Extrapyramidal reaction caused by ondansetron

Ondansetron-induced multifocal encephalopathy

We treated a patient who developed transient multifocal encephalopathy with extrapyramidal symptoms (oromandibular dystonia, oculogyric crisis, and limb dystonia) in temporal proximity to ondansetron administration on emergence from general anesthesia. No other medications known to cause extrapyramidal reactions were administered. Although these symptoms resolved fully, the presentation was dramatic and resembled the symptoms of structural brain injury. Ondansetron is used frequently as an antiemetic agent in many clinical settings and is not limited to surgical patients. Therefore, the entire medical community should be cognizant of this potential adverse reaction.

Extrapyramidal reactions to ondansetron: cross-reactivity between ondansetron and prochlorperazine?

IMPLICATIONS

Ondansetron can rarely induce extrapyramidal reactions in susceptible individuals. Our patient had a history of drug-induced dystonic reaction; therefore, these patients may be susceptible to extrapyramidal adverse reactions after ondansetron.

Ondansetron decreases vomiting associated with acute gastroenteritis: a randomized, controlled trial

OBJECTIVE

Relatively little research has examined the role of antiemetic agents in the treatment of acute gastroenteritis. The use of the selective 5-HT3 receptor antagonists (eg, ondansetron) offers a potentially valuable treatment option. The objective of this study was to evaluate the efficacy of ondansetron for the treatment of vomiting associated with acute gastroenteritis in children.

METHODS

A randomized, double blind, placebo-controlled trial was conducted in the emergency department of a tertiary-care children's hospital. Eligible patients were 1 month to 22 years old and required intravenous fluids for gastroenteritis. Of 172 patients approached, 107 were enrolled (54 to intravenous ondansetron, 53 to placebo). The mean age was 5.3 years, and 53% of the patients were male. The frequency of vomiting, admission rate, and occurrence of complications were measured.

RESULTS

After drug administration, 38 (70%) of the 54 patients in the ondansetron group had complete cessation of vomiting compared with 27 (51%) of the 53 patients in the placebo group. Sixteen (30%) of the 53 patients in the placebo group required admission compared with 14 (26%) of the 54 in the ondansetron group. An analysis of previously untreated patients with a measured serum carbon dioxide > or =15 mEq/L showed that 11 (23%) of the 47 who received placebo were admitted compared with 3 (7%) of the 43 who received ondansetron. No significant complications were detected.

CONCLUSIONS

Intravenous ondansetron decreases vomiting in children with gastroenteritis. In addition, ondansetron reduces the need for admission in those who are treated at an initial visit to the emergency department and have a measured serum carbon dioxide > or =15 mEq/L. The safety and low cost of this therapy suggests that ondansetron can be valuable in treating gastroenteritis in children.

Acute chorea due to ondansetron in an obstetric patient

This case describes a 34-year-old female who developed severe chorea following intravenous administration of ondansetron after elective caesarean section under spinal anaesthesia. A course of benztropine led to a decrease in severity of the reaction which resolved on the fifth postoperative day. Ondansetron is believed to cause extrapyramidal reactions through actions on 5HT 3 receptors in the basal ganglia. Whereas isolated case reports of extrapyramidal reactions to ondansetron do exist, they have typically been associated with higher doses and have resolved within hours. We report the lengthiest extrapyramidal reaction to ondansetron yet described.

The use of ondansetron in the treatment of nausea and vomiting associated with acetaminophen poisoning

BACKGROUND

Nausea and vomiting associated with poisoning can complicate treatment and in some cases delay potential antidote administration. Side effect such as lowering the seizure threshold may at times discourage the use of traditional phenothiazine and butyrophenone antiemetics.

METHODS

We performed a prospective, single arm, observational study examining the effectiveness of the 5HT3 receptor antagonist ondansetron in the management if nausea and vomiting associated with acetaminophen poisoning. Patients with a history or laboratory evidence of acetaminophen poisoning were eligible for inclusion in the study. Exclusion criteria included age less than 18 or greater than 65, use of other antiemetic therapy within the previous 12 hours, history of preexisting hepatic or hematologic disease, pregnancy, or significant ingestion of other substances. Upon meeting entry criteria, patients were administered 8 mg of intravenous ondansetron. Nausea was graded on a 100 mm scale with number of emetic episodes recorded before and after treatment.

RESULTS

Six patients were entered in the study. All patients had nausea and at least one emetic episode prior to ondansetron and prior to administration of N-acetylcysteine. All patients reported relief of nausea after ondansetron. The degree of nausea decreased by an average of 52% at 30 min and 88% at 60 min following ondansetron administration. No significant vital sign changes were recorded in any patient, and there were no complications related to therapy. Three patients were administered N-acetylcysteine, and all tolerated this therapy without vomiting after ondansetron.

CONCLUSIONS

Ondansetron appears to be a potentially useful adjunct in the management of nausea and vomiting associated with acetaminophen poisoning.