Phenazopyridine information from DrugsUpdate
L - Caution when used during lactation
LI - Lab *
Phenazopyridine is a chemical which, when secreted into the urine, has a local analgesic effect. It is often used to alleviate the pain, irritation, discomfort, or urgency caused by urinary tract infections, surgery, or injury to the urinary tract. However, phenazopyridine is not an antibiotic; it does not cure infections.
Phenazopyridine is an azo dye that exerts an analgesic effect in the urinary tract.
Absorbed from the GI tract (oral).
Via urine (65% as unchanged drug; 18% as paracetamol).
GI disturbances, headache; rash; hepatotoxicity; haemolytic anaemia, methaemoglobinaemia; discolouration of urine and other body fluids; staining of contact lens; crystal deposits in urinary tract.
Potentially Fatal: Acute renal failure.
Avoid prolonged use. Pregnancy and lactation. G6PD deficiency. Stop treatment if skin or sclerae discolouration occur. Elderly.
Pain and irritability in cystitis, prostatitis and urethritis
Adult: As hydrochloride: 200 mg tid. When combined with an antibiotic, max duration of treatment is 2 days, although lower doses for at least a week have been given.
Child: As hydrochloride: 12 mg/kg/day in 3 divided doses for 2 days.
CrCl (ml/min) Dosage Recommendation
50-80 Give dose every 8-16 hours.
Should be taken with food. (Take after meals.)
List of Contraindications
Caution when used during pregnancy
Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).
Caution when used during lactation
Impaired renal function or severe hepatitis. CrCl <50 ml/min.
May interfere with urine ketone and protein tests. May delay reactions with glucose oxidase reagents. May occasionally cause false-positive tests with Tes-Tape.