Cabergoline in the long-term therapy of hyperprolactinemic disorders

Abstract

The efficacy and safety of the new long-acting dopamine agonist cabergoline were evaluated in 127 hyperprolactinemic patients (124F and 3M; 71 with microprolactinoma, 14 with macroprolactinoma, 5 with operated macroprolactinoma and 37 with idiopathic disorder) who were treated with the drug for from 3 to 52 months (median, 14 months). Cabergoline was administered orally at dose levels ranging between 0.2 and 3.5mg per week, given once weekly in 92 patients, twice weekly in 22, thrice weekly in 9 and daily in 4. Serum prolactin and progesterone levels, hematology, blood chemistry and electrocardiograms were frequently evaluated throughout treatment. CT or MR imaging of the pituitary was repeated during treatment in patients with macroprolactinoma and in 38 with microprolactinoma. After drug discontinuation, serum prolactin and gonadal function were evaluated monthly for three months in 65 patients and for up to two years in 12. Serum prolactin levels were normalized in 114 patients (90%). Of 56 women with amenorrhea, 52 resumed menses (with presumptive evidence of ovulation in 49); 17 women became pregnant; and sexual potency was restored in the 3 men. Evidence of tumor shrinkage was obtained in 13 of the 14 patients with macroprolactinoma and in 28 of 38 with microprolactinoma; complete disappearance of the tumor image was achieved in 2 macro and 14 microprolactinomas. A total of 48 adverse events was reported by 29 patients (2 3%), almost all typical of the pharmacological class and mild to moderate; no patient withdrew from treatment due to adverse events. Safety parameters did not change. Following cabergoline discontinuation, prolactin levels increased slowly, being still markedly lower than pretreatment values after three months; 10 patients out of 32 had persistently normal prolactin levels during one year of follow-up. Of 28 previously amenorrheic women who resumed menses during treatment and were followed for at least six months after cabergoline withdrawal, 23 continued to have cyclic ovulatory menses. These efficacy and safety data, including those obtained on drug withdrawal, compare favorably with those reported for bromocriptine and other prolactin-lowering drugs. Because of its very simple administration schedule, which should increase patient compliance, cabergoline may become the drug of choice for hyperprolactinemic disorders.