FUSIBACT B CREAM (Each 15g tube contains Fusidic acid/ Betamethasone Valerate 2%w/w/ 0.1%w/w)

Indications

• Allergic reactions
• Dermatologic conditions
• Endocrine disorders (such as adrenal insufficiency)
• Gastrointestinal diseases (such as Crohn's disease)
• Hematologic disorders (such as thrombocytopenic purpura)
• Neoplastic diseases (as part of cancer therapy)
• Nervous system disorders (such as multiple sclerosis exacerbations)
• Ocular diseases (such as uveitis)

Mechanism of action

Bethamethasone exerts its effects by binding to the glucocorticoid receptor, which is a type of nuclear receptor. Upon binding, the receptor-ligand complex translocates to the nucleus and influences gene expression. This leads to the upregulation of anti-inflammatory proteins and the downregulation of pro-inflammatory cytokines. As a result, bethamethasone reduces inflammation and modulates the immune response.

Pharmacodynamics

The pharmacodynamic effects of bethamethasone include significant anti-inflammatory, immunosuppressive, and anti-proliferative actions. It decreases the production of inflammatory mediators such as prostaglandins and leukotrienes, thereby alleviating symptoms associated with inflammation. The drug also inhibits the migration of leukocytes to sites of inflammation, which further contributes to its anti-inflammatory effects.

Pharmacokinetics

Bethamethasone is well-absorbed following oral administration, with a bioavailability that can vary based on the route of administration. It is extensively metabolized in the liver, primarily through conjugation with glucuronic acid, and has an elimination half-life of several hours to a day. The drug is excreted predominantly in the urine as metabolites. Its effects can last longer than the half-life due to the sustained action within tissues.

Contra-indications

• Systemic fungal infections
• Hypersensitivity to bethamethasone or any component of the formulation
• Administration of live vaccines in immunocompromised patients

Adverse effects

• Increased susceptibility to infections
• Weight gain
• Fluid retention
• Hypertension
• Hyperglycemia
• Osteoporosis
• Gastrointestinal perforation
• Mood changes
• Cushing's syndrome

Interactions

• Non-steroidal anti-inflammatory drugs (NSAIDs) may increase the risk of gastrointestinal adverse effects
• Antidiabetic agents may require adjustment due to altered glucose metabolism
• Live vaccines may be less effective or cause disease in immunocompromised patients

Precautions

• Use with caution in patients with diabetes, hypertension, or peptic ulcer disease
• Monitor for signs of infection due to immunosuppression
• Gradual withdrawal is necessary to avoid adrenal insufficiency after long-term therapy

Pregnancy

Bethamethasone is categorized as a pregnancy category C drug. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Bethamethasone is excreted in breast milk. Caution should be exercised when administered to a nursing mother.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Tablets
• Injectable solution
• Topical cream
• Topical ointment
• Topical lotion

Indications

• Bacterial skin infections
• Impetigo
• Infected dermatitis
• Osteomyelitis
• Endocarditis

Dosage

Children: Refer to BNF for Children for appropriate dosing recommendations.

Adults: Refer to specific guidelines for dosing based on the condition being treated.

Mechanism of action

Fusidic acid exerts its antibacterial effect by inhibiting bacterial protein synthesis. It binds to the elongation factor G (EF-G) in bacteria, preventing the translocation step during protein synthesis. This action effectively halts the production of proteins necessary for bacterial growth, leading to cell death.

Pharmacodynamics

Fusidic acid demonstrates time-dependent killing against susceptible bacteria. Its antibacterial spectrum includes gram-positive organisms, especially staphylococci. The drug's efficacy is influenced by the concentration at the site of infection and the duration of exposure, with higher concentrations generally leading to greater antibacterial activity.

Pharmacokinetics

Fusidic acid is well absorbed when administered orally, with peak plasma concentrations occurring within one to two hours. It is extensively protein-bound, primarily to albumin. The drug is metabolized in the liver and has a relatively long half-life of approximately 6 to 8 hours, allowing for less frequent dosing. The majority of the drug is excreted in the bile, with a minor amount appearing in the urine.

Contra-indications

• Hypersensitivity to fusidic acid or any of its components
• Severe liver impairment

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Rash
• Hepatotoxicity
• Jaundice
• Thrombocytopenia

Interactions

• May interact with anticoagulants such as warfarin, enhancing their effects
• Co-administration with statins may increase the risk of myopathy
• Potential interaction with cyclosporine, leading to increased plasma levels of cyclosporine

Precautions

• Use with caution in patients with liver disease
• Monitor liver function tests in prolonged therapy
• Evaluate for signs of allergic reactions
• Consider the potential for drug interactions, particularly with hepatic enzyme inducers or inhibitors

Pregnancy

Fusidic acid is classified as category C. It should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Fusidic acid is excreted in breast milk. Caution is advised when administering to breastfeeding mothers.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Topical cream
• Topical ointment
• Oral tablets
• Intravenous injection