Increased circulating levels of bromocriptine after vaginal compared with oral administration

Objective: To compare the circulating levels of bromocriptine after oral and vaginal administration of the drug. Design: Experimental. Participants: Seven ovulatory female volunteers and one hyperprolactinemic patient. Interventions: Ovulatory volunteers were randomized to receive either oral or vaginal bromocriptine (2.5 mg). In a second session, the subjects were crossed-over to bromocriptine by the alternate route. An additional hyperprolactinemic patient received vaginal bromocriptine only. Main Outcome Measure: Serum bromocriptine and prolactin (PRL) levels were measured hourly for 12 hours in the normal volunteers and for 10 hours in the hyperprolactinemic patient. Results: Circulating bromocriptine levels were significantly higher after vaginal bromocriptine after the 7th hour (P < 0.05). The reduction in serum PRL was significantly greater after oral administration between 2 and 6 hours. Conclusions: Vaginally administered bromocriptine may result in a reduction in the overall dose required, thereby improving compliance without compromising therapeutic efficacy.