Rationale: Few studies have systematically determined whether the response to cocaine in human females is related to hormonal fluctuations at different phases of the menstrual cycle.
Objectives: To investigate the responses to repeated doses of smoked cocaine in women during two phases of the menstrual cycle using a within-subject design.
Methods: Eleven non-treatment seeking female cocaine smokers were administered smoked cocaine during the follicular and mid-luteal phases of the menstrual cycle. The order of menstrual cycle phase was counterbalanced across women and the order of cocaine doses was randomized. During each phase, there were four cocaine administration sessions. During each session, participants could smoke up to six doses of cocaine (either 0, 6, 12, or 25 mg cocaine base, depending on the session) at 14-min intervals.
Results: The number of cocaine doses administered did not vary between the follicular and luteal phases. After cocaine administration, heart rate and several ratings - such as "good drug effect", "high", "stimulated", and "drug quality ratings" - were increased more during the follicular phase than the luteal phase, although, for some measures, these effects varied based on the cocaine dose. Further, dysphoric mood during the luteal phase was improved after cocaine administration.
Conclusions: These results indicate that the cardiovascular and subjective effects of repeated doses of smoked cocaine are complex and vary as a function of menstrual cycle phase and cocaine dose.