Metronidazole is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis and amebiasis.

Trimethoprim is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for Pneumocystis pneumonia in people with HIV/AIDS.

Azithromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes middle ear infections, strep throat, pneumonia, traveler's diarrhea and certain other intestinal infections.

Clarithromycin is an antibiotic used to treat various bacterial infections. This includes strep throat, pneumonia, skin infections, H. pylori infection and Lyme disease.