Phenazopyridine
Mechanism :
Phenazopyridine is a urinary tract analgesic. Exactly how phenazopyridine works is not known. It is thought to work by relieving pain on the lining of the urinary tract.
Indication :
- Relieving pain, burning, urgency, frequent urination, and discomfort caused by irritation of the lower urinary tract.
Contraindications :
Allergic to any ingredient in phenazopyridine.
Decreased kidney function.
Dosing :
<6 years:
Safety and efficacy not established
Dysuria in 6 to 18 years:
12 mg/kg/day orally divided into 3 doses for two days. Maximum dose: 600 mg/day.
Adverse Effect :
Dizziness, headache, vertigo, indigestion, itching of the skin, stomach cramps or pain, blue or blue-purple color of skin, fever, confusion, shortness of breath, tightness in chest, wheezing, troubled breathing, skin rash, sudden decrease in the amount of urine, swelling of face, fingers, feet, and/or lower legs, unusual tiredness or weakness, weight gain, yellow eyes or skin
Interaction :
Renal Dysfunction: Severe Potential Hazard, High plausibility. The use of phenazopyridine is contraindicated in patients with impaired renal function. Phenazopyridine is primarily eliminated unchanged by the kidney and may accumulate to toxic levels during prolonged administration in such patients. Reported cases of toxicity due to overdosage have resulted in acute renal failure and methemoglobinemia.
G-6-Pd Deficiency: Severe Potential Hazard, Moderate plausibility. Patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency may be at increased risk for phenazopyridine-induced methemoglobinemia and hemolytic anemia. These conditions have occurred rarely in other patients, except due to acute phenazopyridine overdose or impaired renal function. Therapy with phenazopyridine should be administered cautiously in patients with G-6-PD deficiency.
Hepatic Dose :
Reduction of dose is advisable as metabolism is hepatic and the metabolites are potentially active or toxic.