Co-Amoxiclav

# Co-amoxiclav ## Overview - **Classification**: Beta-lactam antibiotic, Penicillin class, combined with a beta-lactamase inhibitor. - **Mechanism**: Amoxicillin inhibits bacterial cell wall synthesis. Clavulanic acid irreversibly binds to and inactivates beta-lactamase enzymes, protecting amoxicillin from degradation. ## Primary Indications 1. **Respiratory Tract Infections** - Acute bacterial sinusitis, otitis media, community-acquired pneumonia, acute exacerbations of chronic bronchitis. 2. **Skin & Soft Tissue Infections** - Cellulitis, animal/human bites, impetigo, wound infections. 3. **Urinary Tract Infections** - Cystitis, pyelonephritis (complicated and uncomplicated). 4. **Bone & Joint Infections** - Osteomyelitis, septic arthritis. ## Adult Dosing ### Standard Dosing **General Infections (e.g., mild to moderate RTI, Skin/Soft Tissue)** - **Dose**: **500 mg** amoxicillin / **125 mg** clavulanic acid - **Frequency**: Every **8 hours** (TID) - **Route**: Oral - **Duration**: 5-10 days, depending on infection **Severe Infections (e.g., severe RTI, complicated UTI, sinusitis, animal bites)** - **Dose**: **875 mg** amoxicillin / **125 mg** clavulanic acid - **Frequency**: Every **12 hours** (BID) - **Route**: Oral - **Duration**: 7-10 days ### Dose Adjustments - **Renal Impairment**: Dosing based on CrCl: * CrCl >**30 mL/min**: No adjustment. * CrCl **10-30 mL/min**: **250-500 mg** amoxicillin / **125 mg** clavulanic acid every **12 hours**. Max **500/125 mg** BID. * CrCl <**10 mL/min**: **250-500 mg** amoxicillin / **125 mg** clavulanic acid every **24 hours**. * Hemodialysis: Administer during and at the end of dialysis. Max **500/125 mg** every **24 hours**. - **Hepatic Impairment**: Use with caution. Monitor liver function regularly. - **Elderly Patients**: No specific dose adjustment needed based on age alone, but assess renal function. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **30 mg/kg/day** (amoxicillin component) - **Frequency**: Divided every **12 hours** (Q12H) - **Maximum**: Not applicable as mg/kg. Use lower amoxicillin to clavulanic acid ratio (e.g., 4:1 suspension). - **Special Notes**: Consider delayed excretion in neonates. Avoid formulations with high clavulanic acid. ### Infants (1-12 months) - **Dose**: **25-45 mg/kg/day** (amoxicillin component) for mild-moderate infections. Up to **90 mg/kg/day** for severe infections (e.g., otitis media). - **Frequency**: Divided every **12 hours** (BID) or every **8 hours** (TID) - **Maximum**: **125 mg** clavulanic acid per dose. Use 7:1 or 14:1 formulations for higher amoxicillin doses. - **Special Notes**: Use appropriate oral suspension strength (e.g., 200 mg/5 mL, 400 mg/5 mL, 600 mg/5 mL). ### Children (1-12 years) - **Dose**: **25-45 mg/kg/day** (amoxicillin component) for mild-moderate infections. Up to **90 mg/kg/day** for severe infections (e.g., recurrent otitis media). - **Frequency**: Divided every **12 hours** (BID) or every **8 hours** (TID) - **Maximum**: **125 mg** clavulanic acid per dose. Max **875 mg** amoxicillin per dose. - **Special Notes**: Use suspensions (e.g., 400/57 mg/5mL for BID) or chewable tablets. Max clavulanate component should not exceed **10 mg/kg/day**. ### Adolescents (13-18 years) - **Dose**: Generally follows **adult dosing** guidelines. - **Maximum**: Adult maximum dose (e.g., **875 mg** amoxicillin / **125 mg** clavulanic acid BID). ## Safety Information ### Contraindications - **Absolute**: History of severe hypersensitivity to penicillin or other beta-lactam antibiotics (e.g., anaphylaxis). - **Absolute**: History of co-amoxiclav-associated cholestatic jaundice or hepatic dysfunction. - **Absolute**: Infectious mononucleosis (high risk of rash). ### Common Adverse Effects - **Very Common (>10%)**: Diarrhea. - **Common (1-10%)**: Nausea, vomiting, skin rash, mucocutaneous candidiasis. - **Serious but Rare**: Cholestatic jaundice, hepatitis, severe cutaneous adverse reactions (SCARs), Clostridium difficile-associated diarrhea (CDAD), angioedema, anaphylaxis. ### Key Drug Interactions - **Oral Anticoagulants (e.g., Warfarin)**: Increased INR/bleeding risk. Monitor INR closely. - **Methotrexate**: Reduced renal excretion of methotrexate, potentially increasing toxicity. Monitor methotrexate levels. - **Probenecid**: Decreased renal tubular secretion of amoxicillin, increasing amoxicillin levels. - **Allopurinol**: Increased incidence of rash, especially in hyperuricemic patients. - **Oral Contraceptives**: May reduce efficacy (advise additional contraception). ## Monitoring & Follow-up - **Before Treatment**: Assess for penicillin allergy history, liver/kidney function. - **During Treatment**: * Monitor for signs of hypersensitivity (rash, itching, dyspnea). * Observe for severe diarrhea (potential CDAD). * Monitor LFTs if prolonged treatment or history of hepatic impairment. * Monitor renal function in patients with pre-existing impairment. - **Clinical Signs**: Resolution of infection symptoms (fever, pain), improvement in lab markers (e.g., WBC). ## Clinical Pearls - 💡 **Take with food**: To minimize gastrointestinal upset and enhance absorption. - 💡 **Finish the full course**: Even if feeling better, to prevent antibiotic resistance. - 💡 **Suspension storage**: Reconstituted suspension must be stored in the refrigerator and discarded after 7-10 days. - 💡 **Rash in mono**: Avoid use in suspected infectious mononucleosis due to high risk of non-allergic rash. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.