Postoperative Pain and Morphine Consumption After Mastectomy - Lyrica

This study will compare the effects of oral pregabalin with placebo on postoperative pain and morphine usage after mastectomy. Pregabalin is an anticonvulsant agent approved by the United States Food and Drug Administration (FDA) for the treatment of neuropathic pain associated with post-herpetic neuralgia and diabetic neuropathy. Women 18-70 years of age, undergoing unilateral modified mastectomy or lumpectomy with axillary node dissection will be recruited to participate in the study. Patients unable to cooperative, those that have known allergy to pregabalin or morphine and a history of drug or alcohol abuse, chronic pain, history of daily intake of analgesics or steroids, or impaired kidney function will all be excluded from the study. A pregnancy test will also be performed to exclude pregnant women from the study. Oral pregabalin 300 mg (or placebo) will be administered to patients 1-2 hours before surgery followed by 150 mg 12 hours later. Thereafter, 150 mg of oral pregabalin (or placebo) will be administered twice daily until day 14. Whether a patient receives pregabalin or placebo will be decided based on a process similar to tossing a coin. Patients will receive a standard general anesthetic for their operation and will receive intravenous patient-controlled analgesia (PCA) morphine for pain in the immediate postoperative period. Oral opioids will be administered after discontinuation of the PCA. Subjects will be visited after the operation while in the hospital and intermittently for three months at the outpatient clinic after discharge from the hospital. Subjects will be asked to return remaining study drug/empty container when they are at the hospital for their 2 week follow up visit. Potential adverse effects of pregabalin include dizziness, somnolence, peripheral edema, weight gain, headache, dry mouth, blurry vision, and ataxia. The incidence of these side effects occurring ranges variously between 1 and 25%. Investigators will closely monitor all patients for the occurrence of these side effects.