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Urinary tract infection (lower) - women - Management
What adverse effects are associated with trimethoprim?
- Trimethoprim is generally well tolerated.
- Nausea, vomiting, pruritus, and skin rashes have occasionally been reported. These are generally mild and reversible when trimethoprim is withdrawn.
- Severe adverse drug reactions with trimethoprim are rare.
- There have been rare reports of trimethoprim causing haematological adverse effects, including [Aronson, 2006c]:
- Macrocytic and megaloblastic anaemia: this is more likely in people with pre-existing folate deficiency.
- Agranulocytosis — very rare. In people where leukocytes are monitored regularly, mild leukopenia has been reported in 0.4–10% of people taking trimethoprim or co-trimoxazole (trimethoprim plus sulfamethoxazole).
- Aplastic anaemia, neutropenia, thrombocytopenia, and pancytopenia.
- For people receiving long-term trimethoprim treatment, the British National Formulary advises that they should be warned to seek immediate medical attention if they develop signs of blood disorders such as fever, sore throat, rash, mouth ulcers, purpura, bruising, or bleeding [BNF 57, 2009].
[Aronson, 2006c; Actavis, 2007]
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