Bromocriptine treatment in acromegaly: clinical and biochemical effects.

Eight selected patients with active acromegaly and elevated GH levels without other endocrine disturbances were submitted to long-term treatment and acute dose-response trials with bromocriptine. Seven patients showed clinical improvement and lowering of GH levels in response to long-term treatment, however, two of these showed only minor changes in GH levels during the acute dose-response trial. Glucose tolerance and heel pad thickness remained unchanged, while urinary hydroxyproline excretion and blood, plasma and erythrocyte volumes decreased. Using daily doses of 20 mg bromocriptine, side effects were generally minor. Severe vasovagal reactions were, however, observed in two patients, in one at the start of treatment, in the other after ingestion of 25 mg bromocriptine. Bromocriptine represents a valuable treatment alternative in acromegaly, but only long-term treatment will separate responders from nonresponders.