Impaired prolactin response to hyperthermia in heroin addicts

The response of PRL, FSH and LH to sauna-induced hyperthermia was examined in 8 male former heroin addicts (studied after 14-24 days of abstinence) and 8 age- and sex-matched control subjects. The basal levels of PRL tended to be higher in former drug users than in control subjects (p = 0.07). After sauna, there were no changes in the addict group, whereas a significant increase was observed in normal subjects (p less than 0.001). Baseline plasma LH and FSH levels were significantly lower in former drug users (p = 0.02), but no change was found after sauna in either group. These findings are consistent with the existence of a deficient adaptation to thermal stress in chronic drug users, even after a relatively short drug-free period.