Ceftriaxone is a third-generation, broad-spectrum cephalosporin antibiotic with potent bactericidal activity against a wide range of Gram-positive and Gram-negative bacteria. It is characterized by a long plasma half-life, allowing for once or twice-daily dosing. It is highly resistant to beta-lactamases and achieves excellent penetration into body tissues and fluids, including the cerebrospinal fluid (CSF). In the Indian context, it is a critical workhorse antibiotic for severe community-acquired and hospital-acquired infections, though its use is increasingly guided by antimicrobial stewardship programs due to rising resistance.
Adult: 1 to 2 grams once every 24 hours IV or IM. For life-threatening infections (e.g., meningitis), 2 grams every 12 hours. Maximum daily dose is 4 grams.
Note: For IV use: Reconstitute 1gm vial with 10 mL of Sterile Water for Injection. For IM use: Reconstitute with 1% Lidocaine Hydrochloride injection (without epinephrine) to reduce pain. Administer IV infusion over 30 minutes. IM injections should be deep into a large muscle mass (gluteus maximus). NEVER MIX WITH CALCIUM-CONTAINING SOLUTIONS (e.g., Ringer's Lactate) in the same IV line or container, especially in neonates.
Ceftriaxone is a bactericidal beta-lactam antibiotic. It inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs) located on the inner membrane of the bacterial cell wall. This binding inhibits the final transpeptidation step of peptidoglycan synthesis, leading to the formation of a defective cell wall and osmotic lysis of the bacterium.
Pregnancy: Pregnancy Category B. Animal studies have shown no direct harm to the fetus. Ceftriaxone crosses the placenta. Should be used during pregnancy only if clearly needed. Considered a safe option for treating serious bacterial infections in pregnancy.
Driving: Unlikely to affect driving ability. However, patients experiencing side effects like dizziness should avoid driving or operating machinery.
| Warfarin and other Vitamin K Antagonists | Ceftriaxone may potentiate anticoagulant effect by reducing vitamin K-producing gut flora and possibly direct interference. Increased risk of bleeding. | Major |
| Aminoglycosides (e.g., Gentamicin) | Synergistic antibacterial effect against some organisms (e.g., Pseudomonas). However, increased risk of nephrotoxicity, though ceftriaxone itself is low-risk. | Moderate |
| Probenecid | Does NOT significantly increase ceftriaxone levels (unlike other cephalosporins) due to its dual excretion. No interaction expected. | None |
| Calcium-containing IV solutions (Ringer's Lactate, Parenteral Nutrition) | Risk of precipitation of ceftriaxone-calcium salt, particularly in the lungs and kidneys of neonates. CONTRAINDICATED in neonates. Use with caution in others; do not co-administer via same IV line. | Major |
| Chloramphenicol | In vitro antagonism; clinical significance is uncertain. Generally avoided in combination. | Moderate |