Nitrofurantoin is an antibiotic medication used to treat urinary tract infections (UTIs) caused by certain types of bacteria. It works by stopping the growth of bacteria in the urinary tract, thereby treating the infection. Nitrofurantoin is commonly prescribed for uncomplicated UTIs, such as cystitis (bladder infection). It is usually taken orally in the form of capsules or tablets. It’s important to take the full course of treatment as prescribed by a healthcare provider, even if symptoms improve before the medication is finished, to ensure the infection is fully eradicated and to prevent antibiotic resistance. Common side effects of nitrofurantoin may include nausea, vomiting, diarrhea, and headache. If you experience severe or persistent side effects, contact your doctor.