What is Bactrim used for?

Drugs.com says that Bactrim is used to treat bacterial infections, including traveler's diarrhea, urinary tract infections, ear infections, bronchitis and the pneumocystis variant of pneumonia. WebMD says that Bactrim is a combination of sulfamethoxazole and trimethoprim and is ineffective at treating non-bacterial ailments, such as viral or fungal infections.

According to Wikipedia, Bactrim is part of the World Health Organization's List of Essential Medicines because of its ability to fight a broad range bacterial infections. Despite its high efficacy, Bactrim also has a higher rate of allergic reaction than either sulfamethoxazole or trimethoprim alone, which has led some countries to restrict its use.