From the Guidelines
The best treatment for nausea in patients with prolonged QT interval (QTc) is ondansetron or granisetron, 5-Hydroxytryptamine3 (5-HT3) receptor antagonists, as they are effective in improving nausea and vomiting without significant risks of QT prolongation.
Treatment Options
- 5-HT3 receptor antagonists: ondansetron and granisetron are effective in decreasing symptom scores by 50% in patients with refractory gastroparesis symptoms 1.
- Dosing: ondansetron is available in both parenteral and enteral forms, while granisetron is available as a liquid, tablets, and a transdermal patch, with a recommended dose of 3.1 mg/24 h for the transdermal patch 1.
Rationale
- QT prolongation risk: domperidone, a dopamine D2-receptor antagonist, has a risk of QT prolongation and ventricular tachycardia, making it a less favorable option for patients with prolonged QTc 1.
- Efficacy: 5-HT3 receptor antagonists have similar efficacy and can be selected based on price, availability, and mode of delivery 1.
- Alternative options: neurokinin (NK-1) receptor antagonists, such as aprepitant, may also be effective in improving nausea and vomiting, but their use may be limited by cost and availability 1.
From the Research
Treatment Options for Nausea in Patients with Prolonged QT Interval (QTc)
- The treatment of nausea in patients with prolonged QT interval (QTc) requires careful consideration of the potential effects of antiemetic drugs on the QT interval 2, 3, 4, 5, 6.
- Ondansetron, a commonly used antiemetic, has been shown to prolong the QT interval in various studies 2, 3, 4, 5.
- A study found that a single intravenous dose of ondansetron induced QT prolongation in adult emergency department patients, with a higher risk of QTc prolongation associated with 8 mg doses compared to 4 mg doses 2.
- Another study compared the effects of droperidol and ondansetron on QTc interval prolongation in patients with postoperative nausea and vomiting, and found that both drugs induced similar clinically relevant QTc interval prolongations 3.
- A meta-analysis found that the administration of ondansetron was associated with a statistically significant prevalence of QT prolongation in all age groups, particularly among patients older than 18 years of age 4.
- A study evaluated the effect of different doses of intravenous ondansetron on QT interval prolongation in the prophylaxis of postoperative emesis, and found that 1 mg of ondansetron caused no or insignificant prolongation of the QTc interval 5.
- In the intensive care unit, patients are particularly prone to experience QTc interval prolongation due to exposure to certain drugs and underlying clinical conditions, highlighting the need for close monitoring and evaluation 6.
Considerations for Treatment
- When treating nausea in patients with prolonged QT interval (QTc), it is essential to consider the potential risks and benefits of different antiemetic drugs 2, 3, 4, 5, 6.
- The choice of antiemetic drug and dosage should be individualized based on the patient's underlying medical conditions, age, and other factors that may affect the QT interval 2, 3, 4, 5.
- Close monitoring of the QT interval and electrocardiographic recordings is recommended when administering antiemetic drugs to patients with prolonged QT interval (QTc) 2, 3, 6.