Phenazopyridine hydrochloride is a urinary tract analgesic (azo dye) used for the symptomatic relief of pain, burning, urgency, frequency, and discomfort arising from irritation of the lower urinary tract mucosa. It is a local analgesic that exerts a direct topical effect on the urinary tract mucosa following renal excretion. It is NOT an antibiotic and does not treat the underlying infection. It is typically used as short-term adjunctive therapy during the initial 2-3 days of antibiotic treatment for urinary tract infections (UTIs) in India.
Adult: 200 mg orally three times a day, after meals.
Note: Administer after meals with a full glass of water to minimize gastric upset. Swallow tablet whole; do not crush or chew. Inform patient that urine (and possibly other body fluids) will turn orange-red. This is normal.
Phenazopyridine exerts a direct topical analgesic effect on the mucosa of the urinary tract (ureters and bladder). The exact mechanism is not fully elucidated but is believed to involve local anesthetic properties. It is excreted unchanged in high concentrations by the kidneys, where it comes into direct contact with and soothes the inflamed or irritated urothelium.
Pregnancy: Pregnancy Category B (US FDA). Animal studies have not shown risk, but no adequate, well-controlled studies in pregnant women. Use only if clearly needed and for the shortest duration. Should not be used as monotherapy for UTI in pregnancy; must be adjunct to appropriate antibiotics.
Driving: May cause dizziness or headache. Patients should be cautioned about operating machinery or driving until they know how the medication affects them.
| Sulfonamide Antibiotics (e.g., Cotrimoxazole) | Theoretical increased risk of methaemoglobinaemia. Clinical significance is uncertain but warrants caution. | Moderate |
| Nitrofurantoin | Increased risk of hemolytic anemia, especially in G6PD deficient patients. | Moderate |
| Antacids containing Magnesium Trisilicate | May reduce the absorption of phenazopyridine. Separate administration by at least 2 hours. | Minor |
| Probenecid | May decrease renal excretion of phenazopyridine, potentially increasing its plasma levels and risk of toxicity. | Moderate |
| Other Oxidizing Drugs | Increased risk of hemolytic anemia or methaemoglobinaemia. | Moderate |