International Agency for Research on Cancer (IARC) - Summaries & Evaluations
PHENAZOPYRIDINE AND PHENAZOPYRIDINE HYDROCHLORIDE
VOL.: 24 (1980) (p. 163)
5. Summary of Data Reported and Evaluation
5.1 Experimental data
Phenazopyridine hydrochloride was tested in mice and rats by oral
administration and in mice by intraperitoneal administration. After
its oral administration in female mice, it significantly increased the
incidence of hepatocellular adenomas and carcinomas. In male and
female rats, it induced tumours of the colon and rectum.
Attention is drawn to the absence of studies on the mutagenicity
or teratogenicity of this compound.
5.2 Human data
Phenazopyridine hydrochloride is a weak urinary-tract analgesic and is
In one epidemiological study, involving a limited period of
observation, no association was observed between use of
phenazopyridine hydrochloride and any cancer.
There is sufficient evidence for the carcinogenicity of
phenazopyridine hydrochloride in experimental animals. The available
epidemiological data are insufficient to evaluate the carcinogenicity
of phenazopyridine hydrochloride to humans. In the absence of adequate
data in humans, phenazopyridine hydrochloride should be regarded, for
practical purposes, as if it presented a carcinogenic risk to humans.
For definition of the italicized terms, see Preamble Evaluation.
Previous evaluation: Vol. 8 (1975)
Subsequent evaluation: Suppl. 7 (1987)
Last updated: 7 April 1998