From the Guidelines
For patients with Long QT syndrome who need nausea medication, metoclopramide (Reglan) at 5-10 mg orally or IV every 6-8 hours as needed, is the safest option. This is because metoclopramide is a dopamine antagonist that works through a mechanism that doesn't significantly affect cardiac repolarization, thereby minimizing the risk of further QT prolongation that could trigger dangerous arrhythmias like Torsades de Pointes 1. Some key points to consider when treating nausea in Long QT patients include:
- Checking their current medication list for other QT-prolonging drugs, such as domperidone, which is known to prolong the QT interval and should be avoided 1
- Monitoring electrolytes (especially potassium and magnesium) to prevent hypokalemia and hypomagnesemia, which can increase the risk of QT prolongation and torsades de pointes 1
- Considering ECG monitoring during treatment if the patient has severe symptoms requiring IV medications, to quickly identify any potential QT prolongation or arrhythmias 1 Other relatively safe options for nausea medication in Long QT patients include prochlorperazine (Compazine) at 5-10 mg orally, IV, or IM every 6-8 hours, and antihistamines such as meclizine (Antivert) 25 mg every 4-6 hours or dimenhydrinate (Dramamine) 50-100 mg every 4-6 hours. It's also important to note that ondansetron (Zofran) should be avoided as it can prolong the QT interval, and that the goal is to effectively manage nausea while minimizing the risk of further QT prolongation that could trigger dangerous arrhythmias like Torsades de Pointes.
From the Research
Long QT Syndrome and Nausea Medication
- The risk of QTc prolongation with antiemetics in the palliative care setting has been reviewed, highlighting the need for careful consideration of patient-specific factors when choosing an antiemetic 2.
- Domperidone, a peripheral D2 dopamine receptor antagonist, has been shown to prolong the QT interval and may cause life-threatening arrhythmias, particularly when co-administered with QT-interacting medications 3.
- The management of long QT syndrome involves preventing the recurrences of torsades and includes intravenous magnesium and potassium administration, temporary cardiac pacing, and withdrawal of the offending agent 4.
- In the context of pain management, all major drug classes contain agents that increase the risk of QT prolongation, and slow dose titration and electrocardiography monitoring are recommended when the possible benefits of therapy outweigh the associated risks 5.
- A review of the safety of domperidone has highlighted the risk of QT prolongation and cardiac adverse effects, although the evidence suggests that domperidone does not appear to be strongly associated with QT prolongation at oral doses of 20 mg QID in healthy volunteers 6.
Medication Options
- Anticholinergics, antihistamines, antidopaminergics, 5-HT3 receptor antagonists, dronabinol, and medical marijuana are among the pharmacotherapy agents that may be used to control nausea and vomiting, but their associated risk of QTc prolongation must be carefully considered 2.
- Domperidone may be used to treat nausea, dyspepsia, and gastroparesis, but its use should be carefully monitored due to the risk of QT prolongation, particularly when co-administered with QT-interacting medications 3, 6.
Clinical Considerations
- A clinical treatment pathway is provided to help guide clinicians in choosing the most appropriate antiemetic based upon patient-specific factors for QTc prolongation 2.
- Electrocardiogram (EKG) evaluation before and during domperidone therapy is recommended to monitor for QT prolongation 3.
- Slow dose titration and electrocardiography monitoring are recommended when using medications that may increase the risk of QT prolongation 5.