Trimethoprim (Systemic)

Brand Names : Proloprim, Trimpex

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For trimethoprim, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to trimethoprim. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy - Studies have not been done in humans. Studies in rats have shown that trimethoprim causes birth defects. Studies in rabbits have shown that trimethoprim causes a decrease in the number of successful pregnancies. However, in the few reports where trimethoprim was taken by pregnant women, trimethoprim has not been reported to cause birth defects or other problems in humans.

Breast-feeding - Trimethoprim passes into the breast milk. However, this medicine has not been reported to cause serious problems in nursing babies.

Children - This medicine has been used in a limited number of children 2 months of age or older, and tested in children 12 years of age or older. In effective doses, the medicine has not been shown to cause different side effects or problems in children than it does in adults.

Older adults - Elderly people may be more sensitive to the effects of trimethoprim. Blood problems may be more likely to occur in elderly patients who are taking diuretics (water pills) along with this medicine.

Other medicines - Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking trimethoprim, it is especially important that your health care professional know if you are taking any of the following:

• Anticonvulsants (seizure medicine) or
• Methotrexate (e.g., Mexate) or
• Pyrimethamine (e.g., Daraprim) or
• Triamterene (e.g., Dyrenium) - Use of these medicines with trimethoprim may increase the chance of side effects affecting the blood

Other medical problems - The presence of other medical problems may affect the use of trimethoprim. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia - Patients with anemia may have an increased chance of side effects affecting the blood

• Kidney disease - Patients with kidney disease may have an increased chance of side effects

• Liver disease - Patients with liver disease may have an increased chance of side effects