And It's About Time There Was Some Support For Cushing's!
1 Oct 1999
by Troya Renee Yoder, used with permission
as originally posted on Suite 101.com, Pituitary
Disorders
Prolactinomas are generally responsive to pharmacological treatment. Unless the adenoma is especially large and pressing on vital structures, the treatment of choice is usually administration of a dopamine agonist. There are currently two medications available in the United States specifically indicated for the treatment of hyperprolactinemia: bromocriptine (Parlodel) and the more recently released Dostinex (cabergoline)
Dostinex (or cabergoline) is a long-lasting, oral dopamine-agonist specific for the D2 receptor indicated for the treatment of hyperprolactinemia. It became available in the United States by prescription in March 1997 and is manufactured by Pharmacia & Upjohn, Inc. Dostinex has proven very effective in lowering prolactin levels in most patients as well as decreasing tumor size. Dostinex is especially appealing because of its long half-life, resulting in once to twice weekly dosing
Until Dostinex became available in the U.S., the only other dopamine agonist approved for the treatment of prolactinomas and/or hyperprolactinemia was bromocriptine. However, Dostinex has proved to have a number of advantages over bromocriptine:
 | Lower incidence of side effects |
| | Twice weekly dosing versus 2-3 times daily for bromocriptine |
| | Generally more effective, especially in those in which bromocriptine was ineffective |
| | Dostinex is twice as expensive as bromocriptine |
| | Dostinex is not available in all countries |
| | Dostinex is not approved for use during pregnancy, and its effects on pregnancy are unknown at this time |
The side effects associated with Dostinex usually disappear or are reduced after a few doses. However, if you miss a dose, you may experience some of the original side effects for a short time. The most common side effects of Dostinex are:
| | Nausea |
| | Dizziness |
| | Sleepiness |
| | Headache |
| | Stuffy nose |
| | Webster et al., 1994. Comparison of cabergoline and bromocriptine in the treatment of hyperprolactinemic
amenorrhea. N Engl J Med 31: 904-909. |
459 women with either microprolactinoma or idiopathic hyperprolactinemia were treated with Dostinex or bromocriptine in a double blind study for eight weeks.
Results:
Attainment of normal prolactin levels: 83% on Dostinex 59% on Bromocriptine
Attainment of ovulatory cycles or pregnancy: 72% on Dostinex 52% on Bromocriptine
Return of monthly periods: 93% on Dostinex 84% on Bromocriptine
Dostinex had significantly less side effects with shorter duration and less severity that bromocriptine. Only 3% of women on Dostinex quit treatment because of side effects versus 12% that stopped treatment due to intolerance on bromocriptine.
| | Biller BMK, et al. 1996. Treatment of prolactin secreting macroadenomas with once weekly agonist cabergoline. J Clin Endocrinol Metab 81: 2338-2343. |
15 patients (8 women, 7 men) were treated with Dostinex, once weekly, for 48 weeks.
Results:
A 93.6% reduction in prolactin levels, with normal levels obtained in 73% of patients
5 patients who had previously been unable to achieve normal prolactin levels on other dopamine agonists, achieved normal prolactin levels on Dostinex gonadal function was restored in all hypogonadal men
75% of premenopausal women with amenorrhea experienced return of gonadal function
11 of 15 patients experienced tumor shrinkage
minimal side effects – no patients discontinued Dostinex because of intolerance
| | Colao, A. et al. 1997. Long-term and low-dose treatment with cabergoline induces macroprolactinoma shrinkage. J Clin Endocrinol Metab 82(11): 3574-3579. |
23 patients with macroprolactinomas
Results:
normalization of prolactin levels in 18 patients within 3-6 months at 0.5 mg/week
tumor volume reduction greater than 80% occurred in 61% of patients at the 12-24 month follow-up
the complete disappearance of the tumor occurred after 6 months in one patient and after 1 year of treatment in 5 patients
visual field defects were improved in 90% of patients who experienced them
In general, the data suggests that Dostinex is a better tolerated and a more effective dopamine agonist that bromocriptine in the treatment of prolactinomas. Dostinex effectively lowers prolactin levels and shrinks tumor size in a high percentage of cases, making it a good first option in the treatment of both micro- and macroprolactinomas.
Ciccarelli, E., Guisti, M., Miola, C., Potenzoni, F., Sghedoni, D., Camanni, F., and G. Giordano. 1989. Effectiveness and tolerability of long term treatment with cabergoline, a new long-lasting ergoline derivative, in hyperprolactinemic patients. J Clin Endocrinol Metab 69(4): 725-728
Cannavo, S., Curto, L., Squadrito, S., Almoto, B., Vieni, A., and F. Trimarchi. 1999. Cabergoline: a first-choice treatment in patients with previously untreated prolactin-secreting pituitary adenoma. J Endocrinol Invest 22(5): 354-359.
