Cabergoline, which appears to be as effective as bromocriptine in lowering prolactin levels and in reducing tumor size, has substantially fewer adverse effects than bromocriptine. Very rarely, patients experience nausea and vomiting or dizziness with cabergoline; they may be treated with intravaginal cabergoline as with bromocriptine. A gradually increasing dosage helps avoid the side effects on nausea, vomiting, and dizziness. Cabergoline at 0.25 mg twice per week is usually adequate for hyperprolactinemia with values less than 100 ng/mL. If required to normalize prolactin levels, the dosage can be increase by 0.25 mg per dose on a weekly basis to a maximum of 1 mg twice weekly.
Recent studies reveal an increased risk of cardiac valve regurgitation in patients with Parkinson disease who were treated with high doses of cabergoline or pergolide but not with bromocriptine (296, 297). Higher doses and a longer duration of therapy were associated with a higher risk of valvulopathy. It is postulated that 5HT2b-receptor stimulation leads to fibromyoblast proliferation (298). A recent cross-sectional study showed a higher rate of asymptomatic tricuspid regurgitation among cabergoline-treated patients compared to untreated patients with newly diagnosed prolactinomas as well as normal controls (299, 300).
The demonstrated relative safety of bromocriptine in reproductive-aged women and during more than 2,500 pregnancies suggests bromocriptine is the first choice for hyperprolactinemia and micro-and macro adenomas .
When bromocriptine or cabergoline cannot be used, other medications such as pergolide or metergoline may be used. In patients with a microadenoma who are receiving bromocriptine therapy, a repeat MRI scan may be performed 6 to 12 months after prolactin levels are normal, if indicated. Further MRI scans should be performed if new symptoms appear.
Discontinuation of bromocriptine therapy after 2 to 3 years may be attempted in a select group of patients who have maintained normoprolactinemia while on therapy , In cases of microadenoma induced prolacinaemia will raised PRL recur once the drug is cdiscontinute>?. Many reseracheers have shown that women treated with bromocriptine for a median of four yrs normoprolactinemia was sustained in 20% at a median follow-up of 40 months after treatment discontinuation .By contrast in case of cabergolin the discontinuation of cabergoline therapy was successful in patients treated for 3 to 4 years who maintained normoprolactinemia for longer time .In cabergoline discontinuers who met stringent inclusion criteria, a recurrence rate of 64% was noted , sustained normoprolactinemia in only a minority of patients (20%) after discontinuation.
Who are prone to recur hyperprolactinaemia?? Ans:-Patients with a) 2 years or more of therapy before discontinuation and b) no demonstrable tumor visible on MRI had the highest chance of persistent normoprolactinemia 3) Recurrence rates are higher for macroadenomas (as compared to microadenomas or hyperprolactinemia without adenoma) after cessation of bromocriptine or cabergoline. Such cases warrant close follow-up with serum prolactin and MRI after cessation or therapy. Warning:-In patients with macroadenomas, withdrawal of therapy should proceed with caution, as rapid tumor reexpansion may occur.
Macroadenomas
Macroadenomas are pituitary tumors that are larger than 1 cm in size. Bromocriptine is the best initial and potentially long-term treatment option, but transsphenoidal surgery may be required. High-dose cabergoline therapy was used in bromocriptine resistant or intolerant macroadenoma patients with success; however, cautions remain regarding the development of cardiac valve abnormalities (307).
Evaluation for pituitary hormone deficiencies may be indicated. Symptoms of macroadenoma enlargement include severe headaches, visual field changes, and, rarely, diabetes insipidus and blindness. After prolactin has reached normal levels following ergot alkaloid treatment, a repeat MRI is indicated within 6 months to document shrinkage or stabilization of the size of the macroadenoma. This examination may be performed earlier if new symptoms develop or if there is no improvement in previously noted symptoms.
Recent studies reveal an increased risk of cardiac valve regurgitation in patients with Parkinson disease who were treated with high doses of cabergoline or pergolide but not with bromocriptine (296, 297). Higher doses and a longer duration of therapy were associated with a higher risk of valvulopathy. It is postulated that 5HT2b-receptor stimulation leads to fibromyoblast proliferation (298). A recent cross-sectional study showed a higher rate of asymptomatic tricuspid regurgitation among cabergoline-treated patients compared to untreated patients with newly diagnosed prolactinomas as well as normal controls (299, 300).
The demonstrated relative safety of bromocriptine in reproductive-aged women and during more than 2,500 pregnancies suggests bromocriptine is the first choice for hyperprolactinemia and micro-and macro adenomas .
When bromocriptine or cabergoline cannot be used, other medications such as pergolide or metergoline may be used. In patients with a microadenoma who are receiving bromocriptine therapy, a repeat MRI scan may be performed 6 to 12 months after prolactin levels are normal, if indicated. Further MRI scans should be performed if new symptoms appear.
Discontinuation of bromocriptine therapy after 2 to 3 years may be attempted in a select group of patients who have maintained normoprolactinemia while on therapy , In cases of microadenoma induced prolacinaemia will raised PRL recur once the drug is cdiscontinute>?. Many reseracheers have shown that women treated with bromocriptine for a median of four yrs normoprolactinemia was sustained in 20% at a median follow-up of 40 months after treatment discontinuation .By contrast in case of cabergolin the discontinuation of cabergoline therapy was successful in patients treated for 3 to 4 years who maintained normoprolactinemia for longer time .In cabergoline discontinuers who met stringent inclusion criteria, a recurrence rate of 64% was noted , sustained normoprolactinemia in only a minority of patients (20%) after discontinuation.
Who are prone to recur hyperprolactinaemia?? Ans:-Patients with a) 2 years or more of therapy before discontinuation and b) no demonstrable tumor visible on MRI had the highest chance of persistent normoprolactinemia 3) Recurrence rates are higher for macroadenomas (as compared to microadenomas or hyperprolactinemia without adenoma) after cessation of bromocriptine or cabergoline. Such cases warrant close follow-up with serum prolactin and MRI after cessation or therapy. Warning:-In patients with macroadenomas, withdrawal of therapy should proceed with caution, as rapid tumor reexpansion may occur.
Macroadenomas
Macroadenomas are pituitary tumors that are larger than 1 cm in size. Bromocriptine is the best initial and potentially long-term treatment option, but transsphenoidal surgery may be required. High-dose cabergoline therapy was used in bromocriptine resistant or intolerant macroadenoma patients with success; however, cautions remain regarding the development of cardiac valve abnormalities (307).
Evaluation for pituitary hormone deficiencies may be indicated. Symptoms of macroadenoma enlargement include severe headaches, visual field changes, and, rarely, diabetes insipidus and blindness. After prolactin has reached normal levels following ergot alkaloid treatment, a repeat MRI is indicated within 6 months to document shrinkage or stabilization of the size of the macroadenoma. This examination may be performed earlier if new symptoms develop or if there is no improvement in previously noted symptoms.
No comments:
Post a Comment