simple infections can be diagnosed and treated based on symptoms alone. oral antibiotics such as trimethoprim/sulfamethoxazole (tmp/smx), cephalosporins, nitrofurantoin, or a fluoroquinolone will shorten the time to recovery. all these drugs are equally effective. a three-day treatment with trimethoprim, tmp/smx, or a fluoroquinolone is usually enough. nitrofurantoin needs 5–7 days. with treatment, symptoms should improve within 36 hours. about 50% of people will get better without treatment within a few days or weeks. the infectious diseases society of america does not recommend fluoroquinolones as first treatment because of concerns that overuse will lead to resistance to this class of drugs, making these drugs less effective for more serious infections. despite this precaution, some resistance has developed to all of these drugs because to their widespread use. in some countries, trimethoprim alone is deemed to be equivalent to tmp/smx. children with simple utis are often helped by a three-day course of antibiotics.