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Bactrim Side Effects
Nausea, vomiting, loss of appetite, and allergic skin reactions are the most common side effects reported with Bactrim. Some of the problems that are less common (but are potentially serious) include watery or bloody diarrhea, shortness of breath, and decreased urination. Although a skin rash is a very common side effect of Bactrim, it requires immediate medical attention.
As with any medicine, side effects are possible with Bactrim® (sulfamethoxazole/trimethoprim). However, not everyone who takes the medication will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or can easily be treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Bactrim. Your healthcare provider can discuss a more complete list of Bactrim side effects with you.)
Bactrim was approved long before the United States Food and Drug Administration required manufacturers to include detailed information about side effects. Therefore, only vague side effect information is available; the exact percentages of individual side effects are not provided.
Based on this limited information, the most common side effects of Bactrim include:
- Nausea
- Vomiting
- Loss of appetite
- Allergic skin reactions (such as a rash or itching).
Even though a skin rash due to Bactrim is quite common, it should always be reported to your healthcare provider. In general, it is recommended that you stop taking Bactrim at the first sign of a skin rash, as very dangerous reactions can develop (although this happens only rarely).
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD