What Is Sulfamethoxazole/Trimethoprim Used For?
Sulfamethoxazole/trimethoprim is used for treating various types of bacterial infections, including urinary tract infections, acute worsening of chronic bronchitis, and ear infections. It is also approved to prevent Pneumocystis carinii pneumonia in people with weakened immune systems. Healthcare providers may occasionally recommend off-label sulfamethoxazole/trimethoprim uses as well, such as for preventing (instead of treating) different infections and for treating acne.
Sulfamethoxazole/trimethoprim (Bactrim®, Bactrim® DS, Septra®, Septra® DS, Sulfatrim®) is a combination antibiotic used to treat several different infections. In particular, it is approved for the treatment of the following infections:
- Ear infections
- Shigellosis (a form of dysentery)
- Traveler's diarrhea
- Urinary tract infections (UTIs), such as bladder infections
- Acute worsening of chronic bronchitis
- A certain types of pneumonia known as Pneumocystis carinii pneumonia.
Sulfamethoxazole/trimethoprim is also approved to prevent Pneumocystis carinii pneumonia in people with weakened immune systems at risk for the infection (such as people with HIV or AIDS).
Sulfamethoxazole/trimethoprim is approved for treating the above infections only when they are caused by certain types of bacteria. Not all bacteria will respond to this drug. Even among the types of bacteria that do respond to sulfamethoxazole/trimethoprim, some strains may have become resistant and may have different resistance patterns in different regions in the country. This means that some bacteria may be susceptible to sulfamethoxazole/trimethoprim in certain parts of the country but not in others.
Like all antibiotics, sulfamethoxazole/trimethoprim is completely ineffective for treating viral illnesses (such as the common cold or the flu).