fusidic acid: clinical use

Prescribing considerations

• Confirm organism susceptibility; topical treatment is unsuitable for non-susceptible organisms, particularly Pseudomonas aeruginosa.
• Limit extended or recurrent exposure where possible because resistance and topical sensitisation can develop.
• Review concurrent medicines before systemic treatment, particularly statins, anticoagulants, hepatotoxic medicines and CYP3A4 substrates.
• Seek microbiology input for severe, deep-seated or difficult-to-treat staphylococcal infection.

Contraindications and cautions

• Hypersensitivity to fusidic acid, sodium fusidate or formulation excipients.
• Systemic fusidic acid must not be co-administered with statins.
• The selected intravenous product must not be given intramuscularly or subcutaneously or infused in whole blood or amino-acid solutions.
• The oral suspension is unsuitable for certain inherited sugar-intolerance or malabsorption disorders because of its excipients.

Monitoring

• Monitor liver function during systemic treatment when hepatic dysfunction, biliary obstruction, potentially hepatotoxic medicines or extended exposure are relevant.
• Closely monitor anticoagulation when systemic treatment is started or stopped in someone taking an oral anticoagulant.
• Investigate muscle pain, weakness or tenderness promptly and check for statin exposure.
• During intravenous administration, monitor the venous access site and liver-related laboratory results.

Clinical pharmacology

Fusidic acid is a highly protein-bound, predominantly biliary-excreted antistaphylococcal antibiotic. It inhibits bacterial translation by stabilising elongation factor G on the ribosome.

Formulation and product differences

• Cream is for cutaneous use and contains excipients that can cause local contact reactions or irritate eyes and mucous membranes.
• Oral suspension must be shaken and contains glucose, sorbitol, sucrose-containing flavouring, sodium and benzyl alcohol, which may matter in selected patients.
• The intravenous presentation requires careful reconstitution and dilution. The selected product is listed by eMC as discontinued.
• Topical exposure is low; oral and intravenous formulations carry clinically important interaction, hepatic and severe skin-reaction risks.

Cream

Route: Cutaneous

Strengths: 20 mg/g