Urinary tract antibacterials
Urinary tract antibacterials become concentrated in the urine and kill bacteria in the bladder while reaching only low levels elsewhere in the body. Nitrofurantoin and fosfomycin treat uncomplicated bladder infections and are not used for kidney or bloodstream infections. Nausea and headache are common, and nitrofurantoin can turn urine brown. Nitrofurantoin can rarely cause serious lung reactions, liver injury, and nerve damage, especially with long-term use, and it is avoided when kidney function is poor.