Co-trimoxazole

Type of Medication: Antibiotic

Indications: treatment of Burkholderia cepacia, Achromobacter, S.maltophilia, H influenza, MSSA, prophylaxis  and treatment of PCP, Mycobacterium abscessus infection

Side Effects: Nausea, rash (including Stevens Johnson syndrome,toxic epidermal necrolysis, photosensitivity), blood disorders (including leucopenia, neutropenia, thrombocytopenia, agranulocytosis, megaloblastic anaemia, haemolytic anaemia), raised bilirubin and transaminases, convulsions, ataxia, vertigo, tinnitus, arthralgia, myalgia, glossitis, stomatitis, anorexia,hepatic necrosis, pancreatitis, antibiotic associated colitis, eosinophilia, cough, pulmonary infiltrates, aseptic meningitis, headaches, crystalluria, renal disorders(maintain adequate fluid intake).

Route of administration: Adult (Oral)

Dose: Standard therapy 960mg bd (1.44 g in severe infection) for 10 to 14 days. Prophylaxis of PCP: 960 mg once daily (may be reduced to 480 mg to improve tolerance) or 960 mg on alternative days (3 times a week) or 960 mg BD on alternative days (3 times a week).

Administration: Available as 240 and 480 mg in 5 ml syrup or suspension. 480 mg and 960 mg tablets

Route of administration: Adult (Intravenous)

Adults: 1.44 g twice daily.

Route of administration: Paediatric (Oral)

Dose: children: doses of 10–20 mg of trimethoprim/kg/dose twice daily have been used. 6 weeks to 5 months – 120 mg bd, 6 months to 5 yrs -240 mg bd, 6 to 12 yrs 480 mg bd. May be increased by 50% in severe infection. Prophylaxis of PCP: 6 weeks – 5 months 120 mg twice a day on 3 consecutive days or 7 days per week; 6 months – 5 years 240 mg; 6-12 years 480 mg

Route of administration: Paediatric (Intravenous)

Dose: children: doses of 10–20 mg of trimethoprim/kg/dose twice daily have been used

Examples of some Drug Interactions

Interacting drug: Amiodarone – increased risk of ventricular arrhythmias

Interacting drug: Cyclosporin – renal impairment

Interacting drug: Methotrexate – increased antifolate effect

Interacting drug: Phenytoin – antifolate effect increased also phenytoin level increased.

Interacting drug: Sulphonylureas – antidiabetic effect enhanced

Interacting drug: Warfarin – increases INR