Ceftriaxone

A powerful injectable third-generation cephalosporin antibiotic.

What is Ceftriaxone?

Ceftriaxone is a third-generation cephalosporin antibiotic administered by injection to treat severe and life-threatening bacterial infections.

It has a long half-life, allowing once-daily dosing in many cases.

History & Background

Ceftriaxone became widely used in hospitals due to its strong antibacterial activity, long duration of action, and effectiveness against resistant organisms.

Chemical Structure & Properties

• IUPAC name: (6R,7R)-7-[(2Z)-2-(2-aminothiazol-4-yl)-2-(methoxyimino)acetamido]-3-[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-1,2,4-triazin-3-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
• Molecular formula: C₁₈H₁₈N₈O₇S₃
• Molar mass: 554.58 g/mol
• Functional groups: Beta-lactam ring, thiazole, triazine

Mechanism of Action

Ceftriaxone kills bacteria by:

• Inhibiting bacterial cell wall synthesis
• Binding to penicillin-binding proteins
• Causing bacterial cell lysis (bactericidal)

Pharmacokinetics

• Administration: Intramuscular (IM) or Intravenous (IV)
• Peak plasma time: 2–3 hours
• Half-life: 6–9 hours
• Protein binding: High (~85–95%)
• Excretion: Urine and bile

Medical Uses

• Severe pneumonia
• Meningitis
• Typhoid fever
• Sepsis
• Gonorrhea (single-dose therapy)

Dosage Guidelines

Adults: 1–2 g once daily (IV/IM)

Severe infections: Up to 4 g/day

⚠️ Administered only under medical supervision.

Side Effects

• Pain at injection site
• Diarrhea
• Allergic reactions
• Biliary sludge (rare)

Warnings & Precautions

• Do not mix with calcium-containing IV solutions in neonates
• Use caution in penicillin allergy
• Monitor liver and kidney function in long-term use

Drug Interactions

• Calcium-containing IV solutions
• Anticoagulants

Frequently Asked Questions

Is ceftriaxone very strong? – Yes.

Is it oral? – No, injectable only.

Is it safe? – Yes, under supervision.

Why is it widely used in hospitals? – Broad coverage and long action.

⚠️ Educational content only. Not a substitute for professional medical advice.