DOUBLE-BLIND RANDOMIZED STUDY USING ORAL OR INJECTABLE BROMOCRIPTINE IN PATIENTS WITH HYPERPROLACTINEMIA

OBJECTIVE A new long-acting injectable form of bromocriptine has becom e available for long-term treatment of hyperprolactinaemic patients. T he objective of this study was to compare efficacy and tolerability of injectable and oral forms of bromocriptine. DESIGN A double-blind ran domized study. AII patients received either one injection of bromocrip tine 50 mg intramuscularly and placebo tablets for 28 days (Group A) o r one placebo injection and oral bromocriptine 7.5 mg daily for 28 day s (Group B). PATIENTS Twenty-three (12 patients for Group A and 11 pat ients for Group B) hyperprolactinaemia patients with (19 patients) or without (4 patients) CT/MRI evidence of tumour were studied. MEASUREME NTS Plasma PRL levels and serum bromocriptine levels were assessed dur ing a follow-up of 42 days. MRI and/or CT were evaluated before and 28 days after the beginning of the study. RESULTS All patients had signi ficant reductions of PRL levels from 1000 h and 1100 h of day 1 to 200 0 h of day 35. Normoprolactinaemia was shown in eight patients of Grou p A and six of Group B on days 1-28. Normal PRL levels were still pres ent in five patients of Group A and in one patient of Group B on day 3 5; only three patients of Group A had normoprolactinaemia on day 42. A significantly greater decrease in Group A in comparison with Group B was shown at 1200 h on day 1 and at all times as a percentage decrease from basal levels. Significantly higher levels of bromocriptine were shown in Group A at all timepoints studied. No difference was shown in tolerability and incidence of side-effects. CONCLUSION Our data show that injectable bromocriptine more frequently induced a prolonged norm oprolactinaemia than did the oral drug. Moreover, bromocriptine levels released during injectable bromocriptine were significantly higher th an during oral bromocriptine. On the other hand no difference was show n in the tolerability of bromocriptine according to the route of admin istration.