The Drug-Induced Respiratory Disease Website and App
Frequency - Incidence
Incidence of respiratory adverse event(s) due to the specific drug as assessed by number of reported/published cases in the literature. Red digits in stars indicate: 0 = Very rare, questionable signal · 1 = < 10 cases · 2 = 10-50 cases · 3 = 50–100 cases · 4 = 100-200 cases · 5 = >200 cases
Evidence level/grade
Evidence level for respiratory adverse event(s) due to the specific drug as estimated using Hill’s (1965), Naranjo’s (1981), and Bégaud’s (1985) criteria applied to published cases. Blue digits in stars indicate: 0 = Questionable · 1 = Low · 2 = Moderate · 3 = Robust · 4 = Definite · 5 = Unquestionable, pathognomonic
Methemoglobinemia
Publications
Phenazopyridine-Induced Methaemoglobinaemia The Aftermath of Dysuria Treatment.
European journal of case reports in internal medicine. 2022;9(2):003191
Acquired methemoglobinemia from phenazopyridine use.
International journal of emergency medicine. 2018;11(1):45
Chocolate-colored blood with normal artery oxygen: methemoglobinemia related to phenazopyridine.
The American journal of the medical sciences. 2011;341(4):337
Elderly woman with orange urine and purple hands.
Mayo Clinic proceedings. 2008;83(7):744
Methemoglobinemia due to ingestion of at most three pills of pyridium in a 2-year-old: case report and review.
The Journal of emergency medicine. 2003;25(2):143-8
Methemoglobinemia from overdose of phenazopyridine hydrochloride.
Annals of emergency medicine. 1980;9(3):147-9
Acquired methemoglobinemia and hemolytic anemia after usual doses of phenazopyridine.
Drug intelligence & clinical pharmacy. 1982;16(2):157-9