Bactrim 80 mg/400 mg per 5 mL Solution for infusion.

Indication

Treatment of bacterial infections including urinary tract infections, respiratory tract infections, and certain gastrointestinal infections.

Dosage (summary)

The usual dosage for adults is 8 to 12 mg/kg/day of trimethoprim and 40 to 60 mg/kg/day of sulfamethoxazole, administered in divided doses.

Onset of Action / Duration

Onset of action typically occurs within 1 to 2 hours, with duration of action lasting approximately 12 hours.

Special Populations

• Renal impairment
• Hepatic impairment
• Elderly patients
• Children under 2 months of age

Pregnancy & Breastfeeding

Use during pregnancy is not recommended, particularly in the first trimester. Caution is advised during lactation as both components are excreted in breast milk.

Key Drug Interactions

• May enhance the effects of anticoagulants such as warfarin.
• Concurrent use with methotrexate may increase the risk of toxicity.
• May reduce the efficacy of oral contraceptives.

Contraindications

• Hypersensitivity to sulfonamides or trimethoprim.
• Severe liver disease.
• Severe renal impairment.
• Pregnancy (especially during the first trimester).

Common side effects

• Nausea and vomiting
• Rash
• Fever
• Hematological reactions (e.g., leukopenia, thrombocytopenia)
• Elevated liver enzymes

Counselling Points

• Take the medication as prescribed and complete the full course.
• Stay hydrated to help prevent kidney complications.
• Report any signs of rash, fever, or unusual bleeding to a healthcare provider immediately.
• Avoid excessive sun exposure and use sunscreen due to increased sensitivity.