الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 88 |  |  |
| | | from | 88 | | |
Abstract
Pruritus is an extremely bothersome side effect that frequently appears after intrathecal administration of opioids. This common side effect can be severe enough to be considered by the patient to be as bad or worse than the pain itself. Both prevention and treatments remain a challenge in the clinical management of these patients
The exact mechanism of how opioids induce pruritus is not precise. Many mechanisms have been proposed as the possible origin of the condition since there seems to be no single mechanism that can explain this phenomenon in all cases. Mechanisms that appear to be involved include the activation of the ”itch center” in the central nervous system, the medullary modulation through dorsal horn activation and the antagonism of the inhibitory transmitters of the descending pathways. Also, Inflammatory mediators such as bradykinin, serotonin, prostaglandins (PG), interleukins, and low pH have been shown to be effective in sensitizing peripheral nociceptors.
The most useful drugs are mu opioid antagonists, such as naloxone, and mixed opioids kappa agonists/mu antagonists, such as nalbuphine and butorphanol, the latter being capable of maintaining analgesia in addition to reduce itching. Some efficacy has also been observed, to a lesser extent, from 5-hydroxytryptamine 3 (5HT3) serotonin receptor antagonists, such as prophylactically administered ondansetron, and D2 dopaminergic receptor antagonists, such as droperidol. Moreover, propofol at subanesthetic doses, midazolam, and prophylaxis with mirtazapine and oral gabapentin have been used with efficacy.
In this study, we compared the efficacy of prophylactic preoperative administration of oral gabapentin versus metoclopramide for prevention of opioid induced pruritus in spinal anesthesia.
The results of the study showed that Gabapentin is as effective as Metoclopramide in prevention of opioid induced pruritus in spinal anesthesia. But, Gabapentin was found to be slightly more effective in reducing the severity of pruritus than Metoclopramide
Furthermore, Metoclopramide showed more effectiveness in prevention of post spinal nausea and vomiting. Both drugs showed no effect on hemodynamics or urinary retention incidence.