What is the recommended dose of ceftriaxone (a third-generation cephalosporin antibiotic)?

Recommended Dosage of Ceftriaxone

The recommended dose of ceftriaxone for adults is typically 1-2 grams given once daily (or in equally divided doses twice a day) depending on the type and severity of infection, with a maximum daily dose of 4 grams. 1

Adult Dosing by Indication

Standard Adult Dosing

• General infections: 1-2 grams IV/IM once daily 1
• Maximum daily dose: 4 grams 1

Specific Indications

• Uncomplicated gonorrhea: 500 mg IM as a single dose 2
• Disseminated gonococcal infection: 1 gram IV/IM every 24 hours 3
• Gonococcal conjunctivitis: 1 gram IM as a single dose 3
• Bacterial meningitis: 2 grams IV every 12 hours (total 4 grams/day) 2
• Infective endocarditis: 2 grams IV every 12 hours or 4 grams once daily 3
• Surgical prophylaxis: 1 gram IV 30-120 minutes before surgery 1

Pediatric Dosing

• Skin/soft tissue infections: 50-75 mg/kg/day IV/IM once daily (maximum 2 grams) 1
• Acute otitis media: 50 mg/kg IM as a single dose (maximum 1 gram) 1
• Serious non-meningeal infections: 50-75 mg/kg/day divided every 12 hours (maximum 2 grams) 1
• Meningitis: 100 mg/kg loading dose (maximum 4 grams), then 100 mg/kg/day once daily or divided every 12 hours (maximum 4 grams/day) 1
• Infants 8-28 days old with UTI or bacteremia: 50 mg/kg IV/IM every 24 hours 3
• Infants 29-60 days old with UTI or bacteremia: 50 mg/kg IV/IM every 24 hours 3

Administration Methods

Intramuscular Administration

• Reconstitute with appropriate diluent to achieve concentration of 250-350 mg/mL 1
• Inject into a relatively large muscle; aspiration helps avoid inadvertent intravascular injection 1

Intravenous Administration

• Administer by infusion over 30 minutes 1
• For neonates, administer over 60 minutes to reduce risk of bilirubin encephalopathy 1
• Recommended concentrations: 10-40 mg/mL 1

Special Considerations

Renal/Hepatic Impairment

• No dosage adjustment necessary for patients with renal or hepatic impairment 1
• Even in patients with creatinine clearance <15 mL/min, plasma concentrations remain therapeutic with standard dosing 4

Elderly Patients

• No modification required for elderly patients up to 2 grams per day, provided there is no severe renal or hepatic impairment 1

Pregnancy

• Ceftriaxone is considered safe in pregnancy; preferred over fluoroquinolones or tetracyclines 3
• Women who cannot tolerate cephalosporins should be administered spectinomycin 2 g IM 3

Important Compatibility Issues

• Do not use diluents containing calcium (e.g., Ringer's solution or Hartmann's solution) to reconstitute ceftriaxone 1
• Incompatible with vancomycin, amsacrine, aminoglycosides, and fluconazole in admixtures 1
• When administering these drugs concomitantly, give sequentially with thorough flushing of IV lines between administrations 1

Duration of Therapy

• General infections: 4-14 days; longer therapy may be required for complicated infections 1
• Streptococcal infections: At least 10 days 1
• Bacterial meningitis: 7-14 days 2
• Infective endocarditis: 4-6 weeks 2

Common Pitfalls to Avoid

1. Underdosing for severe infections, particularly meningitis and endocarditis
2. Failing to adjust infusion time for neonates (should be 60 minutes)
3. Mixing with calcium-containing solutions, which can cause precipitation
4. Not considering once-daily dosing when appropriate, which is more convenient and equally effective for most infections 5
5. Inadequate duration of therapy, particularly for streptococcal infections

The long half-life of ceftriaxone (7.6-8.3 hours) allows for once-daily dosing in most cases, which is a significant advantage over many other antibiotics 5. Recent evidence suggests that for bacteremia, there is no significant difference in clinical outcomes between 1 gram and 2 gram daily dosing 6, though the higher dose is still recommended for severe infections.