Ceftriaxone

# Ceftriaxone ## Overview - **Classification**: Third-generation Cephalosporin antibiotic - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to bacterial cell lysis and death. ## Primary Indications 1. **Community-Acquired Pneumonia (CAP)** - Broad-spectrum empiric therapy 2. **Bacterial Meningitis** - High CSF penetration 3. **Skin and Soft Tissue Infections** - Effective against common pathogens 4. **Gonorrhea** - First-line treatment for uncomplicated infections ## Adult Dosing ### Standard Dosing **Severe Infections (e.g., CAP, Pyelonephritis)** - **Dose**: **1-2 g** - **Frequency**: Once daily (every 24 hours) - **Route**: IV or IM - **Duration**: Typically 7-14 days, depending on infection **Bacterial Meningitis** - **Dose**: **2 g** - **Frequency**: Every 12 hours - **Route**: IV - **Duration**: 7-21 days depending on pathogen **Uncomplicated Gonorrhea** - **Dose**: **500 mg** (for patients <150 kg) - **Frequency**: Single dose - **Route**: IM - **Special consideration**: Co-treat with azithromycin 1g PO single dose if Chlamydia not ruled out. ### Dose Adjustments - **Renal Impairment**: No routine adjustment needed for CrCl >10 mL/min. Max **2g/day** for severe impairment (CrCl <10 mL/min) or ESRD. - **Hepatic Impairment**: No routine adjustment needed. - **Elderly Patients**: No specific dose adjustment; monitor for age-related decline in renal function. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **50 mg/kg** - **Frequency**: Once daily (every 24 hours) - **Maximum**: **50 mg/kg/day** - **Special Notes**: **Contraindicated** in hyperbilirubinemic neonates and with IV calcium. May displace bilirubin from albumin. ### Infants (1-12 months) - **Dose**: **50-75 mg/kg** - **Frequency**: Once daily (every 24 hours) - **Maximum**: **2 g/day** (standard) - **Special Notes**: Avoid concurrent IV calcium administration. ### Children (1-12 years) - **Dose**: **50-75 mg/kg** - **Frequency**: Once daily (every 24 hours) - **Maximum**: **2 g/day** (standard) - **Meningitis**: **100 mg/kg/day** (divided q12-24h), Max **4 g/day**. ### Adolescents (13-18 years) - **Dose**: Generally follow adult dosing guidelines. - **Maximum**: Typically **2 g/day** for most infections; **4 g/day** for meningitis or severe infections. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to ceftriaxone or other cephalosporins. - **Absolute**: Neonates (≤28 days) requiring IV calcium-containing solutions. - **Absolute**: Hyperbilirubinemic neonates (especially premature). - **Relative**: History of severe penicillin allergy (e.g., anaphylaxis). ### Common Adverse Effects - **Common (1-10%)**: Diarrhea, rash, injection site pain/tenderness, eosinophilia, thrombocytosis. - **Less Common (0.1-1%)**: Nausea, vomiting, headache, dizziness, increased LFTs. - **Serious but Rare**: Pseudomembranous colitis (C. difficile), hemolytic anemia, biliary pseudolithiasis ("sludge"), Steven-Johnson Syndrome. ### Key Drug Interactions - **Calcium-containing solutions/products**: Risk of fatal precipitation in lungs/kidneys, especially in neonates. **Do not co-administer**. - **Oral Anticoagulants (e.g., Warfarin)**: May increase INR; monitor INR closely. - **Vaccines (e.g., Live Typhoid)**: May decrease vaccine efficacy; administer vaccine at least 24 hours after last dose. ## Monitoring & Follow-up - **Before Treatment**: Obtain culture and sensitivity if possible. Assess renal and hepatic function. - **During Treatment**: Monitor for signs of adverse effects (e.g., diarrhea, rash). Monitor LFTs if prolonged treatment. - **Clinical Signs**: Resolution of fever, improved symptoms, normal WBC count. ## Clinical Pearls - 💡 **Half-life**: Ceftriaxone's long half-life allows for once-daily dosing, improving adherence. - 💡 **Biliary Excretion**: Unique dual elimination (renal & biliary), often no dose adjustment needed in isolated renal or hepatic impairment. - 💡 **Calcium Interaction**: **CRITICAL** to avoid concurrent IV administration with calcium in all ages, especially neonates. Flush lines thoroughly if sequential use is unavoidable. - 💡 **IM Injection**: Can be mixed with lidocaine 1% to reduce injection site pain. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.