Cabergoline, sold under the brand name Dostinex among others, is a dopaminergic medication used in the treatment of high prolactin levels, , Parkinson's disease, and for other indications.
Cabergoline is an ergot derivative and a potent dopamine D2 receptor agonist.
Cabergoline was in 1980 and approved for medical use in 1993.
Medical uses
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Lactation suppression
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Hyperprolactinemia
[UK electronic Medicines Compendium Dostinex Tablets Last Updated on eMC Dec 23, 2013]
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Adjunctive therapy of prolactin-producing pituitary gland tumors ();
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Monotherapy of Parkinson's disease in the early phase;
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Combination therapy, together with levodopa and a decarboxylase inhibitor such as carbidopa, in progressive-phase Parkinson's disease;
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In some countries also: ablactation and dysfunctions associated with hyperprolactinemia (amenorrhea, oligomenorrhea, anovulation, nonpuerperal mastitis and galactorrhea);
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Treatment of uterine fibroids.
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Adjunctive therapy of acromegaly, cabergoline has low efficacy in suppressing growth hormone levels and is highly efficient in suppressing hyperprolactinemia that is present in 20-30% of acromegaly cases; growth hormone and prolactin are similar structurally and have similar effects in many target tissues, therefore targeting prolactin may help symptoms when growth hormone secretion cannot be sufficiently controlled by other methods;
Cabergoline is frequently used as a first-line agent in the management of prolactinomas due to its higher affinity for D2 receptor sites, less severe side effects, and more convenient dosing schedule than the older bromocriptine, though in pregnancy bromocriptine is often still chosen since there is less data on safety in pregnancy for cabergoline.
Off-label
Cabergoline has at times been used as an adjunct to
SSRI antidepressants as there is some evidence that it counteracts certain
adverse effect of those
drugs, such as reduced
libido and
anorgasmia. It also has been suggested that it has a possible
recreational use in reducing or eliminating the male refractory period, thereby allowing men to experience multiple ejaculatory orgasms in rapid succession, and at least two scientific studies support those speculations.
Additionally, a systematic review and meta-analysis concluded that prophylactic treatment with cabergoline reduces the incidence, but not the severity, of ovarian hyperstimulation syndrome (OHSS), without compromising pregnancy outcomes, in females undergoing stimulated cycles of in vitro fertilization (IVF).
Also, a study on rats found that cabergoline reduces voluntary alcohol consumption, possibly by increasing
GDNF expression in the ventral tegmental area.
It may be used in the treatment of restless legs syndrome.. Oral administration of cabergoline was faced with gastrointestinal problems which cause poor compliance in patients. One of the preferred solutions is to use non-oral dosage forms like suppositories. Vaginal suppositories have ease of use and could hinder gastrointestinal effects of cabergoline.
Pregnancy and lactation
Relatively little is known about the effects of this medication during pregnancy and lactation. In some cases the related
bromocriptine may be an alternative when pregnancy is expected.
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Pregnancy: available preliminary data indicates a somewhat increased rate of congenital abnormalities in patients who became pregnant while treated with cabergoline.. However, one study concluded that "foetal exposure to cabergoline through early pregnancy does not induce any increase in the risk of miscarriage or foetal malformation."
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Lactation: In rats cabergoline was found in the maternal milk. Since it is not known if this effect also occurs in humans, breastfeeding is usually not recommended if/when treatment with cabergoline is necessary.
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Lactation suppression: In some countries cabergoline (Dostinex) is sometimes used as a lactation suppressant. It is also used in veterinary medicine to treat false pregnancy in dogs.
Contraindications
Side effects
Side effects are mostly dose dependent. Much more severe side effects are reported for treatment of Parkinson's disease and (off-label treatment) for restless leg syndrome which both typically require very high doses. The side effects are considered mild when used for treatment of hyperprolactinemia and other endocrine disorders or gynecologic indications where the typical dose is one hundredth to one tenth that for Parkinson's disease.
Cabergoline requires slow dose titration (2–4 weeks for hyperprolactinemia, often much longer for other conditions) to minimize side effects. The extremely long bioavailability of the medication may complicate dosing regimens during titration and require particular precautions.
Cabergoline is considered the best tolerable option for hyperprolactinemia treatment although the newer and less tested quinagolide may offer similarly favourable side effect profile with quicker titration times.
Approximately 200 patients with newly diagnosed Parkinson's disease participated in a Clinical trial of cabergoline monotherapy.
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GI tract: Side effects were extremely frequent. Fifty-three percent of patients reported side effects. Very frequent: Nausea (30%), constipation (22%), and dry mouth (10%). Frequent: Gastric irritation (7%), vomiting (5%), and dyspepsia (2%).
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psychiatry disturbances and central nervous system (CNS): Altogether 51 percent of patients were affected. Very frequent: Sleep disturbances (somnolence 18%, insomnia 11%), vertigo (27%), and depression (13%). Frequent: dyskinesia (4%) and hallucinations (4%).
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Cardiovascular: Approximately 30 percent of patients experienced side effects. Most frequent were hypotension (10%), peripheral edema (14%) and non-specific edema (2%). Arrhythmias were encountered in 4.8%, palpitations in 4.3%, and angina pectoris in 1.4%.
In a combination study with 2,000 patients also treated with levodopa, the incidence and severity of side effects was comparable to monotherapy. Encountered side effects required a termination of cabergoline treatment in 15% of patients. Additional side effects were infrequent cases of hematology side effects, and an occasional increase in liver enzymes or Blood serum creatinine without Medical sign or symptoms.
As with other ergot derivatives, pleuritis, exudative pleura disease, pleura fibrosis, lung fibrosis, and pericarditis are seen. These side effects are noted in less than 2% of patients. They require immediate termination of treatment. Clinical improvement and normalization of X-ray findings are normally seen soon after cabergoline Drug withdrawal. It appears that the dose typically used for treatment of hyperprolactinemia is too low to cause this type of side effects.
Valvular heart disease
In two studies published in the
New England Journal of Medicine on January 4, 2007, cabergoline was implicated along with
pergolide in causing valvular heart disease.
As a result of this, the FDA removed pergolide from the U.S. market on March 29, 2007.
Since cabergoline is not approved in the U.S. for Parkinson's Disease, but for hyperprolactinemia, the drug remains on the market. The lower doses required for treatment of hyperprolactinemia have been found to be
not associated with clinically significant valvular heart disease or cardiac valve regurgitation.
Interactions
No
drug interaction were noted with levodopa or
selegiline. The drug should not be combined with other ergot derivatives. Dopamine antagonists such as
antipsychotics and
metoclopramide counteract some effects of cabergoline. The use of
antihypertensive drugs should be intensively monitored because excessive hypotension may result from the combination.
Pharmacology
Pharmacodynamics
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! Site
! Affinity
(Ki nM)
! Efficacy
(Emax %)
! Action |
| D1 | 214–32,000 | ? | Agonist |
| D2S | 0.5–0.62 | 102 | Superagonist |
| D2L | 0.95 | 75 | Partial agonist |
| D3 | 0.80–1.0 | 86 | Full agonist |
| D4 | 56 | 49 | Partial agonist |
| D5 | 22 | ? | Agonist |
| 5-HT1A | 1.9–20 | 93 | Full agonist |
| 5-HT1B | 479 | 102 | Superagonist |
| 5-HT1D | 8.7 | 68 | Partial agonist |
| 5-HT2A | 4.6–6.2 | 94 | Full agonist |
| 5-HT2B | 1.2–9.4 | 98 | Full agonist |
| 5-HT2C | 5.8–692 | 96 | Full agonist |
| 5-HT3 | >10,000 | – | – |
| 5-HT4 | 3,000 | ? | ? |
| 5-HT6 | 1,300 | ? | ? |
| 5-HT7 | 2.5 | ? | Antagonist |
| α1A | 288–>10,000 | 0 | Binder |
| α1B | 60–1,000 | ? | Binder |
| α1D | 166 | ? | Binder |
| α2A | 12–132 | 0 | Antagonist |
| α2B | 17–72 | 0 | Antagonist |
| α2C | 22–364 | 0 | Antagonist |
| α2D | 3.6 | ? | ? |
| H1 | 1,380 | ? | ? |
| M1 | >10,000 | – | – |
| SERT | >10,000 | – | – |
Notes: All sites are human except α2D-adrenergic, which is rat (no human counterpart). |
Cabergoline is a long-acting dopamine D2 receptor agonist. In-vitro rat studies show a direct inhibitory effect of cabergoline on the prolactin secretion in the of the pituitary gland and cabergoline decreases serum prolactin levels in reserpine rats. Although cabergoline is commonly described principally as a D2 receptor agonist, it also possesses significant affinity for the dopamine D3, and D4, serotonin 5-HT1A, 5-HT2A, 5-HT2B, and 5-HT2C, and α2-adrenergic receptors, as well as moderate/low affinity for the dopamine D1, serotonin 5-HT7, and α1-adrenergic receptors.[National Institute of Mental Health. PDSD Ki Database (Internet) cited. ChapelHill (NC): University of North Carolina. 1998-2013. Available from: ] Cabergoline functions as a partial agonist or full agonist at all of these receptors except for the 5-HT7, α1-adrenergic, and α2-adrenergic receptors, where it acts as an antagonist.
Ergot derivatives like cabergoline have been described as non- in spite of acting as serotonin 5-HT2A receptor agonists.
Pharmacokinetics
Following a single oral dose, resorption of cabergoline from the gastrointestinal (GI) tract is highly variable, typically occurring within 0.5 to 4 hours. Ingestion with
food does not alter its absorption rate.
Human bioavailability has not been determined since the drug is intended for oral use only. In
mice and
the absolute bioavailability has been determined to be 30 and 63 percent, respectively. Cabergoline is rapidly and extensively
metabolism in the
liver and excreted in
bile and to a lesser extent in
urine. All
metabolites are less active than the parental drug or inactive altogether. The human elimination
half life is estimated to be 63 to 68 hours in patients with Parkinson's disease and 79 to 115 hours in patients with
pituitary gland . Average elimination
half life is 80 hours. The metabolism of cabergoline is mediated by unidentified enzymes via a hepatic route and mainly consists of hydrolysis and oxidation by the alkylurea group and oxidation at the alkene.
History
Cabergoline was first synthesized by scientists working for the Italian drug company Farmitalia-Carlo Erba in
Milan who were experimenting with semisynthetic derivatives of the
ergot alkaloids, and a patent application was filed in 1980.
[ Council regulation (EEC) no 1768/92 in the matter of Application No SPC/GB94/012 for a Supplementary Protection Certificate in the name of Farmitalia Carlo Erba S. r. l.][ US Patent 4526892 - Dimethylaminoalkyl-3-(ergoline-8'.beta.carbonyl)-ureas] The first publication was a scientific abstract at the Society for Neuroscience meeting in 1991.
Farmitalia-Carlo Erba was acquired by Pharmacia in 1993,[Staff. News: Farmitalia bought by Kabi Pharmacia. Ann Oncol (1993) 4 (5): 345.] which in turn was acquired by Pfizer in 2003.[Staff, CNN/Money. April 16, 2003 It's official: Pfizer buys Pharmacia ]
Cabergoline was first marketed in The Netherlands as Dostinex in 1992.[ The drug was approved by the FDA on December 23, 1996.][ FDA approval history] It went generic drug in late 2005 following US patent expiration.
Society and culture
Brand names
Brand names of cabergoline include Cabaser, Dostinex, Galastop (veterinary), and Kelactin (veterinary), among others.
Research
Cabergoline was studied in one person with Cushing's disease, to lower adrenocorticotropic hormone (ACTH) levels and cause regression of ACTH-producing pituitary adenomas.
