Uses of Trimethoprim

Trimethoprim is used to treat bacterial infections of the urinary tract and the respiratory tract. It can also be used to prevent recurrent urinary tract infections. 

Therapeutic Category

Trimethoprim: Antibiotics

How Trimethoprim works

Trimethoprim is an antifolate antibacterial agent. It kills the susceptible bacteria by blocking the actions of an enzyme called dihydrofolate reductase which is essential for the formation of certain substances (folic acid) in the bacterial cell that gives them energy for growth and multiplication. As a result, it stops the bacteria from growing, and prevents the infection from spreading.

Common side effects of Trimethoprim

• high blood potassium levels (causing muscle cramps, irregular heart rhythm, headache, nausea, dizziness or diarrhea)
• headache
• skin rashes, hives
• thrush
• nausea, vomiting
• diarrhea

When to consult your doctor

Consult your doctor if you experience:

• serious allergic reactions (such as skin eruptions/lesions, deep swelling of the skin, swelling of the face, lips, tongue and throat and difficulty in breathing)
• chest pain
• shock or fainting
• severe blistering/peeling of the skin
• pancreatitis (signs may include a sudden, severe upper abdominal pain)
• jaundice (yellowing of the skin or whites of the eyes)

Health Tips for Trimethoprim

• Take Trimethoprim as advised by your physician. Strictly follow the dosing schedule as advised by your physician
•  Do not miss a dose or stop taking Trimethoprim without consulting your doctor as it may lead to growth of harmful bacteria within the body
• Perform routine health checkups and blood tests as recommended by your doctor to achieve fast recovery
• Before taking Trimethoprim, inform your doctor if you have any problems in your kidneys. You must also inform your doctor if you have folic acid deficiency, porphyria (inherited blood disorder) or uncontrollable diabetes as a precaution
• Trimethoprim may cause diarrhea in some individuals. Hydrate yourself by drinking plenty of fluids, such as water or fruit juices. Consuming ORS can also be beneficial. However, if you experience any bloody diarrhea with severe stomach pain contact your doctor immediately
• Trimethoprim is not suitable for use in women who are pregnant or breastfeeding and in children (aged below 6 years, including infants aged below 4 months)
• Trimethoprim may cause anemia or hyperkalemia (high blood potassium levels) in some individuals. To avoid this, your doctor will periodically monitor your RBC count and blood potassium levels as a precaution