How does trimethoprim work?
Trimethoprim blocks an enzyme bacteria need to make DNA, stopping them from multiplying and helping the body’s immune system fight the infection.
What is trimethoprim used to treat?
Trimethoprim is commonly prescribed for:
- Urinary tract infections (UTIs)
- Chest infections (as part of combination treatments)
- Preventing recurrent UTIs
- Other bacterial infections as advised by a doctor
Who can take trimethoprim?
Trimethoprim is suitable for most adults and children, but your doctor will determine if it’s right for you.
Who might not be able to take trimethoprim?
Trimethoprim may not be suitable if you:
- Have kidney disease (your dose may need adjusting)
- Have a folate deficiency (low folic acid levels)
- Are pregnant, especially in the first trimester
- Have had an allergic reaction to trimethoprim or similar antibiotics
Can I take trimethoprim if I’m pregnant or breastfeeding?
Trimethoprim isn’t usually recommended during early pregnancy, as it may affect folic acid levels. If you are breastfeeding, small amounts may pass into breast milk, so speak to your doctor before taking it.
What if I miss a dose?
If you forget a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed one—do not take two doses at once.
How effective is trimethoprim?
Trimethoprim is highly effective for treating UTIs and other bacterial infections when taken as prescribed.
What should I do if I take too much?
Taking too much trimethoprim may cause nausea, vomiting, headaches, or confusion. If you think you’ve taken too much, seek medical advice immediately.
What dose of trimethoprim is usually taken?
- For UTIs: 200mg twice daily for 3 to 7 days
- For recurrent UTIs: 100mg once daily for prevention
Your doctor will determine the best dose based on your condition.
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What are the side effects of trimethoprim?
Common side effects include:
Serious side effects, such as severe allergic reactions, mouth ulcers, or jaundice, require urgent medical attention.
How should I take trimethoprim?
Trimethoprim is taken as tablets or liquid, usually twice daily. It should be swallowed whole with water.
When should trimethoprim be taken?
Trimethoprim can be taken with or without food, at evenly spaced times throughout the day.
What are the brand names for trimethoprim?
Trimethoprim is available as a generic medicine, but some branded versions include:
- Monotrim
Final thoughts
Trimethoprim is an effective antibiotic for treating UTIs and other bacterial infections. To get the best results, take it as prescribed and complete the full course, even if you feel better. If symptoms persist or side effects occur, speak to your doctor or pharmacist.
