FB3 WSP

Indications

• Bacterial infections
• Urinary tract infections
• Respiratory tract infections
• Skin and soft tissue infections

Dosage

Children: Refer to BNF for Children for specific pediatric dosing recommendations.

Adults: Refer to specific guidelines for dosing; typical adult dosages range based on the severity and type of infection.

Mechanism of action

Sulphachloropyrazine acts by competitively inhibiting the enzyme dihydropteroate synthase, which is involved in the bacterial folate synthesis pathway. This inhibition prevents the formation of dihydropteroic acid, a precursor to folate, thus impeding bacterial growth and replication.

Pharmacodynamics

The drug demonstrates bactericidal activity through its action on the bacterial folate synthesis pathway. It is particularly effective against certain strains of Escherichia coli, Streptococcus, and Staphylococcus, among others. The efficacy of sulphachloropyrazine can be influenced by the presence of pus and necrotic tissue, which may sequester the drug and reduce its effectiveness.

Pharmacokinetics

Sulphachloropyrazine is well absorbed from the gastrointestinal tract. It is metabolized in the liver and excreted primarily via the kidneys. The elimination half-life may vary, and renal function can significantly influence the drug's clearance and dosing requirements. It is important to monitor renal function in patients receiving this medication.

Contra-indications

• Hypersensitivity to sulfonamides or any component of the formulation
• Severe renal impairment
• Porphyria
• Blood dyscrasias

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Rash
• Hematological reactions such as agranulocytosis, aplastic anemia
• Hypersensitivity reactions including Stevens-Johnson syndrome
• Renal impairment

Interactions

• May enhance the effects of anticoagulants
• May reduce the effectiveness of oral contraceptives
• Potential interaction with methotrexate leading to increased toxicity
• May interact with other drugs that are highly protein-bound

Precautions

• Use with caution in patients with a history of renal disease
• Monitor for signs of blood dyscrasias
• Adequate hydration should be maintained to prevent crystalluria
• Use with caution in elderly patients

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Not recommended during breastfeeding due to potential adverse effects on the infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Tablets containing 500 mg of sulphachloropyrazine