Prolactinoma medical therapy: Difference between revisions
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Medical therapy for prolactinoma includes dopamine agonists. Dopamine is the chemical that normally inhibits prolactin secretion. | Medical therapy for prolactinoma includes dopamine agonists. Dopamine is the chemical that normally inhibits prolactin secretion. | ||
'''Bromocriptine''' (Parlodel) | '''[[Bromocriptine]]''' (Parlodel) | ||
*Dosage | *Dosage | ||
A typical starting dose is one-quarter to one-half of a 2.5 milligram (mg) tablet taken at bedtime with a snack. The dose is gradually increased every 3 to 7 days as needed and taken in divided doses with meals or at bedtime with a snack. Most people are successfully treated with 7.5 mg a day or less, although some people need 15 mg or more each day. Because bromocriptine is short acting, it should be taken either twice or three times daily. | A typical starting dose is one-quarter to one-half of a 2.5 milligram (mg) tablet taken at bedtime with a snack. The dose is gradually increased every 3 to 7 days as needed and taken in divided doses with meals or at bedtime with a snack. Most people are successfully treated with 7.5 mg a day or less, although some people need 15 mg or more each day. Because bromocriptine is short acting, it should be taken either twice or three times daily. | ||
'''Cabergoline''' (Dostinex) | '''[[Cabergoline]]''' (Dostinex) | ||
Cabergoline is a newer drug that may be more effective than bromocriptine in normalizing prolactin levels and shrinking tumor size. Cabergoline also has less frequent and less severe side effects. Cabergoline is more expensive than [[bromocriptine]] and, being newer on the market, its long-term safety record is less well defined. | Cabergoline is a newer drug that may be more effective than bromocriptine in normalizing prolactin levels and shrinking tumor size. Cabergoline also has less frequent and less severe side effects. Cabergoline is more expensive than [[bromocriptine]] and, being newer on the market, its long-term safety record is less well defined. | ||
*Dosage | *Dosage | ||
Revision as of 15:00, 10 September 2015
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Faizan Sheraz, M.D. [2]
Overview
Medical therapy for prolactinoma includes dopamine agonists. Dopamine is the chemical that normally inhibits prolactin secretion. The goal of treatment is to:
- Return prolactin secretion to normal
- Reduce tumor size
- Correct any visual abnormalities
- Restore normal pituitary function
As mentioned above, the impact of stress should be ruled out before the diagnosis of prolactinoma is given. Exercise can significantly reduce stress and, thereby, prolactin levels. It should also be noted that higher prolactin levels may contribute to the development of prolactinomas so the diagnosis can be self-fulfilling if the original cause is stress. In the case of very large tumors, only partial reduction of the prolactin levels may be possible.
Medical Therapy
Medical therapy for prolactinoma includes dopamine agonists. Dopamine is the chemical that normally inhibits prolactin secretion.
Bromocriptine (Parlodel)
- Dosage
A typical starting dose is one-quarter to one-half of a 2.5 milligram (mg) tablet taken at bedtime with a snack. The dose is gradually increased every 3 to 7 days as needed and taken in divided doses with meals or at bedtime with a snack. Most people are successfully treated with 7.5 mg a day or less, although some people need 15 mg or more each day. Because bromocriptine is short acting, it should be taken either twice or three times daily.
Cabergoline (Dostinex) Cabergoline is a newer drug that may be more effective than bromocriptine in normalizing prolactin levels and shrinking tumor size. Cabergoline also has less frequent and less severe side effects. Cabergoline is more expensive than bromocriptine and, being newer on the market, its long-term safety record is less well defined.
- Dosage
The usual starting dose is .25 mg twice a week. The dose may be increased every 4 weeks as needed, up to 1 mg two times a week. Cabergoline should not be stopped without consulting a qualified endocrinologist. Recent studies suggest prolactin levels are more likely to remain normal after discontinuing long-term cabergoline therapy than after discontinuing bromocriptine. These drugs shrink the tumor and return prolactin levels to normal in approximately 80 percent of patients. Both drugs have been approved by the U.S. Food and Drug Administration for the treatment of hyperprolactinemia. Bromocriptine is the only dopamine agonist approved for the treatment of infertility. This drug has been in use longer than cabergoline and has a well-established safety record. Because limited information exists about the risks of long-term, low-dose cabergoline use, generally the lowest effective dose is prescribed and periodically the need for continuing therapy is reassessed. People taking cabergoline who develop symptoms of shortness of breath or swelling of the feet should promptly notify their physician because these may be signs of heart valve damage[1].
- Side Effects
Nausea and dizziness are possible side effects of bromocriptine. To avoid these side effects, bromocriptine treatment must be started slowly.In people taking cabergoline or bromocriptine to treat Parkinson's disease at doses more than 10 times higher than those used for prolactinomas, heart valve damage has been reported. Rare cases of valve damage have been reported in people taking low doses of cabergoline to treat hyperprolactinemia. Before starting these medications, the physician will order an echocardiogram.
Prolactinoma and Pregnancy
A woman with a prolactinoma should discuss her plans to conceive with her physician, so she can be carefully evaluated prior to becoming pregnant. This evaluation will include a magnetic resonance imaging (MRI) scan to assess the size of the tumor and an eye examination with measurement of visual fields. As soon as a patient is pregnant, her doctor will usually advise that she stop taking bromocriptine or cabergoline, the common treatments for prolactinoma. Most endocrinologists see patients every two months throughout the pregnancy. The patient should consult her endocrinologist promptly if she develops symptoms--particularly headaches, visual changes, nausea, vomiting, excessive thirst or urination, or extreme lethargy. Bromocriptine or cabergoline treatment may be renewed and additional treatment may be required if the patient develops symptoms from growth of the tumor during pregnancy. At one time, oral contraceptives were thought to contribute to the development of prolactinomas. However, this is no longer thought to be true. Patients with prolactinoma treated with bromocriptine or cabergoline may also take oral contraceptives. Similarly, post-menopausal estrogen replacement is safe in patients with prolactinoma treated with medical therapy or surgery.