Induction of drug metabolism can be a homeostatic response.

The invasion of the body by toxic agents, in addition to the specific effects, causes a stereotype non-specific response -stress-, and an adaptive phenomenon like drug metabolism. Reserpine or hydrocortisone, causing a typical stress response, produce increased plasma concentrations of corticosterone in rats. -Here it is shown that corticosterone administration once, or for three days twice daily (200 mumoles/kg) increase body resistance to zoxazolamine, methyprylon, and tetraethylammonium bromide, reduce their plasma concentrations and augment zoxazolamine, hexobarbital, and aniline in vitro drug metabolism (9000 g liver supernatant). This constitutes a good evidence that drug metabolism can be induced in response to need.