Medical Treatment in Cushings Syndrome: Dopamine Agonists and Cabergoline

Dopamine (DA) is a catecholamine with a wide range of functions and whose five subtype receptors are found in different organs where they exert a mainly inhibitory action. Since this action may also appear in a number of secretory tumors in various locations, DA agonists have elicited some interest as a medical treatment for hypercorticism. Non-iatrogenic Cushing’s syndromes are due in 70% of the cases to a pituitary adrenocorticotropic hormone (ACTH)-producing adenoma, and, less frequently, to an adrenal adenoma or an ectopic ACTH secretion by a neuroendocrine tumor. First-line treatment in Cushing’s syndrome consists of the surgical removal of the secreting tumor. However, surgery may not achieve a complete cure in a number of cases, hence emphasizing the potential benefit of a medical complementary treatment, which could also benefit patients as an alternative approach, either when waiting for, or when the patient is not eligible for surgery. Studies of corticotropic adenomas have shown that 80% of these tumors express D2 receptors. Clinical trials of DA agonists in Cushing’s disease have shown an inhibitory effect of these drugs with an inhibition of ACTH secretion and/or a decrease of tumor size. There are only a Published online: September 10, 2010 Albert Beckers Endocrinologie, CHU Domaine Universitaire du Sart Tilman BE–4000 Liege (Belgium) Tel. +32 4 366 7083, Fax +34 4 366 7261, E-Mail albert.beckers @ chu.ulg.ac.be © 2010 S. Karger AG, Basel 0028–3835/10/09258–0116$26.00/0 Accessible online at: www.karger.com/nen D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /2 3/ 20 17 2 :4 4: 31 A M Dopamine Agonists in Cushing’s Syndrome Neuroendocrinology 2010;92(suppl 1):116–119 117 has not elicited a lot of interest from the endocrine community in comparison to other conditions like acromegaly. Medical treatment is, however, mandatory in some situations. Surgery may not be always curative. Sometimes patients’ general condition contraindicates surgery, which may be delayed, calling for a preparatory or secondary medical treatment. Historically, compounds interfering with the synthesis of cortisol were the main drugs used in these patients. Later, drugs interfering with the physiological control of hormone secretion have been tested in vitro or in vivo. Dopamine (DA) agonists are one of these new potential treatments [2] .