Specific Substances: Theophylline
Nomination Date: 03/00/1980
Rationale: Theophylline was nominated by the NCI as part of a class study of purines. Pharmacologically, it acts as a smooth muscle relaxant & is used extensively to treat bronchial asthma and emphysema. Theophylline is structurally similar to two purines which induce sarcomas when injected into rats. It has not been adequately studied despite its wide spread use, possible genetic toxicity and reported teratogenicity and testicular toxicity.
NTP Principles: Pre 1993 - 6