Acromegaly--results of long term treatment with bromocriptine.

Bromocriptine, a long acting dopamine agonist, has been used to treat 73 patients with active acromegaly for between 3 and 25 months. Clear clinical improvement occurred in 71 patients (97%). This included improvement in facial appearance, reduction in hand and foot size and sweating, relief of headaches and increased energy and libido. Abnormal visual fields became normal in two patients, but one of these was given concomitant radiotherapy. A significant reduction in growth hormone occurred in 58 patients (79%), but only 15 patients had levels persistently below 5microgram/l. Carbohydrate tolerance improved with the reduction in growth hormone and of 23 patients with diabetes mellitus before treatment, glucose tolerance became normal in 15 and improved in a further 5. Administration of bromocriptine should begin slowly in order to minimise early side effects. Long term side effects have been minor to date and the deaths of two patients whilst taking the drug were not considered to have been caused by it. Bromocriptine offers a major advance in the management of acromegaly, but further careful follow-up is required to determine whether serious side effects will be a problem with the long term use of high doses.