CV205–502, A NEW NON‐ERGOT DOPAMINE AGONIST, REDUCES PROLACTINOMA SIZE IN MAN

SUMMARY Seven patients with large prolactin‐secreting pituitary adenomas were treated for 8 weeks with once‐daily doses of the new, potent, non‐ergot, long‐acting dopamine agonist CV205–502. In five patients previous treatment with bromocriptine had failed to control their disease or been poorly tolerated and had therefore ceased. In all seven patients serum prolactin levels fell over the 8‐week period of CV205–502 treatment with the decrease ranging from 33 to 99%. Associated with this decline in prolactin all patients showed symptomatic improvement with two of the five women beginning to menstruate and the two patients with visual field impairment showing marked improvement. Tolerance of the drug, with doses at 8 weeks ranging from 0.075 to 0.3 mg, was excellent with only minimal and transient side‐effects being noted in three patients in none of whom was discontinuation of therapy necessary. In one patient non‐compliance after 6 weeks of therapy was associated with a rapid return of her serum prolactin towards pretreatment levels. In all seven patients the clinical and biochemical improvement was accompanied by a marked reduction in tumour size. Since the introduction of bromocriptine, an ergot alkaloid‐derived dopamine agonist (Thorner et al., 1980), into clinical practice in the early 1970s its role in the treatment of hyperprolactinaemic states has become well established (Besser et al., 1972). In patients with proved prolactin‐secreting pituitary adenomas (prolactinomas) the use of bromo‐criptine has been shown to be associated not only with suppression of prolactin secretion and restoration of gonadal function but also with reduction in adenoma size (McGregor et al., 1979). Bromocriptine is currently the treatment of choice for large prolactinomas (macroadenomas) (Vance and Thorner, 1987). Whilst the majority of patients with macroadenomas treated with bromocriptine show a decline in prolactin levels, in the