Clinical Trial: Efficacy of Rapid Escalation of Cabergoline in Comparison to Conventional Dosing in Prolactin Secreting Macroadenomas.

Study Status: Recruiting
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Efficacy of Rapid Escalation of Cabergoline in Comparison to Conventional Dosing in Prolactin Secreting Macroadenomas.

Brief Summary: To study the effects of rapid escalation of Cabergoline in comparison to conventional dosing in macroprolactinomas. Rapid escalation of cabergoline may help in earlier normalization of prolactin and shrinkage of tumor mass, and thus decrease the cumulative dose of cabergoline altogether.

Detailed Summary:

The efficacy of cabergoline is dose related and determined by percentage of Dopamine 2 receptor occupancy and prolonged receptor affinity. Activation of membrane receptors and target cell responses is proportional to the degree of receptor occupancy. Greater the drug concentration, greater is the binding and receptor occupancy and greater is the efficacy of the drug. Receptor occupancy can be increased either by using high dose of cabergoline or by rapid escalation of cabergoline. The patients, who respond to increasing dosages of cabergoline, probably do so by increased receptor occupancy with higher doses.

Rapid escalation of doses of cabergoline is another approach to increase the drug concentration and increase the occupancy of the receptor. Earlier decrease in serum prolactin levels with rapid escalation may help in reducing the cumulative dose of cabergoline and total duration of treatment. Though studies with high doses of cabergoline have been performed in prolactinomas with normalization of prolactin levels in almost 100%, but systematic studies using rapid escalation of cabergoline in prolactinomas are lacking except the one by Bhansali et al. In their study, serum prolactin became normal in 93 per cent of the patients with a mean duration of 8.2 wk. The mean decrease in serum prolactin was 99 per cent by four weeks, however a similar decrease (93 to 99%) in prolactin was achieved in other studies with a time lag of 48 to 160 wk. This supports the notion that rapid hike in doses of cabergoline decreases serum prolactin levels faster and it becomes normal in the majority of patients earlier6. However it was an uncontrolled study with limited number of subjects.

Therefore present study was planned to study the efficacy of rapid escalation of Cabergoline versus conventional dosing in patients with macroprolactinomas
Sponsor: Postgraduate Institute of Medical Education and Research

Current Primary Outcome: Normoprolactinemia [ Time Frame: 1 year ]

Duration for normalization of serum prolactin and decrease in tumor volume >50 % from baseline.


Original Primary Outcome: Same as current

Current Secondary Outcome: Duration for resolution of Hypogonadism [ Time Frame: 1 year ]

Duration for resolution of hypogonadism in males as defined by normal serum total testosterone 9.9-27.8nmol/L and aging male study score(AMS). In females duration to acheive regular menstrual cycles.


Original Secondary Outcome: Same as current

Information By: Postgraduate Institute of Medical Education and Research

Dates:
Date Received: June 1, 2010
Date Started: May 2010
Date Completion: March 2012
Last Updated: June 11, 2010
Last Verified: May 2010