Dopamine receptor agonists for treating prolactinomas

Abstract

Prolactinomas are the most common hormone-secreting pituitary tumours and cause infertility and gonadal and sexual dysfunction in both sexes. The approach to prolactinomas has changed in the last 25 years thanks to the availability of dopaminergic drugs characterised by a potent prolactin-inhibitory effect, a tumour shrinking effect associated with a satisfactory tolerability. In more recent years, cabergoline 1-[(6-allelylergolin-8beta-yl)carbonyl]-1-[3-(dimethylamino) propyl]-3-ethyl-urea an ergoline derivative with potent, selective and long-lasting inhibitory activity on prolactin release, has been used to suppress prolactin secretion in women with hyperprolactinaemia. Cabergoline was shown to be significantly more effective than bromocriptine in inducing a complete biochemical response and clinical efficacy and was better tolerated than bromocriptine in the majority of patients. Notable tumour shrinkage until tumour disappearance was observed during cabergoline treatment in most patients with macroprolactinoma and it was also proven effective in patients resistant to or with a poor response to bromocriptine. In view of the limited data on cabergoline-associated pregnancies and the long half-life of the drug, it is currently recommended that women hoping to become pregnant, once ovulatory cycles have been established, should discontinue cabergoline therapy 1 month before they intend to conceive. However, no data concerning negative effects on pregnancy or offspring have been reported. The great efficacy of this compound together with its excellent tolerability makes this drug the current treatment of choice for the majority of patients with hyperprolactinaemic disorders.

The effects of ergot and non-ergot-derived dopamine agonists in an experimental mouse model of endometriosis

“…Unlike Cb2, quinagolide is unlikely to affect cardiac valve tissue and, therefore, is not expected to induce proliferation of fibroblasts (Roth 2007) or regurgitation. In addition, quinagolide has a much shorter half-life (w17 h) than Cb2 (w63-69 h; Colao et al 2002), thus minimizing exposure during organogenesis for women who wish to become pregnant while under treatment with DRD2-A. Inducing a hyperprolactinemic state in the event of DRD2-A proving ineffective in the treatment of women with endometriosis may be ethically questionable.…”

Surgical outcomes and prognostic factors of transsphenoidal surgery for prolactinoma in men: a single-center experience with 87 consecutive cases

“…More recently, a meta-analysis showed that the proportion of patients with persisting normoprolactinemia after DA withdrawal was 21% in microprolactinomas and 16% in macroprolactinomas respectively, despite nearly all consisting of female prolactinomas (6). Furthermore, there are several other major drawbacks in DA including frequent side effects, extortionate price, and long-term administration (7)(8)(9). Some other studies have reported that drug resistance in males is remarkably more frequent relative to that in female patients (24-30 vs 5-18%) (10,11).…”

Management of resistant prolactinoma in infertile lady with successful maternal and perinatal outcome

“…3 Medical therapy with dopamine receptor agonists is the initial treatment of choice. 4,5 Cabergoline is more effective than bromocriptine and is considered as firstline agent as it has higher affinity for dopamine receptor binding sites with superior drug compliance and low incidence of side effects. 6,7 In our case, Cabergoline was started initially with 0.5 mg twice weekly and it was increased step wise to 3 mg per week.…”