The influence of chronic administration of hypnotics and analgesics on rate of recovery from inhalation anesthesia in rats.

A series of groups of Sprague-Dawley rats were given either secobarbital, phenobarbital, morphine, pentazocine, diazepam, methotrimeprazine, or saline (control) intraperitoneally on 4 consecutive days and then, on day 5, anesthetized with chloroform, trichlorethylene, fluroxene, halothane, methoxyflurane, enflurane, isoflurane, bromotrifluorocyclobutane, or chlorotrifluorocyclobutane. One control group received neither pretreatment nor anesthetics and another was given pretreatment but no anesthetics. The factor of "enzyme induction" is also evaluated, as are SGPT elevation and liver and kidney lesions. If enzyme induction occurred with the drugs used for pretreatment, the anesthetics suppressed the expected response. SGPT levels were generally within normal range. The combinations of all pretreatments with enflurane, halothane, or methoxyflurane had the fastest recovery; recovery was slower with the other anesthetic agents, but none of the prior chemotherapeutic drugs accelerated recovery from the inhalation anesthetics.