CO-TRIMOXAZOLE = SULFAMETHOXAZOLE (SMX)/TRIMETHOPRIM (TMP) oral

Prescription under medical supervision


Therapeutic action

– Combination of two antibacterials: a sulfonamide (sulfamethoxazole) and a diaminopyrimidine antifolate (trimethoprim)

Indications

– Treatment of cerebral toxoplasmosis, pneumocystosis, isosporiasis, cyclosporiasis and brucellosis
– Prophylaxis of pneumocystosis, toxoplasmosis and isosporiasis
– Second-line treatment of pertussis
– Typhoid fever if the strain is susceptible (recent drug susceptibility test)

Forms and strengths

– 400 mg SMX + 80 mg TMP and 800 mg SMX + 160 mg TMP tablets
– 100 mg SMX + 20 mg TMP dispersible tablet for paediatric use

Dosage

Treatment of cerebral toxoplasmosis
Child > 1 month and adult: 25 mg SMX + 5 mg TMP/kg 2 times daily

Treatment of pneumocystosis
Child > 1 month: 50 mg SMX + 10 mg TMP/kg 2 times daily
Adult: 1600 mg SMX + 320 mg TMP 3 times daily

Treatment of isosporiasis and cyclosporiasis 
Adult: 800 mg SMX + 160 mg TMP 2 times daily

Prophylaxis of pneumocystosis, toxoplasmosis and isosporiasis
Child > 1 month: 50 mg SMX + 10 mg TMP/kg once daily, as long as necessary
Adult: 800 mg SMX + 160 mg TMP once daily, as long as necessary

Treament of pertussis, brucellosis and typhoid fever
Child > 1 month: 20 mg SMX + 4 mg TMP/kg 2 times daily
Adult: 800 mg SMX + 160 mg TMP 2 times daily

Duration

Cerebral toxoplasmosis: 4 to 6 weeks; pneumocystosis: 21 days; isosporiasis: 7 to 10 days; cyclosporiasis, typhoid fever: 7 days; pertussis: 14 days; brucellosis: 6 weeks

Contra-indications, adverse effects, precautions

– Do not administer to children under 1 month.
– Do not administer to sulfonamide-allergic patients; patients with severe renal or hepatic impairment.
– Do not combine with phenytoin (increased plasma concentrations of phenytoin).
– May cause:
• gastrointestinal disturbances, hepatic or renal disorders (crystalluria, etc.), metabolic disorders (hyperkalaemia, hypoglycaemia, hyponatraemia); neuropathy, photosensitivity, haemolytic anaemia in patients with G6PD deficiency;
• allergic reactions (fever, rash, etc.) sometimes severe (Lyell's and Stevens-Johnson syndromes, haematological disorders, etc.); agranulocytosis, megaloblastic anaemia due to folic acid deficiency. In these cases, stop treatment immediately.
– Adverse effects occur more frequently in patients with HIV infection.
– In the event of prolonged treatment, monitor blood count if possible.
– Avoid combination with drugs inducing hyperkalaemia: potassium salts, spironolactone, enalapril, NSAIDs, heparin (increased risk of hyperkalaemia).
– Monitor combination with: zidovudine (increased haematotoxicity), antidiabetics (increased risk of hypoglycaemia).
– Drink plenty of water during treatment to reduce risk of crystalluria.
Pregnancy: avoid using during the first trimester (risk of malformation) and during the last month of pregnancy (risk of neonatal jaundice and haemolytic anaemia).
Breast-feeding: avoid if premature neonate, jaundice, low-birth weight, during the first month of life. If co-trimoxazole is used, observe the child for signs of jaundice.

Remarks

Preferably take during meals.
– Also comes in 200 mg SMX + 40 mg TMP/5 ml oral suspension.
  Storage: below 25 °C -