Pyridium (Phenazopyridine) Prescription for UTI with Normal Renal Function
For a patient with uncomplicated UTI and normal renal function, prescribe phenazopyridine 200 mg orally three times daily after meals for a maximum of 2 days, used concurrently with appropriate antibiotic therapy. 1
Standard Dosing Regimen
- 200 mg tablets: One tablet orally three times daily after meals 1
- 100 mg tablets: Two tablets orally three times daily after meals 1
- Maximum duration: 2 days when used with antibacterial therapy 1
The FDA label explicitly states that treatment duration should not exceed 2 days because there is no evidence that combined administration of phenazopyridine with antibiotics provides greater benefit than antibiotics alone after this period 1.
Critical Clinical Context
Phenazopyridine provides only symptomatic relief and has no antibacterial properties 1, 2. It is indicated solely for symptomatic relief of pain, burning, urgency, frequency, and discomfort arising from lower urinary tract irritation 1. The drug must always be prescribed alongside definitive antibiotic therapy, never as monotherapy 1.
A case report demonstrated the danger of using phenazopyridine alone: a 40-year-old woman with uncomplicated cystitis used over-the-counter phenazopyridine without antibiotics, which allowed progression to acute pyelonephritis requiring IV antibiotics 2. This underscores that symptomatic improvement does not indicate infection resolution.
Safety Considerations and Contraindications
Absolute contraindication in renal impairment: Phenazopyridine is contraindicated in patients with any degree of renal insufficiency 1, 3. A case report documented acute renal failure in a 17-year-old after ingesting only 1,200 mg (six 200-mg tablets), despite having no prior kidney disease 3.
Pediatric dosing requires extreme caution: A 2-year-old developed methemoglobinemia (29.1%) requiring methylene blue therapy after ingesting only three 200-mg tablets (approximately 50 mg/kg) 4. Children who ingest even small amounts should be observed for 4-6 hours or have methemoglobin levels checked 4.
Common Pitfalls to Avoid
- Never prescribe beyond 2 days: Extended use provides no additional benefit and increases toxicity risk 1
- Never use as monotherapy: Always combine with appropriate antibiotics from day one 1, 2
- Screen for renal function: Even mild renal impairment is a contraindication 1, 3
- Warn patients about urine discoloration: Phenazopyridine causes orange-red discoloration of urine, which is expected and harmless 1
Clinical Efficacy Data
A randomized, placebo-controlled trial in 60 women with acute uncomplicated cystitis demonstrated that a single 200-mg dose of phenazopyridine provided significant symptom relief within 6 hours 5. General discomfort decreased by 53.4% versus 28.8% with placebo, pain during urination decreased by 57.4% versus 35.9%, and urinary frequency decreased by 39.6% versus 27.6% 5. The drug was well-tolerated with no serious adverse events 5.
Prescription Template
Phenazopyridine 200 mg
- Take one tablet by mouth three times daily after meals
- Duration: 2 days only
- Dispense: 6 tablets (no refills)
- Must be taken with prescribed antibiotic therapy
- Urine will turn orange-red (this is normal)
- Stop immediately if skin or eyes turn yellow