Levorphanol (Levo-Dromoran) is an L-isomer morphi-nan derivative of morphine that is five to seven times more potent than morphine. It produces all of the side effects associated with morphine but less nausea. It is indicated for moderate to severe pain as a preoperative anxiolytic. It is often used in combination with thiopen-tal to reduce the latter drug’s anesthetic dose and to de-crease postoperative recovery time. The D-isomer of levorphanol, dextrorphan, does not possess opioid anal-gesic activity but is a useful antitussive.