Cabergoline for the Treatment of Chronic Pain Due to Endometriosis

Inclusion Criteria: * Female with surgically-confirmed endometriosis * Age 15 years to 40 years * Current use ≥ 2 months duration of hormonal therapy such as combined oral contraceptives, norethindrone acetate, or levonorgestrel intrauterine device * Current pelvic pain (score ≥ 3 on Visual Analog Scale, where 0 represents absence of pain and 10 indicates unbearable pain) present for ≥ 14 days/month over the 2 months prior to study enrollment * Willingness to comply with visit schedule and protocol Exclusion Criteria: * Pre-menarche or post-menopause * Contraindications to cabergoline (e.g., cardiac valve disorder; pulmonary, pericardial, retroperitoneal fibrotic disorder; hypersensitivity to ergot derivatives; uncontrolled hypertension) * Significant mental or chronic systemic illness that might confound pain assessment or the ability to complete the study * Pregnant, breastfeeding, or planning to become pregnant in the next 6 months * Impaired liver function (ALT \> 2x normal) or liver disease * Breast cancer, current or previous * Thromboembolic disease, current or previous * Use of other drugs that affect dopamine (e.g., phenothiazines, metoclopramide, butyrophenones)