What is Trimethoprim?
Trimethoprim is a wide spectrum of antibiotic medication for the treatment of cystitis in women and men. It is named after its active ingredient (also called trimethoprim) and is available in 200mg tablet form. One tablet is swallowed twice daily with water. The antibiotic works to prevent the growth of bacteria (usually E.coli or Escherichia coli type) in your body and cure the infection. A three-day course of Trimethoprim is the usual prescription for ordinary cystitis or a minor infection of the bladder or urinary tract. Trimethoprim can usually be prescribed to most patients, who meet the basic health requirements for the medication.
What is the active ingredient of Trimethoprim?
Trimethoprim tablets are named for their active ingredient, which is also called trimethoprim. It is an antibiotic used primarily for the treatment of bladder and urinary tract infections like cystitis. It may also be prescribed for inner ear infections and traveller’s diarrhoea. Trimethoprim attacks the bacteria that cause the infection.
How does Trimethoprim work?
Trimethoprim 200mg tablets are swallowed with a glass of water twice daily, usually for a total of three days. The active ingredient (also called trimethoprim) is an antibiotic that kills the bacteria that cause the initial infection and are continuing to multiply inside your urinary tract or bladder. It is important to take all the prescribed pills, even if you quickly begin to feel relief from the symptoms of cystitis. The infection may not be completely cured if you don’t complete the full course of Trimethoprim. Remaining hydrated by drinking water and avoiding caffeine (including soft drinks that contain caffeine), alcohol, and spicy food may ease symptoms and aid recovery.
Who can take Trimethoprim?
Our online GPs will usually consider prescribing Trimethoprim to both women and men who are suffering from cystitis. A quick online health check will ensure that the medication is safe for you to use. If you have medical issues that prevent you from receiving a Trimethoprim prescription, our GP may recommend that you consult a specialist.
If you are pregnant, you cannot take Trimethoprim. If you are breastfeeding, you should mention it on the online health questionnaire. Patients with kidney problems, or who are using certain prescription medications may also be unable to use Trimethoprim.
What doses of Trimethoprim are available?
Trimethoprim is available in 200mg tablets. These are taken twice daily for a total of three days. The cumulative dosage of 1,200 mg of Trimethoprim is usually enough to treat an ordinary infection of the bladder or urinary tract.
It is very important to take all the prescribed tablets and complete the course of antibiotics. Even though the symptoms of cystitis may rapidly ease, the bacteria that caused the infection could still be present inside your body. If you don’t take all the tablets, the bacteria may continue to multiply and the infection could return.
While you are taking the three-day course of Trimethoprim, you may be able to ease the symptoms of cystitis and aid recovery by drinking plenty of water. You should also avoid alcohol, caffeine (including caffeinated soft drinks) and spicy foods.
How do I take Trimethoprim?
Unless otherwise instructed by your online GP, take one 200mg Trimethoprim tablet in the morning and another at night. Continue to take the tablets in this way - and at the same time every day - without a break. It is important to take all the tablets that you have been prescribed. Swallow the tablets with a glass of water and be sure to drink enough water during the day.
Can I take Trimethoprim and drink alcohol?
Our online GPs generally do not recommend combining alcohol with any prescription medication, including antibiotics. In any case, it is strongly recommended that you completely abstain from drinking any alcohol if you are suffering from cystitis. Drinking alcohol can exacerbate your symptoms.
What are the side effects of Trimethoprim?
Your Trimethoprim tablets will come with a patient leaflet giving detailed information about the medication, its ingredients, possible side effects, and contraindications. Please read this leaflet carefully before you take any tablets. Keep the leaflet with the medication for future reference.
If you use Trimethoprim tablets exactly as directed by our online GP you are unlikely to experience any significant unwelcome side effects. A small minority of patients may experience some minor side effects.
Possible common side effects
- Itching and rash
- Stomach upset
- Loss of appetite
- Skin sensitivity to sunlight
- Swollen tongue
Very rarely patients may experience an adverse reaction to Trimethoprim. If you experience any of the following symptoms, you should discontinue your treatment and seek immediate medical advice.
- Allergic reaction symptoms of which may include hives (also known as nettle rash or urticaria), difficulty in breathing.
- Swelling of the face, lips, throat or tongue, or collapse.
- Aseptic meningitis which may show as a combination of symptoms such as headache, fever, stiff neck, tiredness.
- Feeling ill and your eyes become very sensitive to bright light.
- Severe skin reactions such as erythema multiforme (circular, irregular red patches), Stevens-Johnson syndrome (severe skin rash with flushing, fever, blisters or ulcers) or toxic epidermal necrolysis (severe rash involving reddening, peeling and swelling of the skin that resembles severe burns).
If you experience serious discomfort, we recommend that you go straight to your nearest casualty department. In an emergency dial 999.
When should I not take Trimethoprim?
Do not take Trimethoprim if you are allergic to the active ingredient (also called trimethoprim). You cannot take this medication if you are pregnant.
If you are taking any of the following medications or treatments, or if you are breast feeding, it is important that you mention them when you complete the online health questionnaire. You may still be able to take Trimethoprim, but your online GP will only issue a prescription if the medicine is safe for you to use.
- Antibiotics such as rifampicin
- Anticoagulants to prevent your blood clotting such as warfarin
- Ciclosporin (to prevent rejection after transplantation)
- Digoxin (to treat heart conditions)
- Phenytoin (to treat epilepsy)
- Pyrimethamine (to treat malaria)
- Bone marrow depressants
- If you have liver or kidney problems
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine. It is written for patients and gives information about taking or using a medicine. It is possible that the leaflet in your medicine pack may differ from the PDF-version from this website because it may have been updated since your medicine was packaged or the medicine is from another brand.