Fusidic Acid

Antibiotic Class:

Fusidane

Antimicrobial Spectrum:

Gram-positive: Staphylococcus spp. C. difficile, C. perfringens, Peptostreptococcus spp., Propionibacterium acnes; Gram-negative: Neisseria spp.; Other: Mycobacterium spp.

Mechanism of Action:

Inhibition of protein synthesis via interfering with elongation factor G

Pharmacodynamics:

No data

Pharmacokinetics:

Cmax: 52.4 mg/L; Half-life: 9.8 (hr); Total Clearance: 21 ml/min; Volume of distribution: 0.3 L/kg; Table 2

Adverse Effects:

Hematologic: granulocytopenia, thrombocytopenia

GI: hepatotoxicity, nausea, vomiting, abdominal pain, diarrhea,

Dosage:

Tablets: 250, 500mg

Suspension: 250mg/5ml

IV: 500mg vial

Adults: 250 – 500mg PO or IVq8 to q12 hours

Children: 12mg/kg up to 500mg IV q 12 hours or 20mg/kg/day divided q 8 hours

Disease state based dosing:

Renal failure: Dosing adjustments not necessary

Hepatic failure: No official recommendations exist, but avoidance in patients with severe liver disease may be warranted.

Contraindications/Warnings/Precautions:

Precautions: Use caution in patients with jaundice/hepatic dysfunction

Drug Interactions:

Fusidic acid is metabolized in the liver and CYP 450 enzyme interactions have been reported.

Ritonavir and Saquinavir: inhibition of metabolism and increased fusidic acid levels

Cholestyramine: binds fusidic acid and decreases bioavailability

Pregnancy:

Category C: Risk unknown. Human studies inadequate.

Monitoring Requirements:

Therapeutic: Culture and sensitivities, signs and symptoms of infection

Toxic: LFTs should be monitored in intravenous or prolonged therapy