I came to work in the urology department of the hospital in 1996, and over the past 20 years or so, many inexpensive and effective drugs have faded out of sight, leaving us with a great deal of fondness for those days. Now, the pharmacist in the window to issue drugs, often encounter patients to buy some old drugs, encounter young pharmacists, often do not know that there are such drugs. I remember once, a patient with a lower urinary tract infection, with a doctor’s prescription for furantoin, ran through many hospitals and pharmacies but could not buy it. When he finally found out that our hospital had it, he came all the way over here and made sure the doctor prescribed more. The excitement was overwhelming and he kept thanking us. Furantoin, also known as furatantin, may be related to interfering with bacterial enzymes and causing disruptions in bacterial metabolism. The antibacterial mechanism of action is different from that of drugs such as cephalosporins and quinolones, so there is no cross-resistance. This drug has very good antibacterial effect on urinary tract infections and can treat most urinary tract infections caused by sensitive bacteria. However, due to its cheap price, many suppliers do not supply the drug to hospitals, and many hospitals no longer see this drug. Furantoin has a very good antibacterial effect on common pathogens in urinary tract infections such as Escherichia coli (E. coli), Enterobacter cloacae, Klebsiella pneumoniae, Enterococcus faecalis, Enterococcus faecalis, and even on Gram-negative bacteria that produce ultra-broad-spectrum enzymes such as Escherichia coli, Klebsiella pneumoniae, and vancomycin-resistant enterococci, so it is widely used in the United States and Europe for the treatment of urinary tract infections . Drugs such as furantoin have high concentrations in urine, but their blood concentrations are low, so they are only used for the treatment of lower urinary tract infections, but not for upper urinary tract infections. The antimicrobial activity is not affected by pus and tissue breakdown products, and is more active in acidic urine. 100 mg three times daily can treat most urinary tract infections caused by sensitive bacteria. It has also been used as an antibacterial treatment for long-term urinary tract infections, and is administered as 50 mg or 100 mg daily before bedtime for 3-6 months. Long-term use of this product for more than 6 months may lead to diffuse interstitial pneumonia or pulmonary fibrosis, which should be monitored closely for early detection and timely discontinuation. Therefore, those who use this product for long-term prophylaxis should weigh the pros and cons. 2. Because furantoin can cross the placental barrier and the fetal enzyme system is not yet fully developed, it should not be applied to pregnant women in the second trimester of pregnancy, and it is prohibited for full-term pregnant women to avoid the possibility of fetal hemolytic anemia. A small amount of furantoin can enter the breast milk, and the advantages and disadvantages must be considered when applied to lactating women. 4.The following conditions should be used with caution: (1) glucose-6-phosphate dehydrogenase (G6PD) deficiency; (2) peripheral neuropathy; (3) pulmonary disease; (4) renal hypofunction. 5.Furantoin should be taken with food to reduce gastrointestinal irritation; absorption is delayed, but total absorption is increased, and the retention time of therapeutic concentration in urine is prolonged. 6. The course of treatment should be at least 7 days, or continue to use the drug until the bacteria in the urine are cleared for more than 3 days.