From the Guidelines
Fusidic acid is an antibiotic medication primarily used to treat bacterial infections, particularly those caused by Staphylococcus bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). It works by inhibiting bacterial protein synthesis by preventing the elongation factor G from releasing from the ribosome, thereby stopping bacteria from multiplying. Fusidic acid is available in various formulations including oral tablets, eye drops, and topical creams or ointments. For skin infections, it's typically applied as a 2% cream or ointment 3-4 times daily for 7-10 days. For systemic infections, oral fusidic acid is usually dosed at 500mg three times daily for adults, as recommended in the guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections 1. Due to rapid development of resistance, fusidic acid is often combined with other antibiotics for serious infections, such as rifampicin, as suggested in the management of fracture-related infection 1. Common side effects include gastrointestinal disturbances when taken orally and skin irritation when applied topically. It should be used with caution in patients with liver disease as it's primarily metabolized by the liver.
Some key points to consider when using fusidic acid include:
- The importance of combining fusidic acid with other antibiotics to prevent resistance, as highlighted in the guidelines for the diagnosis and treatment of diabetic foot infections 1.
- The need to select dosages of antibiotic agents according to recommendations of the FDA, as stated in the practice guidelines for the diagnosis and management of skin and soft tissue infections 1.
- The potential for fusidic acid to be used in combination with other antibiotics, such as rifampicin, for the treatment of serious infections, as suggested in the guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections 1.
- The importance of monitoring for side effects, such as gastrointestinal disturbances and skin irritation, when using fusidic acid, as noted in the guidelines for the diagnosis and treatment of diabetic foot infections 1.
Overall, fusidic acid is a valuable antibiotic for the treatment of bacterial infections, particularly those caused by Staphylococcus bacteria, including MRSA. However, it should be used judiciously and in combination with other antibiotics to prevent resistance, as recommended in the guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections 1 and the management of fracture-related infection 1.
From the Research
Definition and Mechanism of Action
- Fusidic acid is an oral antistaphylococcal antibiotic that inhibits protein synthesis by binding to EF-G-GDP, resulting in the inhibition of both peptide translocation and ribosome disassembly 2.
- It is a steroidal antibiotic and the only marketed member of the fusidane class, with a novel structure and mode of action, resulting in little cross-resistance with other known antibiotics 2.
Uses and Efficacy
- Fusidic acid has been used to treat skin infections, as well as chronic bone and joint infections, and has demonstrated efficacy against Staphylococcus aureus, including methicillin-resistant strains 3, 4, 5.
- It has been shown to be effective in the treatment of acute osteomyelitis, chronic osteomyelitis, septic arthritis, and prosthetic and other device-related infections 4, 5.
- However, clinical efficacy against methicillin-resistant Staphylococcus aureus (MRSA) has been demonstrated in small studies and case reports, particularly when used in combination with other antibiotics 6.
Resistance and Dosage
- Resistance to fusidic acid can occur through mutations in the FusA gene or the acquisition of genes that code for small proteins that protect EF-G-GDP from binding fusidic acid 2.
- A new dosing regimen has been developed, consisting of a front-loading dose to decrease the potential for resistance development, followed by a maintenance dose, which is being used in clinical trials in the United States for skin and refractory bone and joint infections 2.