Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Jul 19, 2022

Side Effects


Bactrim Side Effects

Common side effects of Bactrim are listed below. Tell your doctor if these side effects are severe or if they do not go away over time.

  • Nausea, vomiting, loss of appetite
  • Rash, hives
  • Sensitivity to the sun


Bactrim can also cause some very serious side effects. You should call your doctor immediately or seek emergency medical help if you have the following signs and symptoms:

  • Allergic reaction
  • Severe skin reaction
  • Severe diarrhea


The above list may not include all the potential adverse reactions of Bactrim. Call your doctor or seek medical treatment if you have a serious drug reaction. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Bactrim overdose: In case of a known or suspected overdose, call your doctor immediately and seek medical treatment. You can also call your provincial poison control center or the national poison control center at 1-800-222-1222. If a person has collapsed, had a seizure, has trouble breathing, or cannot be awakened, call 911 immediately. Overdose symptoms may include loss of appetite, severe stomach pain, nausea, vomiting, headache, dizziness, drowsiness, confusion, and unconsciousness.

Source: FDA