Mox

# Mox (Amoxicillin) ## Overview - **Classification**: Penicillin antibiotic, Beta-lactam. - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to bacterial cell lysis. ## Primary Indications 1. **Acute Otitis Media (AOM)** - Bacterial ear infection. 2. **Streptococcal Pharyngitis** - "Strep throat" (Group A Streptococcus). 3. **Lower Respiratory Tract Infections** - Including community-acquired pneumonia. 4. **Skin and Skin Structure Infections** - Uncomplicated bacterial infections. 5. **Helicobacter pylori Eradication** - Part of multi-drug regimens. ## Adult Dosing ### Standard Dosing **Acute Otitis Media, Sinusitis, Lower Respiratory Tract Infections** - **Dose**: **500 mg** to **875 mg** - **Frequency**: Every 8 hours (TID) or Every 12 hours (BID) - **Route**: Oral - **Duration**: 7-10 days **Streptococcal Pharyngitis** - **Dose**: **500 mg** - **Frequency**: Every 12 hours (BID) OR **250 mg** every 8 hours (TID) - **Route**: Oral - **Duration**: 10 days **H. pylori Eradication** (part of multi-drug therapy) - **Dose**: **1000 mg** - **Frequency**: Every 12 hours (BID) - **Route**: Oral - **Duration**: 7-14 days ### Dose Adjustments - **Renal Impairment**: - **CrCl 10-30 mL/min**: Max dose **500 mg** every 12 hours. - **CrCl <10 mL/min**: Max dose **500 mg** every 24 hours. - **Hemodialysis**: Max dose **500 mg** every 24 hours; administer dose after dialysis. - **Hepatic Impairment**: No specific dose adjustment generally required. - **Elderly Patients**: Adjust based on renal function; no specific age-related adjustment. ## Pediatric Dosing ### Neonates (0-28 days) - **Indication**: Limited use, generally not first-line. - **Dose**: **20-50 mg/kg/day** - **Frequency**: Divided every 12 hours (BID) - **Maximum**: Use with caution, not well-established for this age. - **Special Notes**: Monitor renal function; oral suspension. ### Infants (1-12 months) - **Acute Otitis Media (AOM), Sinusitis (high-dose)**: - **Dose**: **80-90 mg/kg/day** - **Frequency**: Divided every 12 hours (BID) - **Maximum**: **1000 mg/dose** or **2000 mg/day**. - **Formulation**: Oral suspension. - **Mild-Moderate Infections**: - **Dose**: **25-50 mg/kg/day** - **Frequency**: Divided every 8-12 hours (BID-TID) - **Maximum**: **1000 mg/day**. ### Children (1-12 years) - **Acute Otitis Media (AOM), Sinusitis, Severe Infections**: - **Dose**: **80-90 mg/kg/day** - **Frequency**: Divided every 12 hours (BID) - **Maximum**: **1000 mg/dose** or **2000-3000 mg/day**. - **Streptococcal Pharyngitis, Mild-Moderate Infections**: - **Dose**: **25-50 mg/kg/day** - **Frequency**: Divided every 8-12 hours (BID-TID) - **Maximum**: **1000 mg/day**. ### Adolescents (13-18 years) - **Dose**: Generally follow **adult dosing** recommendations. - **Maximum**: **2000-3000 mg/day** (standard); up to **4000 mg/day** for severe infections. ## Safety Information ### Contraindications - **Absolute**: History of severe hypersensitivity reaction to penicillin (e.g., anaphylaxis, Stevens-Johnson syndrome). - **Absolute**: History of cholestatic jaundice/hepatic dysfunction associated with amoxicillin/clavulanate. - **Relative**: Mononucleosis (high risk of non-allergic rash). ### Common Adverse Effects - **Very Common (>10%)**: Diarrhea, Nausea. - **Common (1-10%)**: Rash (maculopapular), Vomiting, Abdominal pain, Headache. - **Serious but Rare**: Anaphylaxis, Stevens-Johnson syndrome (SJS), Toxic epidermal necrolysis (TEN), Clostridioides difficile-associated diarrhea (CDAD), Angioedema, Interstitial nephritis, Agranulocytosis. ### Key Drug Interactions - **Methotrexate**: Amoxicillin may decrease renal clearance, increasing methotrexate levels and toxicity. **Monitor methotrexate levels**. - **Warfarin**: May enhance anticoagulant effect by altering gut flora; increased INR. **Monitor INR closely**. - **Oral Contraceptives**: May decrease efficacy (clinical significance debated). **Advise backup contraception**. - **Allopurinol**: Increased incidence of rash. ## Monitoring & Follow-up - **Before Treatment**: Assess for penicillin allergy history. - **During Treatment**: Monitor for signs of allergic reaction (rash, itching, swelling), GI upset. - **Clinical Signs**: Resolution of infection symptoms. Monitor for severe diarrhea (CDAD). - **Long-term/High-dose**: Renal function (CrCl). ## Clinical Pearls - 💡 **Suspension Stability**: Oral suspension is stable for **14 days** when refrigerated. - 💡 **Food Intake**: Can be taken **with or without food**; taking with food may reduce GI upset. - 💡 **Mononucleosis Risk**: Avoid in patients with suspected mononucleosis due to high risk of non-allergic rash. - 💡 **Not for Beta-Lactamase Producers**: Amoxicillin is inactivated by beta-lactamase enzymes; not effective against resistant strains. - 💡 **"Mox" vs. "Augmentin"**: Amoxicillin (Mox) is **not** the same as amoxicillin/clavulanate (Augmentin); Augmentin contains clavulanate for beta-lactamase inhibition. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.