Recommended Frequency and Dose of Intramuscular (IM) Ceftriaxone
For adults, the recommended dose of intramuscular ceftriaxone is 1-2 grams given once daily (every 24 hours) for most infections, with specific dosing based on infection type and severity. 1, 2
Adult Dosing Guidelines
- Standard adult daily dose is 1-2 grams given once daily, depending on infection type and severity 1
- For uncomplicated gonococcal infections, a single intramuscular dose of 250mg is sufficient 1, 2
- For disseminated gonococcal infection (DGI), ceftriaxone 1 gram IM every 24 hours is recommended, continuing for 24-48 hours after improvement begins 1
- For severe infections such as bacterial meningitis, higher and more frequent dosing may be required (2 grams every 12 hours) 1
- After reconstitution for IM administration, each 1 mL of solution contains approximately 250-350 mg of ceftriaxone depending on the amount of diluent used 2
Pediatric Dosing Guidelines
- For neonates: postnatal age ≤7 days, 50 mg/kg/day given every 24 hours; postnatal age >7 days and ≤2000 g, 50 mg/kg/day given every 24 hours; postnatal age >7 days and >2000 g, 50–75 mg/kg/day given every 24 hours 3
- For infants and children: 50–75 mg/kg/day divided every 12–24 hours 3
- For pediatric skin and skin structure infections: 50-75 mg/kg once daily (not to exceed 2 grams) 2
- For pediatric meningitis: initial dose of 100 mg/kg (not to exceed 4 grams), followed by 100 mg/kg/day (not to exceed 4 grams daily) 2
Administration Considerations
- Ceftriaxone should be injected well within the body of a relatively large muscle; aspiration helps avoid unintentional injection into a blood vessel 2
- For IM administration, reconstitute with appropriate diluent to achieve concentrations of 250-350 mg/mL 2
- Ceftriaxone is rapidly and completely absorbed following intramuscular administration 4
- After IM injection of 1 gram, mean peak plasma concentrations reach approximately 81 μg/mL 5
- The plasma half-life after IM injection is approximately 8.3 hours 5
Special Considerations
- No dosage adjustment is necessary for patients with impairment of renal or hepatic function, up to 2 grams per day 2
- For ceftriaxone-resistant strains, higher doses and twice-daily dosing may be required 1
- Treatment failures have been reported with lower doses (250-500 mg), particularly for pharyngeal infections 1
- A 2-gram once-daily dose will likely provide therapeutic exposure for patients with creatinine clearance ≤140 mL/min 6
- For patients with high creatinine clearance (≥122 mL/min), standard dosing may be insufficient for pathogens with MIC of 4 mg/L or higher 7
Contraindications
- Should not be used in hyperbilirubinemic neonates 3
- Contraindicated in premature neonates and neonates (≤28 days) if they require calcium-containing IV solutions 2
Ceftriaxone's long half-life (5.8-8.7 hours) allows for convenient once-daily dosing in most clinical scenarios, making it an effective and practical choice for intramuscular antibiotic therapy 4, 8.