Dostinex

Dostinex, also addressed as cabergoline, is known to be an ergot derivative and a potent dopamine receptor agonist on D2 receptors. Its main action lies in working on dopamine receptors in lactophilic hypothalamus cells to cause the suppression of prolactin production in the pituitary gland. It is quite often used as a second-line agent in the management of prolactinomas when bromocriptine stays ineffective in various treatments it is employed for.

Pharmacokinetics

The resorption of cabergoline from the gastrointestinal (GI) tract stays highly variable, occurring within 0.5 to 4 hours after the administration of a single dose. Ingestion with food does not alter its absorption rate and hence can be taken along with it as well. This drug has been intended for oral use only. The specialty of cabergoline lies in its ability to get quicklymetabolized in the liver and get excreted in the bile. However, most of the metabolites are less active than their parental drug or inactive altogether. The human elimination half-life in patients with Parkinson's disease consuming it is known to be estimated up to 63 to 68 hours and 79 to 115 hours in patients with pituitary tumors.

Indications

The function of cabergoline is seen to be very close to bromocriptine. Here are some areas where it is potentially employed:

• In the early phase of monotherapy of Parkinson's disease.
• It also finds it varied use in combination therapy of levodopa and a decarboxylase inhibitor such as carbidopa, in progressive-phase of Parkinson's illness.
• In the adjunctive therapy for prolactin-producing pituitary gland tumors known as prolactinomas.
• In few countries it is also used for ablactation and dysfunctions associated with hyperprolactinemia.
• Its usage by body builders to control gynecomastia caused by elevated prolactin levels through the use of anabolic steroids such as Nandrolone and Trenbolone has also been found.
• In many Phase III trials, it is seen to greatly reduce the risk of ovarian hyperstimulation syndrome (OHSS) in women undergoing stimulated cycles ofin vitro fertilization (IVF).

Pregnancy

Close to 100 women are seen to become became pregnant under cabergoline therapy with hyperprolactinemic conditions. The incidence ofspontaneous abortions and congenital abnormalities that studies have brought to light is usually comparable to non-treated patients. However, women wishing to become pregnant should wait for a span for atleast four weeks after the discontinuation of cabergoline therapy. Patients should keep in mind that its use should be immediately terminated soon after becoming pregnant.

Side effects

The possible sides effects of cabergoline administration were studied on patients newly diagnosed Parkinson's disease under cabergoline monotherapy, are as follows:

These side effects were mostly mild or moderate.

30% people suffered from nausea, 22% with constipation and 10% with dry mouth. Frequentc gastric irritation was seen to happen to 7% of patients, vomiting to 5% and dyspepsia to 2%.

A few affected with psychiatric disturbances were also tracked. Those whose central nervous system (CNS) was affected formed 51 percent of patients of the whole. Sleep disturbances (somnolence 18%, insomnia 11%), vertigo (27%), and depression (13%) were come common symptoms found to occur. Besides, 4% patients have been seen to be suffering from dyskinesia and hallucinations.

About 30 percent of patients experienced cardiovascular side effects. Of these, the most frequent were the ones suffering from hypotension, peripheraledema and non-specific edema.

Dosage

Cabergoline is most commonly used for the treatment of Parkinson’s disease. Hence its monotherapy includes an initial dose of 0.5 mg everyday. However, the usual maintenance dose is up to 2 to 4 mg daily. It is also used in combination therapy of 2 to 6 mg a day. In tumors of the pituitary gland and other hyperprolactinemic conditions, the dosage consists of 0.5 mg a week, slowly increased to 4.5 mg per week, if required.