What is Trimethoprim 200mg?
Trimethoprim is an antibiotic used to treat bacterial infections, specifically bladder infections (cystitis) and urinary tract infections (UTIs). It is listed on the World Health Organization’s List of Essential Medicines. As a prescription medication, it is not available over the counter.
Trimethoprim is highly effective for treating cystitis. However, in some regions of the UK, there is increasing resistance to this antibiotic. As a result, you may have previously been treated with another medication called nitrofurantoin. If nitrofurantoin was unsuitable for you or caused side effects, trimethoprim is a suitable alternative for treating your UTI.
How does Trimethoprim 200mg work?
Trimethoprim 200mg is an antibiotic that works by inhibiting bacterial growth, thus treating bacterial infections. Here’s how it works:
Mechanism of Action:
- Inhibition of Folic Acid Synthesis:
- Folic Acid Role: Bacteria need folic acid to produce DNA, RNA, and proteins, which are essential for their growth and replication.
- Dihydrofolate Reductase Inhibition: Trimethoprim specifically targets and inhibits an enzyme called dihydrofolate reductase. This enzyme is crucial for the conversion of dihydrofolic acid to tetrahydrofolic acid, a form of folic acid that bacteria need to synthesize their genetic material.
- Bacterial Death: By blocking this enzyme, trimethoprim prevents bacteria from producing the necessary components for their replication and survival, ultimately leading to bacterial cell death.
Effectiveness:
- Bacteriostatic: At lower concentrations, trimethoprim is bacteriostatic, meaning it stops bacteria from multiplying.
- Bactericidal: At higher concentrations, trimethoprim can be bactericidal, meaning it can kill the bacteria outright.
Use in Treating Cystitis and UTIs:
- Target Bacteria: Trimethoprim is particularly effective against a variety of Gram-negative and Gram-positive bacteria that commonly cause urinary tract infections, including Escherichia coli (E. coli).
- Symptom Relief: By reducing bacterial load in the urinary tract, trimethoprim alleviates symptoms associated with UTIs, such as pain, burning during urination, and frequent urination.
How do you take Trimethoprim 200mg?
The NHS recommends that for most uncomplicated cases of cystitis, Trimethoprim 200mg tablets should be taken twice daily, one dose every 12 hours, until the prescribed course is completed. Typically, this is a three-day course for uncomplicated cystitis, but it can also be prescribed as a seven-day course.
Dosage Instructions:
- Take one 200mg tablet twice a day, every 12 hours.
- Complete the entire prescribed course, even if symptoms improve.
- Begin taking Trimethoprim as soon as you notice the onset of cystitis symptoms.
Other antibiotics your doctor may consider more suitable for you include nitrofurantoin, quinolones, or amoxicillin. Speak to your healthcare provider to learn more about treating UTIs with antibiotics.
Does Trimethoprim 200mg interact with any medicines?
Trimethoprim 200mg tablets should not cause harmful interactions with most other medications. However, avoid taking Trimethoprim if you currently take any of the following:
- ACE inhibitors (such as ramipril)
- Azathioprine
- Cyclosporin
- Dapsone
- Digoxin
- Eplerenone
- Heparin
- Mercaptopurine
- Methotrexate
- Phenytoin
- Procainamide
- Pyrimethamine
- Repaglinide
- Rifampicin
- Warfarin
