Intrathecal neostigmine produces analgesia in animal and human and enhances systemic analgesia. This study was designed to examine postoperative analgesia with intrathecal neostigmine in a randomized double blinded trial with morphine control in patients undergoing classical vaginal repair and also to provide preliminary data on the interaction between these two drugs. The incidence of adverse effects was also assessed. We studied 80 female patients and they were divided into 8 groups , the first 3 groups received 50, 100 and 200 pg morphine intrathecally, the next 3 groups received 50 , 100 and 200 pg neostigmine intrathecally respectively, the fh group received saline intrathecally and the last group received 50 pg neostigmine and 50 pg morphine intrathecally. All of patients were anesthetized with general anaesthesia balanced techinque and stayed 24 hours in postanaesthesia care unit where adequacy of perioperative analgesia and side effects were assessed. Increasing doses of intrathecal morphine (50 - 100 - 200 microgram) and intrathecal neostigmine (50 - 100 - 200 microgram ) showed a dose-dependent pattern of analgesia (P< 0.005).The combination of neostigmine and morphine produce better analgesia and less adverse reaction than equi-analgesic dose of each drug given seperately. These data suggest that intrathecal neostigmine produce analgesia similar in duration to intrathecal morphine and that the combination of morphine and neostigmine may allow a reduction in the dose of each component for postoperative analgesia. |