Bactrim and Septra
(sulfamethoxazole and trimethoprim)

Bactrim, Bactrim DS, Septra, Septra DS and Cotrim all contain two components: sulfamethoxazole and trimethoprim. The following is the information about both of these components.

Sulfamethoxazole:
This drug is an antibiotic used to treat a wide variety of bacterial and protozoal infections, particularly of the urinary tract.

Potassium
In combination with trimethoprim, sulfamethoxazole has increased blood levels of potassium, accompanied by increases in other constituents of blood (creatinine and BUN). In particular, people with impaired kidney function should be monitored and treated by their doctors if such abnormalities are detected.1 It would appear wise for people taking this drug to talk with the prescribing physician before taking any potassium supplements or potassium-containing products such as Morton Salt Substitute, No Salt, and Lite Salt.


Trimethoprim:
Trimethoprim is an antibiotic used to treat urinary tract and other infections.

Folic acid
Folic acid deficiency increases risks of toxicity from this drug. It has been reported that trimethoprim may also partially deplete folic acid levels.2 Folic acid deficiency can be determined by blood tests.

Potassium
In combination with sulfamethoxazole or by itself, trimethoprim has increased blood levels of potassium, accompanied by increases in other constituents of blood (creatinine and BUN). In particular, people with impaired kidney function should be monitored and treated by their doctors if such abnormalities result from taking this drug.3 It makes sense for people taking trimethoprim to talk with the prescribing physician before taking any potassium supplements or potassium-chloride-containing products (such as Lite Salt, No Salt, Morton Salt Substitute, etc.).

References:

1. Alappan R, Perazella MA, Buller GK. Hyperkalemia in hospitalized patients treated with trimethoprim-sulfamethoxazole. Ann Intern Med 1996;124:316-20.
2. Kahn SB, Fein SA, Brodsky I. Effects of trimethoprim on folate metabolism in man. Clin Pharmacol Ther 1968;9:550-60.
3. Alappan R, Perazella MA, Buller GK. Hyperkalemia in hospitalized patients treated with trimethoprim-sulfamethoxazole. Ann Intern Med 1996;124:316-20.


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The information presented in HealthNotes Online is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your physician, nutritionally-oriented health care practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.