Side Effects of Sulfamethoxazole/Trimethoprim
Common Side Effects of Sulfamethoxazole/Trimethoprim
Sulfamethoxazole/trimethoprim was approved long before the United States Food and Drug Administration required manufacturers to include highly detailed information about side effects in the prescribing information for medications. Therefore, only vague sulfamethoxazole/trimethoprim side effect information is available; the exact percentages of individual side effects are not provided in the sulfamethoxazole/trimethoprim prescribing information.
Based on this limited information, the most common sulfamethoxazole/trimethoprim side effects include:
- Loss of appetite
- Nausea, with or without vomiting
- Allergic skin reactions (such as a rash or itching).
Even though a skin rash due to sulfamethoxazole/trimethoprim is quite common, it should always be reported to your healthcare provider. In general, it is recommended that you stop taking sulfamethoxazole/trimethoprim at the first sign of a skin rash, as very dangerous reactions can develop (although this happens only rarely).
Other reported sulfamethoxazole/trimethoprim side effects include:
- A spinning sensation (vertigo)
- Ringing of the ear (tinnitus)
It is possible that you may experience some or none of the side effects listed in this article. Unfortunately, there is no way for your healthcare provider to know beforehand if you will have side effects from a medicine that you have never tried. Therefore, make sure to let your healthcare provider know if you develop any side effects while taking sulfamethoxazole/trimethoprim or if something "just does not seem right." While it may not be a side effect, your healthcare provider will be able to diagnose and treat the problem.