indication

For the treatment of bacterial infections.

pharmacology

Fusidic acid is a bacteriostatic antibiotic that is often used topically in creams and eyedrops, but may also be given systemically as tablets or injections.

mechanism of action

Fusidic acid works by interfering with bacterial protein synthesis, specifically by preventing the translocation of the elongation factor G (EF-G) from the ribosome. It also can inhibit chloramphenicol acetyltransferase enzymes.

biotransformation

Metabolites include dicarboxylic ester/acid, 3-keto fusidic acid, hydroxy fusidic acid, glucuronide fusidic acid and a glycol metabolite.

absorption

Sodium fusidic acid tablets have a 91% oral bioavailability. Absorption of the film-coated tablets is complete when compared to a solution, however oral absorption is variable. Oral fusidic acid hemihydrate (suspension) achieved a 22.5% bioavailability in pediatric patients following a 20 milligram/kilogram dose.

half life

Approximately 5 to 6 hours in adults.

drug interactions

Amprenavir: The protease inhibitor, amprenavir, may increase the effect and toxicity of fusidic acid.

Atorvastatin: Increased risk of myopathy/rhabdomyolysis

Fosamprenavir: The protease inhibitor, fosamprenavir, may increase the effect and toxicity of fusidic acid.

Indinavir: Indinavir may increase the effect and toxicity of fusidic acid.

Nelfinavir: The protease inhibitor, nelfinavir, may increase the effect and toxicity of fusidic acid.

Penicillin V: Fusidic acid may diminish the therapeutic effect of penicillins. To management this interaction, penicillin should be administered 2 hours before fusidic acid.

Ritonavir: The protease inhibitor, ritonavir, may increase the effect and toxicity of fusidic acid.

Saquinavir: The protease inhibitor, saquinavir, may increase the effect and toxicity of fusidic acid.

Simvastatin: Increased risk of myopathy/rhabdomyolysis

Ticarcillin: Fusidic acid may reduce the effect of Ticarcillin by inhibiting bacterial growth. Ticarcillin exerts its effects on actively growing bacteria. To achieve synergism, Ticarcillin should be administered at least 2 hours prior to using Fusidic acid.

Tipranavir: Concomitant therapy of Tipranavir with Fusidic acid may result in increased serum concentrations of both agents. Consider alternate therapy or monitor for increased serum concentrations and toxocity of both agents.