5. Pharmacological properties
5.1 Pharmacodynamic properties
Fusidic acid and its salts are potent anti-staphylococcal agents with unusual ability to penetrate tissue. Bactericidal levels have been assayed in bone and necrotic tissue. Concentrations of 0.03 - 0.12 micrograms/ml inhibit nearly all strains of Staphylococcus aureus. Fusidic acid is active against Staphylococcus epidermidis and methicillin resistant staphylococci.

In severe or deep seated infections and when prolonged therapy may be required, systemic administration of this product should generally be given concurrently with other anti-staphylococcal antibiotic therapy.

5.2 Pharmacokinetic properties
500 mg of sodium fusidate given as a single infusion over 2 hours results in a Cmax of 52 micrograms/ml. Blood levels are cumulative, reaching concentrations of 60-120 micrograms/ml after repeated infusion of 500 mg sodium fusidate every 8 hours for 2-3 days.

The plasma half-life is approximately 10-15 hours.

This product is excreted mainly in the bile, little or none being excreted in the urine.
5.3 Preclinical safety data
There are no pre-clinical data of relevance to the prescriber which are additional to that already included in other sections of the SPC.

6. Pharmaceutical particulars
6.1 List of excipients
The vial of 10 ml sterile phosphate-citrate buffer solution (pH 7.4 - 7.6) contains disodium hydrogen phosphate, citric acid, disodium edetate and water for injections. (When reconstituted with powder vial contains 3.1 mMol sodium and 1.1 mMol phosphate).

6.2 Incompatibilities
Sodium fusidate reconstituted at 50 mg/ml in buffer solution is physically incompatible with infusion fluids containing 20% or more of dextrose, lipid infusions and peritoneal dialysis fluids. Precipitation may occur at dilutions which result in a pH of less than 7.4.

6.3 Shelf life
3 years for the sodium fusidate dry powder.

After the sodium fusidate dry powder is dissolved in the buffer solution provided and added to 500ml of infusion fluid, the shelf-life of this solution is 24 hours.

6.4 Special precautions for storage
The sodium fusidate dry powder is stable for 3 years when stored at room temperature (below 25°C) and protected from light. When the buffer solution is transferred to the powder vial, this vial should be regarded as a unit dose. The required amount of the sodium fusidate/buffer solution should be used once only and any unused portion discarded.

6.5 Nature and contents of container
Pack containing a single pair of vials; one glass vial of sodium fusidate closed with a butyl rubber stopper secured with metal rings and one glass vial of sterile buffer solution 10 ml closed with a bromobutyl rubber stopper secured with metal