Editing Functional: Pharmacological Management of LUTS (section)

=== Phenazopyridine ===

* Trade name: Pyridium
* '''Mechanism of action'''
** Unknown
* '''Pharmacology'''
** Rapidly excreted in the urine
* '''Efficacy'''
** Considered a “grandfathered” drug that lacks both the safety and efficacy data required for Food and Drug Administration approval[https://pubmed.ncbi.nlm.nih.gov/31006341/]
*** Marketed prior to the Food, Drug, and Cosmetic Act of 1938
* '''Contraindications (2)[https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=165d01d4-a9f7-2293-e054-00144ff8d46c&type=pdf]'''
** Hypersensitivity
** Renal insufficiency
* '''Adverse events[https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=165d01d4-a9f7-2293-e054-00144ff8d46c&type=pdf]'''
** Most common
*** Headache
*** Rash
*** Pruritis
*** Skin or sclera discoloration
**** A yellowish tinge of the skin or sclera may indicate accumulation due to impaired renal excretion and the need to discontinue therapy
*** Urine discoloration
**** Patients should be informed that phenazopyridine produces a reddish-orange discoloration of the urine and may stain fabric.
*** GI disturbance
** Rare but serious: methylglobinemia, hemolytic anemia, thrombocytopenia, neutropenia, nephrotoxicity, and hepatotoxicity, usually at overdosage levels
* '''Dosing'''
** 200 mg three times daily after meals
** Duration of treatment
*** When used concomitantly with an antibacterial agent for the treatment of a urinary tract infection, the administration of Phenazopyridine HCl should not exceed 2 days.'''[https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=165d01d4-a9f7-2293-e054-00144ff8d46c&type=pdf]'''
***American Hospital Formulary Service states that therapy may be extended for up to 15 days in non-infectious scenarios[https://pubmed.ncbi.nlm.nih.gov/31006341/]
***Another study found no difference in adverse drug reactions among patients receiving phenazopyridine for >14 days compared to a matched comparator group[https://pubmed.ncbi.nlm.nih.gov/31006341/]
***