What antiemetic is best to use that does not prolong the QTc (QT interval corrected) interval?

From the Guidelines

Ondansetron (Zofran) is the best antiemetic option that does not significantly prolong the QTc interval, with a recommended dose of 4-8 mg orally or intravenously every 8-12 hours for adults and 0.1 mg/kg for children.

Key Considerations

• Ondansetron has minimal effects on the QTc interval at standard therapeutic doses, making it a safer choice compared to other antiemetics like domperidone or metoclopramide, which have more significant QT-prolonging effects 1.
• Other alternatives with negligible QTc effects include metoclopramide (Reglan) at 10 mg orally or intravenously every 6-8 hours, prochlorperazine (Compazine) at 5-10 mg orally or intravenously every 6-8 hours, scopolamine patches, and dimenhydrinate.
• It is crucial to consider the patient's complete medication list to avoid drug interactions that might additively prolong QTc, especially in patients with pre-existing cardiac conditions or electrolyte abnormalities 1.

Important Factors

• The risk of QT prolongation is a significant concern when selecting an antiemetic, as it can lead to potentially life-threatening arrhythmias like torsades de pointes 1.
• Certain medications, including antiarrhythmics, antipsychotics, and some antibiotics, can increase the risk of QT prolongation, and their use should be carefully evaluated in conjunction with antiemetic therapy 1.
• Patient-specific factors, such as female gender, hypokalemia, bradycardia, and congenital long QT syndrome, can also increase the risk of QT prolongation and should be taken into account when choosing an antiemetic 1.

From the Research

Antiemetic Options

• Ondansetron is a suitable option as it is not associated with QTc prolongation and is as effective as promethazine in relieving nausea and vomiting 2.
• 5-HT3-antagonists, such as ondansetron, appear to be a good alternative for the treatment of emesis in the emergency service 3.
• Amisulpride, a dopamine D2 and D3 antagonist, does not meaningfully prolong the QTc interval at doses effective for the management of postoperative nausea and vomiting 4.

Considerations

• Droperidol is effective but has a potential for QT prolongation, limiting its use to refractory cases 2.
• Metoclopramide and prochlorperazine must be monitored for akathisia, which can develop at any time over 48 hours post-administration 2.
• Dimenhydrinate is effective but can be contraindicated in emergency medicine due to its sedative effect 3.

Specific Antiemetics

• Ondansetron is a safe and effective option for most patient populations in the emergency department 2.
• Amisulpride, at a dose of 10 mg, does not have a clinically significant effect on the QT interval, even when coadministered with ondansetron 4.