Prescribing Oral Antibacterial and Antiviral Drugs

Transcription

1 Prescribing Oral Antibacterial and Antiviral Drugs Disclosure Statement Jimmy D. Bartlett, O.D., F.A.A.O. President, Pharmakon Group Birmingham, Alabama Alcon Allergan Bausch & Lomb Pharmaceuticals ISTA Pharmaceuticals Pharmakon Vision Service Plan Please silence all mobile devices. Unauthorized recording of this session is prohibited. Prescriptive Authority for Oral Medications in Optometry Oral Antiviral Drugs 1

2 Herpes Zoster Ophthalmicus Etiology Recurrent varicella-zoster virus Occurs most often in immunocompromised patients Physical and emotional trauma, immunosuppressive medications, irradiation, cancer, TB, and HIV can reactivate the virus Diagnosis of HZO in patients younger than 45 years warrants testing for HIV Diagnosis Headache, malaise, fever, chills Followed in one or two days by neuralgic pain Followed in 2 or 3 days by hot, hyperesthesia and edema of dermatomes Unilateral vesicular eruption Vesicles become yellow and turbid and form eschars by day

3 Treatment of Skin Lesions Avoid drying lotions Oral antihistamines may prevent itching Warm solution of aluminum acetate (Burow s) Oculoplastic consultation Ophthalmic Management No therapy may be required Topical steroids for corneal edema and anterior uveitis Oral analgesics Acyclovir Should be started within 72 hours of skin lesions 800 mg 5 times daily for 7-10 days Acyclovir s 200 mg capsule 400 mg tablet 800 mg tablet 200 mg/5 ml suspension (banana flavor) 3

4 Benefits of Acyclovir Therapy Dendriform keratopathy Stromal keratitis Anterior uveitis Acute and chronic pain Valacyclovir (Valtrex) Prodrug of acyclovir Available as 500 mg tablet Dosage is 1000 mg tid x 7 days Famciclovir (Famvir) Prodrug of penciclovir Available as 125, 250, 500 mg tablet Dosage is 500 mg tid x 7 days 4

5 Antiviral Cost Comparison (For 7-day course of therapy) Zovirax ($178) Acyclovir ($26) Valtrex ($160) Famvir ($147) Side Effects of Antivirals Malaise (same frequency as placebo) Nausea (less than placebo) Headache (less than placebo) Vomiting (same frequency as placebo) Diarrhea Constipation (less than placebo) Contraindications Hypersensitivity Intolerance Treatment of Immunosuppressed Patients IV acyclovir 30 mg/kg/day for 7 days Long-term prophylactic therapy with oral acyclovir to reduce risk of ARNS Herpes Zoster Neuralgia Postherpetic Neuralgic Pain Varies from minor tingling and numbness to excruciating pain Postherpetic ti neuralgia 5

6 Postherpetic Neuralgic Pain Not For Use In The Eye! Opioid or nonopioid analgesics Tricyclic antidepressants Antianxiety agents Anticonvulsants Capsaicin Cream (Zostrix) When to Add Orals to Topical Therapy of HSV Keratitis When topicals are not effective Primary HSV infection Patient is immunocompromised Infants and children Uveitis not responsive to topical steroids Prophylaxis of recurrence Acyclovir in Active HSV Keratitis 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 Viroptic and steroids Probably beneficial for HSV anterior uveitis when added to topical Viroptic and steroids Acyclovir in Preventing Recurrent HSV Keratitis 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 Also effective in PK to reduce recurrence rate and corneal graft failure Oral Antibacterial Drugs 6

7 Oral Antibacterial Drugs Preseptal Cellulitis Internal Hordeolum M ib i i i * Meibomianitis* Chlamydial Conjunctivitis Ocular Rosacea* Dacryocystitis Dacryocystitis Preseptal Cellulitis 7

8 Eyelid Anatomy Etiology Local infection of eyelid or adnexa Eyelid or facial trauma Upper respiratory tract infection Local Infection S. aureus or ß-hemolytic streptococci Impetigo caused by S. aureus or group A S. pyogenes Erysipelas caused by group A S. pyogenes Human or Animal Bites Anaerobes such as Peptostreptococcus and Bacteroides sp. Foul-smelling discharge, necrotic tissue, gas in tissue, or severe toxemia 8

9 Upper Respiratory Tract Infection In children under age 6 years, usually caused by H. influenzae type B or S. pneumoniae In older children and adults, usually caused by streptococci and S. aureus Primary focus is nasopharynx, sinuses or middle ear Serious H. influenzae infection occurs in children under age 2 Confirm or exclude H. influenzae type B vaccination Differentiation from Orbital Cellulitis Proptosis Visual acuity Pupils Ocular motility Pain and fever Constitutional symptoms 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 Orbital Cellulitis Marked Common Often reduced May be APD Restricted Present May be elevated Usually normal Elevated (>102 ) Examination Puncture wounds, trauma, infectious lesions Facial tenderness, nasal discharge are signs of sinusitis Medial canthal tenderness and tearing indicate dacryocystitis Examination (cont d) Order CT if eyelids cannot be separated WBC and blood culture (young children) Culture skin lesions Lumbar puncture if meningeal signs are present H. influenzae preseptal cellulitis has sharply demarcated, dark-purple discoloration 9

10 General Treatment Strategy Largely empirical Penicillinase-resistant penicillin or First-generation cephalosporin Penicillins Pharmacology Thiazolidine ring ß-lactam ring Bactericidal effect Classified by antibacterial spectra Penicillins Effective Against Gram-Positive Bacteria Penicillin G (parenteral) Penicillin V (oral) 10

11 Penicillin V (Oral) Penicillin V Is Not Effective Against Staph! Name Penicillin VK (generic) Beepen-VK Pen-Vee K 250, 500 mg tab 125, 250 mg/5ml Veetids Penicillins Resistant to Penicillinase (β Lactamase) Methacillin Oxacillin Cloxacillin Dicloxacillin Nafcillin Cloxicillin Name Cloxicillin Sodium (generic) Cloxapen 250, 500 mg cap 125 mg/5ml Dicloxicillin Name Dicloxicillin Sodium (generic) Pathocil 250, 500 mg cap 62.5 mg/5ml Dynapen 11

12 Penicillins with Extended Spectra of Activity Ampicillin Amoxicillin Destroyed by penicillinase ß-Lactamase Inhibitors Potassium clavulanate Sodium sulbactam Penicillin-ß Lactamase Inhibitor Combinations Amoxicillin/Clavulanate (Augmentin) Expensive! (875 mg x 20 = $145) Generic is $32-$46$46 Ampicillin/Sulbactam (Unasyn) Ticarcillin/Clavulanate (Timentin) 12

13 Augmentin Augmentin s Amoxicillin Clavulanic Acid Tablet Chewable Tablet 250, 500, 875 mg 125 mg 200, 250, 400 mg mg Oral Suspension 125, 200, 400 mg per 5 ml mg per 5 ml Penicillins with Anti-Pseudomonal Activity Carbenicillin Mezlocillin Piperacillin Ticarcillin Side Effects Hypersensitivity reactions (2 %) Irritant effects Hyperkalemia or hypokalemia Nausea, vomiting, diarrhea Pseudomembranous colitis Vaginal candidiasis Vaginal Candidiasis Contraindications Treat with oral fluconazole (Diflucan) 150 mg PO x 1(single oral dose) 1-2 yogurts/day Allergy to any penicillin, cephalosporin, or carbapenem New research may modify our approach to penicillin allergy 13

14 Lack of PCN Resensitization in Patients with PCN Allergy Cephalosporins Solensky R, et al. Arch Intern Med 2002; 162: Classification First generation Second generation Third generation First-Generation Cephalosporins Effective against gram-positive bacteria Limited gram-negative coverage Used for surgical prophylaxis and bacterial corneal ulcers (cefazolin), internal hordeolum, preseptal cellulitis First-Generation Cephalosporins First-Generation Cephalosporins Name 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 14

15 Duricef Dosage 500 mg po b.i.d mg po q.d. Second-Generation Cephalosporins More active against gram-negative bacteria May be useful as secondary therapy of internal hordeolum and preseptal cellulitis Second-Generation Cephalosporins Name Cefaclor (generic) Ceclor, Ceclor CD Cefprozil (Cefzil) Cefuroxime (Ceftin) 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 Ceftin s Three Generations Macrolides Erythromycin Clarithromycin (Biaxin) Azithromycin (Zithromax) 15

16 Erythromycin Available as topical and oral formulations Various oral formulations are therapeutically equivalent (avoid estolate in adults) Which Erythromycin is Best? Erythromycin Base Erythromycin Estolate Name Name Erythromycin Base (generic) E-Mycin Ery-Tab 250 mg cap 250, 500 mg enteric-coated coated tab Erythromycin Estolate (generic) Ilosone 250 mg cap 125, 250 mg/5ml 500 mg tab 250 mg cap 125, 250 mg/5ml Erythromycin Stearate Erythromycin Ethylsuccinate Name Name Erythromycin Stearate (generic) Erythrocin Stearate 250, 500 mg film-coated tab 250, 500 mg film-coated tab Erythromycin 400 mg tab Ethylsuccinate t (generic) EryPed E.E.S 400 E.E.S. 200, E.E.S. 400 EryPed Drops 200, 400 mg/5ml 200 mg chewable tab 400 mg tab 200, 400 mg/5ml 100 mg/2.5ml 16

17 Clarithromycin (Biaxin) 6-0-methyl derivative of erythromycin Stable in gastric acid BID dosing Active against H. influenzae Extremely active against Chlamydia Azithromycin (Zithromax) Rapid absorption QD dosing More active than erythromycin against gram-negative bacteria Chlamydial conjunctivitis (single one-gram dose) Azithromycin s Tablet Oral Suspension* Strength 250, 600 mg 100, 200 mg/5ml 2 g/60 ml (single dose) Cost 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 17

18 Contraindications to Macrolides Hypersensitivity Intolerance Avoid clarithromycin in pregnancy (category C) Trimethoprim/Sulfamethoxazole Antibiotic Combinations Trimethoprim/Sulfamethoxazole Name Trimethoprim/sulfamethoxazole i l (generic) Bactrim, Bactrim DS Cotrim, Cotrim DS Septra, Septra DS 80 mg trim/400 mg sulf 160/800 mg (double strength) 40/200 mg/5ml Same as above Case Report 35 year-old WF Internal hordeolum, right upper lid Severe allergy to penicillin Erythromycin upsets stomach Can t swallow pills 18

19 Patients Who Can t Swallow Pills Alternatives to Oral Tablets and Capsules Chewables Suspensions Solutions Elixirs Syrups Liquids Suppositories What s Your Diagnosis? 19

20 Clinical Features Acne Rosacea Macules Papules Pustules Affects skin of cheeks, nose, forehead Teleangiectasia Women most often affected Tetracyclines 20

21 Pharmacology Antilipase Activity Active against gram-positive, gram- negative and Chlamydia Divided pharmacokinetically into 3 groups based on duration of action Inhibit lipase activity of normal lid flora Inhibit matrix metalloproteinases and other inflammatory mediators Anticollagenase properties Oracea TM 20 mg doxycycline hyclate Oracea TM Case Report Doxycycline capsules 40 mg 30 mg immediate release 10 mg delayed release beads Indicated d for treatment t t of inflammatory lesions (papules and pustules) of rosacea in adult patients Dosage is one capsule once daily in AM, 1 hr before or 2 hr after breakfast Has not been evaluated as antibacterial for treatment of infections 21

22 New Management Azelaic acid gel 15% (Finacea ) Elewski BE, Fleischer AB Jr, Pariser DM. A comparison of 15% azelaic acid gel and 0.75% metronidazole gel in the topical treatment of papulopustular rosacea: results of a randomized trial. Arch Dermatol 2003; 39: H. pylori eradication Azelaic Acid Gel 15% (Finacea ) Prescription for Doxycycline Doxycycline 50 mg # 60 Sig.: Take one PO BID for ocular rosacea 3 Adult Inclusion (Chlamydial) Conjunctivitis Management (Current CDC Recommendations) Azithromycin 1 g PO as single dose or Doxycycline yy 100 mg PO BID x 7 d For pregnant/lactating women Erythromycin base 500 mg QID x 7 d or Amoxicillin 500 mg TID x 7 d Comanage with gynecologist or urologist 22

23 Side Effects of Tetracyclines Nausea, vomiting, diarrhea, pseudomembranous colitis For N&V, administer with food Tooth discoloration, bone deformity Liver toxicity Kidney toxicity Photosensitization Esophagitis (do not take within 1 hr of bedtime) Vestibular reactions Dizziness, vertigo with doxy dosages above 100 mg Low-Dose Tetracyclines for Eyelid Disease Meibomianitis + Anterior Blepharitis Cleeravue-M Convenience Kit Minocycline HCl 50 mg SteriLid Eyelid Cleanser Alodox Convenience Kit Doxycycline hyclate 20 mg OcuSoft Lid Scrub Original OcuSoft Lid Scrub Plus Extra Strength 23