Background: Intrathecal morphine side effect is Nausea & Vomiting after surgery. The aim of the study was to evaluate the effect of intrathecal atropine on PONV in patients receiving intrathecal morphine in lower limb surgeries.

Materials and Methods: In this clinical trial , 120 patients undergoing lower limb surgery were randomly divided into 2 groups . Experimental group received 0.1 mg (1cc) Intrathecal atropine and control group received 1cc saline 0.9% . PONV during the first 24 hours and hemodynamic changes in minute 3, 5, 10 and 15 after surgery in both groups were measured. Data were analyzed using SPSS software (verision14). independent t-test, repeated measures manova,and chi-square were used to compare comparison of variables.

Results: Hemodynamic cheanges before injection and 3, 5, 10 and 15 after injection in two groups was not significant (P>0.05). None of the patients in the intervention group were PONV, but 17 patients in the control group had PONV that this difference was statistically significant (p =0.000 ). Pain in the control group was great than intervention group while 26 patients in the control group and 14 patients in the intervention group had vas greater than 3 that this difference was statistically significant( P = 0.04).

Conclusion: Intrathecal atropine without interfering Hemodynamic and pain relief prevent nausea and vomiting caused by Intrathecal morphine in patients undergoing surgery to the lower limbs..

Background: It is well known that morphine influence learning and memory processes. The Nucleus accumbens (N.ac) which has an important role in reward participates in morphine-induced impairment of memory retention. Considering the cholinergic system is involved in the effects of morphine on learning and memory, in the present study, the effects of intra-N.ac injections of acetylcholine receptor antagonists alone or with morphine on memory retention and morphine-induced memory has been investigated in rats.

Materials and Methods: In this original research animals were bilaterally cannulated in the N.ac and a step-through passive avoidance task was used for the assessment of memory retention .

Results: Post-training subcutaneous administration of morphine dose dependently decreased the learning and induced amnesia. The administration of the same dose of morphine as pre-test treatment induced state-dependent learning. Pre-test intra- N.ac administration of atropine, scopolamine and mecamylamine in different doses alone cannot affect on memory retention. While, pretest intra- N.ac injection of these drugs before the administration of morphine dose dependently inhibited morphine state-dependent learning. The level of statistical significance was set at p<0.05 .

Conclusion: The processes of learning in animals can be affected by morphine and the opioids produce state-dependent learning. Moreover, it can be concluded that inactivation of the muscarinic and nicotinic acethylcoline receptors in the N.ac are involved in mediating morphine state-dependent learning.