List of side effects of trimethoprim/sulfamethoxazole

Trimethoprim/sulfamethoxazole (TMP/SMX), also known as co-trimoxazole, is a combination antibiotic used to treat a variety of bacterial infections. This medication combines two antibiotics: trimethoprim and sulfamethoxazole, which work together to inhibit the production of folic acid in bacteria, thereby stopping bacterial growth. While TMP/SMX is effective in treating infections, it can also cause a range of side effects in some patients. The following is a list of known side effects associated with trimethoprim/sulfamethoxazole, categorized by their frequency and severity.

Common Side Effects

Common side effects of TMP/SMX include:

• Nausea and vomiting
• Rash
• Itching
• Dizziness
• Fatigue

Less Common Side Effects

Less common side effects may include:

• Diarrhea
• Headache
• Muscle aches
• Fever
• Sensitivity to sunlight (photosensitivity)

Serious Side Effects

While rare, some serious side effects can occur, including:

• Stevens-Johnson syndrome (a severe skin reaction)
• Toxic epidermal necrolysis (a more severe form of Stevens-Johnson syndrome)
• Agranulocytosis (a severe decrease in white blood cells)
• Thrombocytopenia (low blood platelet count)
• Hepatitis (inflammation of the liver)
• Hyperkalemia (high potassium levels in the blood)
• Anaphylaxis (a severe allergic reaction)

Long-term Side Effects

Long-term use of TMP/SMX may lead to:

• Folate deficiency (due to inhibition of folic acid synthesis)
• Kidney stones (rare)

Precautions

Patients with a known allergy to trimethoprim, sulfamethoxazole, or any other sulfa drugs should not take TMP/SMX. It is also advised to use caution in patients with kidney or liver disease, folate deficiency, or those with a history of blood disorders.

Interactions

TMP/SMX can interact with other medications, potentially leading to increased risk of side effects or decreased effectiveness of either the TMP/SMX or the other medication. Patients should inform their healthcare provider of all medications they are taking, including over-the-counter drugs and supplements.

Conclusion

While trimethoprim/sulfamethoxazole is an effective treatment for various bacterial infections, it is important for patients to be aware of the potential side effects. Anyone experiencing severe or persistent side effects should seek medical attention immediately. This list is incomplete; you can help WikiMD by expanding it.