Bromocriptine in severe adult asthma--a negative report.

A pilot study had suggested that bromocriptine (a dopamine agonist) might be of benefit in severe asthma, particularly in patients with marked diurnal variation in peak flow. Two studies are reported: (1) a longterm double-blind, controlled trial comparing bromocriptine (B) with placebo (P) in patients with severe asthma and, (2) a withdrawal study in patients who had received known bromocriptine, with apparent benefit, for at least one year. Of 27 patients (16B, 11P) admitted to the double-blind trial only eight (4B, 4P) completed 52 weeks on the trial drug as nine (6B, 3P) had been withdrawn for side-effects, eight (4B, 4P) for failure and two (2B) for both reasons. The results, based on changes in steroid dosage and other medication, daily symptom scores and PEF values, suggest that bromocriptine has little effect in asthma. In addition side-effects were frequent and troublesome. In the withdrawal study, ten patients who had been taking bromocriptine for a year or more were switched to an indistinguishable placebo if their asthma was considered to be stable. The results, of this second study, support the conclusion of the double-blind study, that bromocriptine has little beneficial effect in asthma.