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Trimpex Side Effects

Generic Name: trimethoprim

Note: This document contains side effect information about trimethoprim. Some of the dosage forms listed on this page may not apply to the brand name Trimpex.

For the Consumer

Applies to trimethoprim: oral solution, oral tablet

Along with its needed effects, trimethoprim (the active ingredient contained in Trimpex) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking trimethoprim:

Less common Rare
  • Black, tarry stools
  • blood in urine or stools
  • bluish fingernails, lips, or skin
  • changes in facial skin color
  • chills
  • difficult breathing or shortness of breath
  • fever with or without chills
  • general feeling of discomfort or illness
  • headache
  • joint or muscle pain
  • nausea
  • neck stiffness
  • pale skin
  • pinpoint red spots on skin
  • redness, blistering, burning, tenderness, peeling, or loosening of skin or mucous membranes
  • redness, swelling, or soreness of tongue
  • red skin lesions, often with a purple center
  • sore throat
  • swelling
  • thickened or scaly skin
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Some side effects of trimethoprim may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

For Healthcare Professionals

Applies to trimethoprim: compounding powder, oral solution, oral tablet


Common (1% to 10%): Rash (e.g., maculopapular, morbilliform, pruritic), pruritus
Rare (less than 0.1%): Photosensitivity, angioedema, erythema multiforme, Stevens Johnson syndrome, toxic epidermal necrolysis (Lyell Syndrome
Frequency not reported: Exfoliative dermatitis, urticaria[Ref]


Common (1% to 10%): Epigastric distress, nausea, vomiting, glossitis, abdominal pain, sore mouth
Frequency not reported: Pseudomembranous colitis, Clostridium difficile associated diarrhea[Ref]


Frequency not reported: Thrombocytopenia, leukopenia, neutropenia, megaloblastic anemia, methemoglobinemia[Ref]


Rare (less than 0.1%): Cholestatic jaundice
Frequency not reported: ALT and AST elevations, elevated bilirubin[Ref]


Rare (less than 0.1%): Anaphylaxis[Ref]


Frequency not reported: Hyperkalemia, hyponatremia[Ref]


Frequency not reported: Myalgia[Ref]

Nervous system

Rare (less than 0.1%): Aseptic meningitis, headache[Ref]


Frequency not reported: Fever[Ref]


Frequency not reported: Increased BUN, increased serum creatinine[Ref]


1. "Product Information. Trimethoprim (trimethoprim)." Teva Pharmaceuticals USA, North Wales, PA.

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Some side effects of Trimpex may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.