[Prolactin stimulation using the metoclopramide test in females taking oral contraceptives]

In 31 patients taking oral contraceptives (o.c.) for a period between 1 year to more than 3 years, basal serum prolactin levels and metoclopramide induced prolactin values were determined 30 and 60 minutes following an i.v. injection of 10 mg of metoclopramide. The basal prolactin levels were elevated in 7 women to more than 1,000 mU l. The 3 groups of patients taking o.c. with different estrogen doses showed higher drug induced increase of their prolactin levels than the controls. These differences were statistically significant between groups I and III and the control group. No differences could be found between the challenged values of the users groups. The prolactin increase challenged with 200 micrograms TRH in 5 women under o.c. was considerably smaller than that observed in the metoclopramide groups, but exceeded the TRH induced levels found in the controls. The significance of these findings is discussed with special reference to the promotion of prolactinomas.