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Is Trimethoprim an Effective Treatment for Cystitis?

Reviewed by
Date published
15/12/2020
Date last updated
04/12/2020
Length of read
3 Minutes

Trimethoprim is one of the most commonly used drugs for treating urinary tract infections and cystitis. As an antibiotic, trimethoprim works by killing the bacteria associated with the aforementioned illnesses. Within this guide, we will uncover just how effective trimethoprim is for treating cystitis.

Is trimethoprim effective?

The short answer is: yes! Trimethoprim is a fast-acting medication that works within just a few hours of taking it. By stopping the growth of bacteria that causes cystitis, trimethoprim enables your body’s immune system to fight off the infection more effectively.

Several clinical studies show that trimethoprim is highly effective in treating UTIs --- easing most of the cystitis symptoms you feel within 24 hours. Since this medicine is well-tolerated, you experience fewer side effects, too.

How does trimethoprim work?

Cystitis is usually caused by the imbalance of natural bacteria found in your urinary tract. Untreated, this infection can spread toward the bladder, causing further damage. That’s why it’s important to treat UTIs as soon as possible.

Simply put, trimethoprim works by inhibiting the growth and spread of bacteria. This gives your immune system enough time to get rid of the existing infection for good.

Who can take trimethoprim?

Adults and children can take trimethoprim safely. However, this medicine is not suitable for people who have:

  • Kidney problems
  • Liver issues
  • Anaemia
  • Low amount of folic acid in the blood
  • Had allergic reactions to trimethoprim in the past

Women who are pregnant or are already pregnant are also cautioned against using trimethoprim. Remember that Trimethoprim works by lowering the levels of folate in the body. Folate or folic acid is important for the baby’s normal development. If you must take trimethoprim, your doctor may prescribe you with high doses of folic acid as a supplement especially during the first 12 weeks of pregnancy.

How should I take trimethoprim?

You take two doses of trimethoprim a day --- one in the morning and one in the evening. Since trimethoprim doesn’t cause an upset stomach, you can take this medicine with or without food. Your daily dose of trimethoprim will depend on the illness you have. For example, for treating UTI, your doctor may recommend taking trimethoprim 200mg twice a day.

Never take two doses of trimethoprim at the same time. If you forget a dose, take it as soon as you remember. However, if it's almost time for your next dose, just skip the missed dose and continue as usual.

What are the side effects of trimethoprim?

Trimethoprim is a very well-tolerated drug. This means that most people don’t experience side effects associated with this medication. However, like all medicines, trimethoprim also has some side effects. Below are the most common ones which happen in 1% of patients:

  • Itching
  • Mild rash
  • Feeling sick
  • Diarrhoea
  • Headaches

Serious side effects of trimethoprim are rare (happens only to 1 in 1000 patients). These include:

  • Abnormal heartbeat
  • Chest pains
  • Muscle weakness
  • Serious skin reactions (blisters, skin ulcers, swelling etc.)
  • Over-sensitivity to bright light coupled with fever, headache, tired, feeling ill, and stiff neck
  • Unexplained bruising or bleeding

If you encounter any of these symptoms, consult with your doctor right away.