Objective: Although an effective treatment for hyper-prolactinaemia, initiation of bromocriptine therapy may be associated with significant acute side-effects in some patients, particularly nausea, vomiting and postural hypotension. These may be minimized by initial treatment with i.m. depot bromocriptine (Parlodel-LAR, Sandoz, Basel, Switzerland), but adverse effects following the first injection may still be a significant problem. Following the observation that cortisol deficient patients were subject to an increased incidence of severe side-effects on initiation of bromocriptine therapy, we have evaluated whether concurrent administration of oral prednisolone to patients without cortisol deficiency might reduce adverse effects.
Design: Double-blind placebo-controlled trial with prednisolone (20 mg) prior to, and 16 hours after, depot injection of i.m. bromocriptine (50 or 100 mg).
Patients: Twenty-one consecutive patients with hyperprolactinaemia (serum prolactin > 1000 mU/l on 3 separate occasions) who were due to start depot bromocriptine and who had a normal cortisol response to insulin-induced hypoglycaemia.
Measurements: Symptoms at 0, 16 and 40 hours after injection were assessed using visual linear analogue scales and both inter and intra-group scores were compared by non-parametric tests.
Results: Depot bromocriptine was associated with the significant occurrence of light-headedness and lethargy in the placebo-administered group by 16 hours, and also with nausea and nasal congestion by 40 hours. These symptoms did not occur in the prednisolone-administered group.
Conclusions: Concurrent oral administration of prednisolone significantly reduces the incidence of acute adverse effects following depot bromocriptine. Two 20 mg doses of prednisolone given at 12-hour intervals may be used to avoid dopamine-agonist-induced adverse effects at the initiation of treatment with depot bromocriptine, and may also be of value in the treatment of side-effects associated with other dopamine agonist drugs.