Background: Pruritus is the most distressing symptom in hemodialysis patients. Its etiology has not yet been delineated thus, there are no good therapeutic options. Serotonin has been reported to be a mediator of uremic pruritus while ondansetron is a potent and selective inhibitor of 5-HT3 receptors. The aim of this study was to evaluate the effect of ondansetron on uremic pruritus in hemodialysis patients.

Materials and Methods: In this randomized double-blind clinical trial, 70 patients undergoing hemodialysis with moderate and severe itching were enrolled. They were randomly divided into two groups: one group received ondansetron 8 mg three times daily and the other group was given loratadine 10 mg two times a day for 2 weeks. Pruritus scores were recorded by the patients and the mean scores were compared before and after intervention.

Results: Changes in VAS scores after treatment with ondansetron and loratadin were both significant (p=0.001), but the difference between ondansetron and loratadin was not significant (p=0.8).

Conclusion: The results showed that ondansetron was as effective as loratadin in controlling renal itch.

Background: Caesarean section is one of the most common gynecologic surgeries. Nausea and vomiting after pain is the most common side effect of surgeries, today, we most widely use of serotonin receptor antagonists, that are most effective antiemetic and have less side effect rather than other drug. Ondansetron is typical serotonin antagonists.

Materials and Methods: This is a randomized, double-blind clinical trial on 162 women undergoing cesarean section. 4mg intravenous ondansetron was given to first group and 8mg oral ondansetron was given to second group and thired group recived placebo. Blood pressure and heart rate were measured before and immediately after performing spinal and every 5 minute until 20 minute. Post operative nausea and vomiting and APGAR score were recorded after operation in recovery and 2, 4, and 6 houres after surgery.

Results: There was no significant difference among 3 groups according to age, gravidity, mean atrial pressure and heart rate before and during surgery. Nausea and vomiting in oral and intravenous groups at recovery, 2 and 4 hours after surgery were significantly less nausea and vomiting than placebo group (p<0.05). Whereas there was no significant difference between oral and intravenous groups.

Conclusion: It was concluded that using oral ondansetron with the same antiemetic effect is more convience to women undergoing cesarean section with spinal anesthesia.

Background: Spinal anesthesia is an efficient method of providing intra operative analgesia and a safe alternative to general analgesia in many cesarean patients. Despite its advantages, SA is not free from adverse effects, which include unwanted cardiovascular events, in most cases: hypotension and bradycardia. Ondansetron is a 5HT3 receptor antagonist, with known efficacy on preventing nausea and vomiting. Maybe ondansetron given intravenously attenuates the fall of blood pressure and heart rate, by 5HT3 blocking in vagal nerve endings and effect on BJR.(Bezold jarish Reflex).

Materials and Methods: In this clinical trial 102 healthy pregnant women that were candidate for elective cesarean in hamedan fatemieh hospital during 3 months in 1390, studied. They were randomized into 2 groups: the ondansetron group, n= (51) received (4miligram) ondansetron intravenously before performing spinal anesthesia, and placebo group n= (51): received 2cc sterile water before spinal anesthesia. Spinal anesthesia was performed with hyperbaric bupivacaine (0.5%) 10 mg and sufentanil (5 µg) BP and HR were measured and recorded before and after anesthesia immediately. If hypotension happened, ephedrine 5- 10mg injected. Itching and nausea recorded every 10 min during operation by observation and question.

Results: There were no significant differences in SBP, DBP, MAP, HR and itching in both groups. Nausea and vomiting ,and mean consumed ephedrine was siginificantly different in both groups.(p=0.001, p=0.009).

Conclusion: Ondansetron given intravenously with antiemetic dose (4miligram), decreases mean consumed ephedrine and nausea and vomiting after spinal anesthesia, but doesn't have an influence on BP, HP and pruritus

Background: The aim of this study was to compare the efficacy of ondansetron, Midazolam and metoclopramide with placebo in preventing PONV following strabismus surgery.

Material and Methods: 160 patients were allocated with simple randomization in 4 groups of 40: group ON received Ondansetrone 0.05mg/kg, MT group received Metoclopramide 0.15mg/kg, MD group received Midazolam 0.03mg/kg intravenously and group CT received the solution of NaCl 0.9% as placebo infused with the same volume and the same manner 30 minutes before the end of surgery. The patients were evaluated for nausea, vomiting, need and  dosage of anti-emetic drugs, time of liquid and solid diet tolerance, drug complications and satisfaction score for the initial 24 hours after anesthesia.

Results:  The frequency of nausea (p-value = 0.001< 0.05) and vomiting (p-value=0.084>0.05) was lower in ON group and both of these complications were lower in MD group compared with MT and CT group. Use of rescue antiemetic was higher in MT and CT group (p-value = 0.001 < 0.05). Patient satisfaction was higher in ON group compared with other 3 groups (p-value=0.001<0.05).

Conclusion:   Prophylactic use of Ondansetron is more effective with fewer side effects than Metoclopramide and Midazolam in the prevention of PONV following strabismus surgery. Furthermore, metoclopramide was less effective and was associated with more adverse effects.