TRIMETHOPRIM

g. uncomplicated bacterial cystitis in women) and two weeks according to the nature and severity of infection. The first dose can be doubled. Adults and children over 12 years: 200mg twice daily. Children 6-12 years: 100mg twice daily.

Children under 6 years of age:

Not recommended; a more suitable dosage form should be used in this age group.

Elderly:

Dosage is dependent upon kidney function; see special dosage schedule.

Long-term treatment and prophylactic therapy:

Adults and children over 12 years: 100mg at night. Children 6-12 years: 50mg at night. Where a single daily dose is required, dosage at bedtime may maximise urinary concentrations. The approximate dosage in children is 2mg trimethoprim per kg body weight per day.

25 Men >600 Women >400 Half the normal dose Trimethoprim is removed by dialysis. However, it should not be administered to dialysis patients unless plasma concentrations can be estimated regularly.

Route of Administration:

For Oral Administration

Gastro-intestinal disturbances including nausea and vomiting, headache, skin rashes, pruritis, urticaria, hyperkalaemia and depression of haematopoiesis have been reported occasionally. Erythema multiforme, Stevens Johnson syndrome, toxic epidermal necrolysis, photosensitivity and other allergic reactions including angioedema, anaphylactic reactions and anaphylactoid reactions have been reported rarely.

Aseptic meningitis has also been reported. Cases of Megaloblastic anaemia during prolonged therapy with Trimethoprim in doses higher than those recommended rarely occur but are reversible with discontinuation of therapy and administration of folinic acid.

Patients with marked impairment of renal function; care should be taken to avoid accumulation and resulting adverse hepatological effects. Regular haematological tests should be undertaken in patients receiving long- term treatment and those pre-disposed to folate deficiency.

The elderly may be more susceptible to folate deficiency and a lower dose may be advisable. Patients and their carers should be told how to recognize signs of blood disorders and advised to seek immediate medical attention if symptoms such as fever, sore throat, rash, mouth ulcers, purpura, bruising or bleeding develop.

Particular care should be exercised in the haematological monitoring of children on long-term therapy. Trimethoprim should be prescribed with caution in patients with porphyria. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

• Trimethoprim hypersensitivity • Severe hepatic insufficiency • Severe renal insufficiency • Megaloblastic anaemia and other blood dyscrasias. Trimethoprim should not be administered to premature infants or children under 4 months of age.

Pregnancy - Trimethoprim should not be administered to pregnant women.