, pseudomembranous
colitis
 For nausea, administer with food
 Tooth discoloration, bone deformity
 Photosensitization
 Esophagitis (do not take within 1 hr of
bedtime)
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Side Effects of Oral
Antibacterials
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Side Effects of Antibacterials
Hypersensitivity reactions
 GI irritant effects
 Nausea, diarrhea
 Pseudomembranous colitis
 Vaginal candidiasis
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Vaginal Candidiasis
Treat with oral
fluconazole (Diflucan)
 150 mg PO x 1(single
oral dose)
 1-2 yogurts/day
 Antifungal creams
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PRESCRIBING DURING
PREGNANCY
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Drug Use During Pregnancy
FDA
Category
Clinical
Implication
A
No risk to fetus
Levothyroxine, vitamin B6
C
No evidence of
risk
Risk cannot be
ruled out
Azithromycin, erythromycin,
dicloxacillin, cephalexin
Clarithromycin, ciprofloxacin,
methylprednisolone dose pack
D
X
Risk to fetus
Definite risk!
Tetracycline, doxycycline
Misoprostol, isotretinoin
B
Example
PRESCRIBING FOR
CHILDREN
Pediatric Dosage Calculation*
Clark’s Rule
Pediatric Dose = Adult Dose x Weight (kg)
70
or
Adult Dose x Weight (lb)
150
*5 ml = 1 tsp
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Pediatric Dosage Calculation
By Age
Age
Percent of Adult Dose
>12
100%
6-12
50%
2-6
25%
Pediatric Azithromycin Example
For FDA-Approved Dosage
6 year-old female
Weighs 40 lb
 Recent URI
 Presents with red, swollen, painful RUL
 Dosage is 10mg/kg x 1d, then 5mg/kg x 4d
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Pediatric Azithromycin Example
Amanda Jane Doe
6
06/24/15
Zithromax 200mg/5 ml
Sig.: One tsp PO on first day, then onehalf tsp QD x 4 days for eye infection.
Take 1 h ac or 2 h pc
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Reread Your Prescription for
Accuracy!
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