Amox

# Amox (Amoxicillin) ## Overview - **Classification**: Penicillin antibiotic (beta-lactam) - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to bacterial lysis. ## Primary Indications 1. **Acute Otitis Media (AOM)** - Middle ear infection 2. **Streptococcal Pharyngitis** - "Strep throat" 3. **Community-Acquired Pneumonia (CAP)** - Lower respiratory tract infection 4. **Sinusitis** - Sinus infection 5. **Skin and Soft Tissue Infections** - Select non-MRSA infections 6. **H. pylori Eradication** - Part of multi-drug regimens 7. **Dental Prophylaxis** - Prevention of bacterial endocarditis ## Adult Dosing ### Standard Dosing **Acute Otitis Media / Sinusitis / Lower RTI** - **Dose**: **500 mg** to **875 mg** - **Frequency**: Every **8 hours** (500 mg) or every **12 hours** (875 mg) - **Route**: Oral - **Duration**: **5-10 days** (duration varies by indication) **Streptococcal Pharyngitis** - **Dose**: **500 mg** - **Frequency**: Every **12 hours** or **250 mg** every **8 hours** - **Route**: Oral - **Duration**: **10 days** **H. pylori Eradication** - **Dose**: **1 g** (1000 mg) - **Frequency**: Every **12 hours** (as part of multi-drug regimen) - **Route**: Oral - **Duration**: **14 days** **Dental Prophylaxis (for infective endocarditis)** - **Dose**: **2 g** (2000 mg) - **Frequency**: Single dose **30-60 minutes** before procedure - **Route**: Oral ### Dose Adjustments - **Renal Impairment**: Adjust based on creatinine clearance (CrCl) - CrCl **>30 mL/min**: No adjustment needed - CrCl **10-30 mL/min**: **250-500 mg** every **12 hours** - CrCl **<10 mL/min**: **250-500 mg** every **24 hours** - Hemodialysis: Administer during or after dialysis; supplement dose. - **Hepatic Impairment**: Generally **no specific adjustment** needed. Use with caution in severe impairment. - **Elderly Patients**: Adjust primarily based on **renal function**. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **20-30 mg/kg/day** (divided doses) - **Frequency**: Every **12 hours** - **Maximum**: Not clearly defined, but use caution due to immature renal function. - **Special Notes**: Use lowest effective dose. Extended interval due to immature renal function. ### Infants (1-12 months) - **Dose**: **80-90 mg/kg/day** (high-dose for AOM/Sinusitis), or **40-45 mg/kg/day** (standard) - **Frequency**: Divided every **8-12 hours** - **Maximum**: **1000 mg/day** (for high-dose) - **Formulation**: Oral suspension often preferred. ### Children (1-12 years) - **Dose**: **80-90 mg/kg/day** (high-dose for AOM/Sinusitis/CAP) or **40-45 mg/kg/day** (standard dose for pharyngitis, mild infections) - **Frequency**: Divided every **8-12 hours** - **Maximum**: **1750 mg/day** (high-dose) or **1000 mg/day** (standard dose). Do not exceed **adult maximum dose**. - **Formulation**: Oral suspension or chewable tablets. ### Adolescents (13-18 years) - **Dose**: Generally follow **adult dosing** guidelines. - **Frequency**: Based on indication (e.g., every 8 or 12 hours). - **Maximum**: **2000 mg/day** (standard max) up to **3000 mg/day** (e.g., for H. pylori or severe infections). ## Safety Information ### Contraindications - **Absolute**: Documented severe hypersensitivity to amoxicillin or other penicillins. - **Absolute**: Documented history of cholestatic jaundice/hepatic dysfunction associated with amoxicillin. - **Relative**: History of other beta-lactam (e.g., cephalosporin) hypersensitivity reaction. ### Common Adverse Effects - **Very Common (>10%)**: Diarrhea - **Common (1-10%)**: Nausea, vomiting, rash (maculopapular), candidiasis (oral/vaginal) - **Serious but Rare**: Anaphylaxis, Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), Clostridioides difficile-associated diarrhea (CDAD), hepatotoxicity, severe allergic reactions. ### Key Drug Interactions - **Allopurinol**: Increased risk of amoxicillin rash. - **Methotrexate**: Increased methotrexate levels, leading to toxicity. Monitor methotrexate levels closely. - **Oral Anticoagulants (e.g., Warfarin)**: May alter INR. Monitor INR, adjust anticoagulant dose. - **Oral Contraceptives**: Theoretical reduction in efficacy; advise backup method. - **Probenecid**: Increases and prolongs amoxicillin blood levels. Avoid concurrent use if possible. ## Monitoring & Follow-up - **Before Treatment**: Assess for penicillin or beta-lactam allergies. - **During Treatment**: Monitor for signs of allergic reaction (rash, itching, swelling). - Monitor for resolution of infection symptoms. - Monitor for severe diarrhea (may indicate C. diff). - **Clinical Signs**: Watch for new rash, persistent diarrhea, fever, or signs of superinfection (e.g., oral thrush). ## Clinical Pearls - 💡 **Completion is Key**: Advise patients to complete the full course of therapy, even if feeling better. - 💡 **Food Neutral**: Can be taken with or without food. Taking with food may reduce GI upset. - 💡 **Rash Awareness**: A non-allergic rash can occur, especially with viral infections (e.g., mono). Differentiate from allergic reactions. - 💡 **Suspension Storage**: Reconstituted oral suspension requires refrigeration and should be discarded after 14 days. Shake well before each use. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.