Fb3 WSP

Indications

• Bacterial infections in poultry
• Respiratory infections in livestock
• Enteric infections in animals

Dosage

Children: Refer to the BNF for Children for pediatric dosing information as it varies based on age and weight.

Adults: Refer to specific guidelines for dosing based on the type of infection and the animal species being treated. Consult the BNF for appropriate dosing regimens.

Mechanism of action

Sulfachloropyrazine works by inhibiting bacterial dihydropteroate synthase, an enzyme involved in the synthesis of folate. By blocking this enzyme, sulfachloropyrazine prevents the formation of folate, which is essential for bacterial growth and replication. This mechanism leads to bacteriostatic effects, meaning it halts bacterial growth rather than killing bacteria directly.

Pharmacodynamics

The pharmacodynamic profile of sulfachloropyrazine reveals its role as a competitive inhibitor of para-aminobenzoic acid (PABA), which is a substrate for dihydropteroate synthase. By competing with PABA, sulfachloropyrazine effectively reduces the production of dihydrofolate, which is crucial for nucleic acid synthesis in bacteria. This results in an inhibition of bacterial growth, making it suitable for treating infections caused by susceptible organisms.

Pharmacokinetics

Sulfachloropyrazine is generally well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within a few hours of oral administration. The drug is metabolized in the liver, and its metabolites are excreted primarily via the kidneys. The elimination half-life can vary, and factors such as hydration status and renal function may influence the drug's clearance from the body.

Contra-indications

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

Adverse effects

• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Skin reactions (rash, urticaria, photosensitivity)
• Hematological reactions (aplastic anemia, leukopenia, thrombocytopenia)
• Renal toxicity (interstitial nephritis)
• Hepatic toxicity (hepatitis, cholestatic jaundice)

Interactions

• May potentiate the effects of anticoagulants
• May interfere with the effectiveness of oral contraceptives
• Increased risk of nephrotoxicity when used with other nephrotoxic agents

Precautions

• Monitor renal function during treatment
• Use with caution in patients with liver disease
• Discontinue at the first sign of skin rash or other hypersensitivity reactions
• Ensure adequate hydration to prevent crystalluria

Pregnancy

Use during pregnancy only if the benefits outweigh the risks. Sulfonamides may cause kernicterus in the newborn if used near term.

Breast-feeding

Use with caution, as sulfonamides are excreted in breast milk. Monitor the infant for potential adverse effects.

Storage

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

Formulations

• Tablets
• Powder for oral suspension