Anesthesia ondansetron

Parenteral Immediately before induction of anesthesia, or postoperatively if the patient experiences nausea or vomiting shortly after surgery, administer 4 mg undiluted IV in not less than 30 seconds, preferably over 2 to 5 minutes. Alternatively, 4 mg undiluted may be administered IM as a single injection in adults. In patients who do not achieve adequate control, administration of a second IV dose of 4 mg ondansetron postoperatively does not provide additional control of nausea and vomiting. 

Intravenous ondansetron (4 mg at induction of anesthesia and 0.13 mg with each 1 mg bolus of morphine) has been compared with intravenous droperidol (0.5 mg at induction and 0.05 mg with each bolus of morphine) in a double-blind trial in 142 patients (22). The two regimens had similar efficacy in the prevention of postoperative nausea and vomiting. The most important adverse effect was sedation significantly more patients given droperidol (15%) had excessive sedation than patients given ondansetron (5%). 

Dexamethasone is an effective prophylactic agent when administered either alone or in combination with other antiemetic drugs before the induction of anesthesia." Droperidol has been one of the most effective agents for PONV prophylaxis. At a dose of 1.25 mg IV, it was more effective and much less costly than combination therapy with ondansetron 4 mg TV and droperidol 0.625 mg TV." As discussed earlier, the recent FDA black box warning has effectively removed droperidol from clinical use. As a result of conflicting data. 

Comparative studies Azasetron versus ondansetron Intravenous azasetron 10 mg and ondansetron 8 mg have been compared in a double-blind, randomized trial in 98 patients with postoperative nausea and vomiting after gynecological laparoscopic surgery under general anesthesia [23 "]. Azasetron was more efficacious in the intermediate postoperative period (12-24 hours). Both drugs caused headache, dizziness, and constipation and the frequencies were similar. 

Nervous system A 26-year-old woman undergoing emergency cesarean delivery under spinal anesthesia with bupivacaine 10 mg was pre-medicated with intravenous ranitidine 50 mg and metoclopramide 10 mg, and received intramuscular diclofenac for postoperative analgesia [32 ]. Starting at 12 hours postoperatively she was given intravenous ondansetron 6 mg every 12 hours for nausea and vomiting. About 2 hours after the first dose she developed a severe headache, which persisted for over 90 hours and was characterized by aggravation of symptoms in coincidence with doses of ondansetron. The headache resolved completely a few hours after ondansetron withdrawal. 

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