From the Guidelines
Metoclopramide (Reglan) is associated with a risk of QT interval prolongation, particularly at higher doses or in patients with other risk factors, and should be used with caution in these populations. While the risk is considered low, there have been rare reports of QT interval prolongation associated with its use, particularly with intravenous administration 1. The mechanism behind this potential effect involves the drug's impact on cardiac ion channels, particularly potassium channels that regulate cardiac repolarization. Patients with pre-existing cardiac conditions, electrolyte abnormalities (especially low potassium or magnesium), or those taking other medications known to prolong the QT interval should use metoclopramide with caution.
Key Considerations
- The risk of QT prolongation appears to be dose-dependent and is more likely to occur with intravenous administration than with oral dosing.
- Healthcare providers typically monitor higher-risk patients more closely when prescribing metoclopramide.
- If a patient experiences symptoms like palpitations, dizziness, or fainting while taking metoclopramide, they should seek medical attention promptly as these could potentially indicate cardiac rhythm disturbances related to QT prolongation.
Relevant Guidelines
- The British Thoracic Society guidelines mention metoclopramide as an antiemetic that increases the risk of QT prolongation 1.
- The ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death list several medications that can cause QT prolongation, but do not specifically mention metoclopramide 2. However, the more recent guideline from the British Thoracic Society 1 takes precedence in this case due to its recency and relevance to the topic of QT interval prolongation.
From the Research
QT Interval Prolongation and Reglan (Metoclopramide)
- Reglan (Metoclopramide) has been associated with QT interval prolongation, which can increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia 3, 4.
- The risk of QT prolongation is higher when metoclopramide is used in combination with other medications that can prolong the QT interval, such as ondansetron and fluoxetine 3.
- Electrolyte disturbances, such as hypokalemia and hypomagnesemia, can also contribute to QT prolongation and increase the risk of TdP when metoclopramide is used 3.
- The QT interval can be monitored and managed to reduce the risk of QT prolongation and TdP, especially in patients with risk factors such as female sex, age >65 years, and uncorrected electrolyte disturbances 5, 6.
- A list of specific drugs that prolong the QT interval, including metoclopramide, can be found at www.qtdrugs.org 6.