Cystitis (UTI)

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  • Trimethoprim


Cystitis (UTI)
  • Medication features

    Urinary tract infections (UTI) are a common medical issue and can cause uncomfort, particularly when urinating. They are caused when bacteria enters the urinary tract and causes an infection. Trimethoprim is an antibiotic that treats urinary tract infections. This medication is usually taken as a short course lasting three days but can be taken for longer if required depending on the severity of the infection. It is taken twice a day, one in the morning and evening. It is recommended that the course should be completed even if symptoms have subsided, to prevent a re-occurrence. It’s also important to drink plenty of water whilst treating a UTI. 

    • Trimethoprin is an antibiotic to treat UTIs
    • Simple tablet with a twice daily dose


NOTE: After selecting this product, you will need to complete a short assessment, so we can make sure this medication is suitable for you. Pricing is provided as a reference only. The final decision on issuing this medication remains with our Prescriber / Pharmacist.

Trimethoprim is an antibiotic typically used to treat urinary tract infections, such as cystitis. It should help to relieve any symptoms within a few days. This medication is available to order from Pharmacy Online.


  • How long will it take to work?

    Of course, everyone is different and the effectiveness of the medication will vary. But your UTI symptoms should start to improve within a day of taking the medication. Even if you no longer have symptoms, you need to ensure that you complete the entire course of antibotiics to prevent the infection from reoccurring. If you still have symptoms or your condition has gotten worse after completing the course of Trimethoprim you should contact your doctor.

  • Is it safe to use Trimethoprim continuously?

    You should not continue to take Trimethorprim without speaking to your doctor. This medication is an antibiotic and continual use can affect how well other medications work for you in the future. If you have continual UTIs, you should contact your doctor.

  • How can I manage side effects?

    Side effects are common whilst taking any form of medication. Certain side effects can occurr when taking this form of UTI treatment such as diarrhoea. This can be reduced by taking over the counter treatments. Nausea can be prevented by taking the medication with food, or just after you’ve eaten. Vomiting is also a common side effect, however this can be treated with cyclizine, promethazine, and prochlorperazine, which can be purchased here at Pharmacy Online.

  • Can I drink alcohol while taking this medication?

    Trimethoprim is not directly affected by alcohol; you can drink alcohol whilst on this medication.

    It is important to remember that alcohol acts as a diuretic and may cause the Trimethoprim to be flushed out of the system quicker; this may result in the course being less effective. It is therefore recommended to drink in moderation. It’s important to continuously drink plenty of water whilst treating a UTI.

  • What should I do if I miss a dose?

    It’s important to remember to take your prescribed medication at the outlined times throughout the course of antibiotics. However, if you forget to take a tablet within 24 hours since your last one, then you need to take the next tablet as soon as possible. 

    However, if you have forgotten to take it after 24 hours since your last tablet, then you should resume taking the medication as normal by taking the next tablet. You shouldn’t over compensate tablets if you have forgotten one as this can be harmful to your health and recovery.

    You must remember to take Trimethoprim regularly as directed and to ensure you complete the course as failing to do so could prolong the infection.

  • Should I take Trimethoprim with food?

    Trimethoprim can be taken with or without food. It is however recommended to take Trimethoprim with plenty of water.

Side Effects

When taking any medication, side effects are common and usually very mild and not noticeable. However, there can be some side effects that can be disruptive and uncomfortable. Some side effects can also be serious and should be reported to your doctor straight away. If you are concerned about side effects before starting treatment, speak to our team at Pharmacy Online who will be happy to answer all your questions.

Side effects may include:

  • Nausea and vommiting 
  • Itching or mild rash on skin
  • Headaches or migraines 
  • Diarrhoea and stomach cramps

As mentioned before, there can be some serious side effects that occurr when taking this form of medication. Although very rare, some side effects can be serious and cause health complications. It’s important to be aware of what these more serious side effects could be when taking this medication. If you experience any of the below side effects, you should stop taking the medication immediately and contact your GP straight away:

  • Chest pain
  • Diarrhoea containing blood
  • Muscle weakness
  • Unexplained bruising or bleeding
  • Swelling of the tongue, difficulty breathing, talking or tightness of the chest could be an indication of a severe allergic reaction to this medication.


Info Leaflet

Before taking any medicines, regardless of whether they are over the counter or prescription-only, it is essential always to read the patient information leaflet.

Patient Information Leaflet