Infections caused by susceptible bacteria that are resistant to other antibiotics, including methicillin-resistant Staphylococcus aureus (MRSA)

Chronic infection of the prostate (prostatitis)

Bladder infections in women

Prevention of recurring urinary tract infections (UTIs) in women and children

Intestinal infections due to various bacteria, such as Escherichia coli (E. coli)

Treatment and prevention of pneumonia due to Pneumocystis jirovecii (a fungus)

Chronic prostatitis and prevention and treatment of urinary tract infections in people who are allergic to sulfonamides

Nausea, vomiting, and diarrhea

Allergic reactions (including rashes)

Crystals in urine (rare)

A decrease in white blood cell and platelet counts

Sensitivity to sunlight

Kidney failure in people who have kidneys that are not functioning well