Meropenum

# Meropenum ## Overview - **Classification**: Carbapenem antibiotic - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to bacterial cell lysis. ## Primary Indications 1. **Complicated Intra-abdominal Infections (cIAI)** - Including peritonitis and appendicitis with rupture. 2. **Complicated Skin and Skin Structure Infections (cSSSI)** - Such as cellulitis, diabetic foot infections. 3. **Bacterial Meningitis** - For susceptible strains, including in pediatric patients. 4. **Hospital-Acquired Pneumonia (HAP)** - Including ventilator-associated pneumonia (VAP). 5. **Complicated Urinary Tract Infections (cUTI)** - Including pyelonephritis. 6. **Febrile Neutropenia** - Empiric therapy for presumed bacterial infections. ## Adult Dosing ### Standard Dosing **Complicated Intra-abdominal Infections (cIAI), Complicated Skin and Skin Structure Infections (cSSSI), Complicated Urinary Tract Infections (cUTI), Hospital-Acquired Pneumonia (HAP), Febrile Neutropenia** - **Dose**: **1 gram** - **Frequency**: Every **8 hours** - **Route**: Intravenous (IV) infusion over 15-30 minutes - **Duration**: 5-14 days, dependent on infection type and severity. **Bacterial Meningitis** - **Dose**: **2 grams** - **Frequency**: Every **8 hours** - **Route**: Intravenous (IV) infusion over 15-30 minutes - **Duration**: 7-21 days, dependent on pathogen and clinical response. ### Dose Adjustments - **Renal Impairment**: - CrCl 26-50 mL/min: Standard dose every **12 hours**. - CrCl 10-25 mL/min: Standard dose every **24 hours**. - CrCl <10 mL/min (including hemodialysis): Standard dose every **24 hours**, administer after dialysis. - **Hepatic Impairment**: No specific dose adjustment recommended. - **Elderly Patients**: Adjust dose based on renal function; monitor for adverse effects. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **20 mg/kg** - **Frequency**: Every **12 hours** (0-7 days) or every **8 hours** (8-28 days) - **Maximum**: Do not exceed adult doses; follow weight-based dosing. - **Special Notes**: Administer as IV infusion over 15-30 minutes. Limited data in extremely low birth weight neonates. ### Infants (1-12 months) - **Dose**: **20 mg/kg** - **Frequency**: Every **8 hours** - **Maximum**: **1 gram** per dose. - **Special Notes**: For meningitis or severe infections, consider **40 mg/kg** every 8 hours. ### Children (1-12 years) - **Dose**: **20 mg/kg** - **Frequency**: Every **8 hours** - **Maximum**: **1 gram** per dose for most infections. - **Special Notes**: For meningitis or severe infections, consider **40 mg/kg** every 8 hours, maximum **2 grams** per dose. ### Adolescents (13-18 years) - **Dose**: Follow **adult dosing guidelines** based on indication. - **Maximum**: Up to **2 grams** per dose, maximum **6 grams/day**. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to meropenem or other carbapenems. - **Absolute**: Severe hypersensitivity (e.g., anaphylaxis, severe skin reactions) to any beta-lactam antibiotic. ### Common Adverse Effects - **Very Common (>10%)**: Diarrhea, Nausea/Vomiting, Headache. - **Common (1-10%)**: Rash, Pruritus, Injection site reactions, Thrombocytopenia. - **Serious but Rare**: Seizures (especially in renal impairment or CNS disease), Pseudomembranous colitis (C. difficile), Anaphylaxis, Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN). ### Key Drug Interactions - **Valproic Acid/Divaproex**: Meropenem significantly decreases valproate levels, risking loss of seizure control. - **Clinical Significance**: **Avoid concomitant use** if possible. If required, monitor valproate levels closely; consider alternative antiepileptics. - **Probenecid**: Inhibits renal excretion of meropenem, increasing meropenem concentrations. - **Clinical Significance**: Not typically recommended; if used, reduce meropenem dose by 50%. - **Oral Anticoagulants (e.g., Warfarin)**: May enhance anticoagulant effect. - **Monitoring**: Monitor INR/PT closely during co-administration. ## Monitoring & Follow-up - **Before Treatment**: Obtain cultures and susceptibility tests (if feasible), assess renal function (CrCl). - **During Treatment**: Monitor clinical response to therapy, kidney function (especially with impaired function), CBC (for prolonged courses), and signs of C. difficile infection. - **Clinical Signs**: Watch for new onset rash, seizures, or severe/bloody diarrhea. ## Clinical Pearls - 💡 **Tip 1**: Meropenem provides broad-spectrum coverage, including many multidrug-resistant Gram-negative bacteria like Pseudomonas aeruginosa and ESBL-producing organisms. - 💡 **Tip 2**: For critically ill patients or difficult-to-treat infections, extended infusion (e.g., over 3 hours) may optimize therapeutic outcomes. - 💡 **Tip 3**: Counsel patients to report any severe or persistent diarrhea, as it could indicate Clostridioides difficile infection. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.