Flavoxate hydrochloride tablets are mainly used to relieve smooth muscle spasm, which can effectively and quickly treat the symptoms of frequent and urgent urination caused by urinary tract infection or prostatitis, and also to relieve ureteral spasm, thus treating renal colic caused by ureteral stones and kidney stones. The main side effect of the current drug is that it may induce urinary retention or constipation. If you have difficulty urinating or defecating during the drug, you should immediately discontinue taking the drug and use some other drugs to counteract the adverse reaction. Flavoxate hydrochloride tablets may also cause dizziness, headache, and arrhythmia during the course of administration, and should be discontinued as soon as they occur.