You should not take trimethoprim if you:
- are allergic to trimethoprim or any other ingredients included in the medication
- are pregnant
- have severe liver problems
- have any blood disorders such as a particular type of anaemia
Can you take trimethoprim when pregnant?
Trimethoprim is not recommended during pregnancy, especially during the first trimester. That’s because trimethoprim can cause folate deficiency, a nutrient that’s essential for the developing foetus and prevents neural tube defects.
But, it is important to treat UTIs when pregnant. So if you are pregnant, think you might be, or are trying for a baby and require antibiotic treatment, you should tell your doctor.
Can you take trimethoprim while breastfeeding?
Yes, it is thought to be safe to take trimethoprim while breastfeeding because only a tiny amount of the drug passes to the baby in breast milk. If you are worried about the effect of trimethoprim and you are breastfeeding, you should speak to your doctor.
[H3] List of medications that can interact with trimethoprim
Trimethoprim does not mix well with several drugs including:
- diuretics (water tablets) and other high blood pressure drugs
- rifampicin (a type of antibiotic)
- blood thinners such as warfarin
- digoxin (used to treat heart problems)
- some anticonvulsants such as phenytoin (epilepsy medication)
- repaglinide and pioglitazone (to treat diabetes)
- bone marrow depressants
- some malaria tablets
You should tell your doctors if you are taking any medication as it may interact with trimethoprim.
Can you drink alcohol when taking trimethoprim?
Yes, you can drink alcohol when taking trimethoprim.
Can you take paracetamol with trimethoprim?
Yes, it is safe to take paracetamol and ibuprofen when taking trimethoprim.
Does trimethoprim affect the contraceptive pill?
Trimethoprim does not affect how the contraceptive pill works. That means you can continue to take the combined pill, mini pill, or emergency contraceptive pill (if needed) and still be protected from pregnancy, if they are taken correctly.
If trimethoprim makes you sick or causes you to have diarrhoea, then your contraceptive pill may not protect you from pregnancy.
If you are concerned, you should read the patient information leaflet that comes with your pill.
In most cases, if you are sick or have diarrhoea within 2 hours of taking the pill, then it is unlikely it will have been absorbed by your body. If you are sick or have diarrhoea, you must ask your doctor for advice.
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