Ceftriaxone

Ceftriaxone (INN) (pronounced /ˌsɛftraɪˈæksoʊn/, /ˌkɛf-/) is a third-generation cephalosporin antibiotic. Like other third-generation cephalosporins, it has broad spectrum activity against Gram positive and Gram negative bacteria. In most cases, it is considered to be equivalent to cefotaxime in terms of safety and efficacy. Ceftriaxone sodium is marketed by Hoffman-La Roche under the trade name Rocephin.

Additional recommended knowledge

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Clinical use

Main article: Cephalosporin

Ceftriaxone is often used (in combination, but not direct, with macrolide and/or aminoglycoside antibiotics) for the treatment of community-acquired pneumonia. It is also a choice drug for treatment of bacterial meningitis. In pediatrics, it is commonly used in febrile infants between 4 and 8 weeks of age who are admitted to the hospital to exclude sepsis. It has also been used in the treatment of Lyme disease and gonorrhea.

The usual starting dose is 1 gram IV daily although dosage may be adjusted for body mass in younger patients. Doses range from 1–2 grams IV or IM every 12–24 hours, depending on the type and severity or the infection, up to 4 grams daily. For gonorrhoea the usual adult dose is a single intramuscular injection of 125 mg. Patients treated for gonorrhoea are usually also treated for chlamydia, often with azithromycin. Ceftriaxone is contraindicated in patients with known allergy to the cephalosporin class of antibiotics.

It must not be mixed or adminestered simultaneously (within 48 hours) with calcium-containing solutions or products, even via different infusion lines (rare fatal cases of calcium-ceftriaxone precipitates in lung and kidneys in neonates have been described).

Chemistry

Ceftriaxone is a yellowish-orange crystalline powder which is readily-soluble in water, sparingly soluble in methanol and very slightly soluble in ethanol. The pH of a 1% aqueous solution is approximately 6.7.

The syn-configuration of the methoxyimino moiety confers stability to β-lactamase enzymes produced by many Gram-negative bacteria. Such stability to β-lactamases increases the activity of ceftriaxone against otherwise resistant Gram-negative bacteria. In place of the easily hydrolysed acetyl group of cefotaxime, ceftriaxone has a metabolically-stable thiotriazinedione moiety.

References

1. Ceftriaxone package insert