Phenazopyridine (Pyridium) is a prescription or over-the-counter medication used to temporarily relieve pain, burning, and urgency caused by urinary tract infections (UTIs), irritation, or surgery. It works as a topical anesthetic for the bladder but does not treat the infection itself. Common side effects include headache, dizziness, stomach upset, and bright orange-to-red discoloration of urine, sweat, and tears.