Previous studies have shown that the beta-adrenergic system plays a role in processing pain and the expression of hyperalgesia. Recent studies have investigated the analgesic effects, and potential anti-hyperalgesic effects (using a model of opioid induced (OIH) hyperalgesia) of propranolol, a beta adrenergic antagonist. We plan to further investigate the analgesic effects, and the potential anti inflammatory effects, of propranolol and compare those effects to alfentanil, an opioid of known effect, and placebo