The yellow urine after taking nifurtimox capsules is due to the staining of the drug. When nifurtimox is used to treat urinary tract infections, a large amount of the prototype form of the drug is present in the urine, so that the concentration in the urine is high and can be used to treat urinary tract infections. However, it can also cause yellowish staining of the urine, which can return to normal color after stopping the intake of the related drug. It is necessary to maintain a certain amount of water intake during the medication period, ensuring that the water intake is around 1500-2000ml per day. At the same time, according to the results of the routine urine examination, if necessary, oral sodium bicarbonate tablets to alkalize the urine and enhance the antibacterial ability. In addition to furan antibiotics that can easily cause yellow urine, sulfonamide antibiotics can also cause yellow urine after oral administration, and vitamin B family can also appear yellow urine after oral administration. These are related to the relatively high concentration of drugs in the urine, or their metabolites in the urine concentration, so it will cause the yellow color of urine.