From the Guidelines
Caution is advised when giving Seroquel (quetiapine) to a patient taking amiodarone due to potential drug interactions that can prolong the QT interval, increasing the risk of torsades de pointes and other dangerous heart rhythm disturbances. Both medications can affect cardiac repolarization, with the combined impact potentially greater than either drug alone 1. If co-administration is necessary, it should be done with careful cardiac monitoring, including baseline and follow-up ECGs to assess QT interval changes.
- Lower starting doses of Seroquel may be appropriate, with gradual titration based on clinical response and ECG findings.
- Patients should be monitored for symptoms such as dizziness, palpitations, or syncope, which could indicate cardiac rhythm problems.
- The risk is higher in patients with other risk factors for QT prolongation, such as electrolyte abnormalities, heart disease, or use of additional QT-prolonging medications. This interaction is a concern because amiodarone is a potent QT-prolonging drug, and the simultaneous administration of other drugs that delay repolarization, such as quetiapine, can increase the risk of adverse reactions 1.
- In some cases, alternative medications with less QT-prolonging potential might be considered if appropriate for the patient's condition.
- Before prescribing a psychotropic drug like Seroquel, physicians should carefully assess its risks and benefits to avoid these adverse reactions, particularly when additional risk factors are present 1.
From the Research
Drug Interactions and QT Interval Prolongation
- Amiodarone is known to prolong the QT interval, which can increase the risk of torsades de pointes and other arrhythmias 2.
- Quetiapine, also known as Seroquel, is an antipsychotic medication that can also prolong the QT interval, particularly when used in combination with other medications that affect the QT interval 3, 4.
- The risk of QT interval prolongation and torsades de pointes is increased when multiple medications that affect the QT interval are used concomitantly, such as amiodarone and quetiapine 2, 3.
Management of Patients Taking Amiodarone and Quetiapine
- Clinicians should be aware of the potential risks of QT interval prolongation and torsades de pointes when prescribing quetiapine to patients taking amiodarone 5.
- Electrocardiogram (ECG) monitoring may be useful in patients taking quetiapine and amiodarone, particularly if there are other risk factors for QT interval prolongation, such as hypokalemia or hypomagnesemia 3, 5.
- The decision to use quetiapine in patients taking amiodarone should be made on a case-by-case basis, taking into account the potential benefits and risks of the medication 5.
Monitoring and Follow-up
- Patients taking quetiapine and amiodarone should be monitored regularly for signs of QT interval prolongation and torsades de pointes, including ECG monitoring and clinical evaluation 3, 5.
- The incidence of arrhythmias in patients taking antipsychotic medications, including quetiapine, is generally low, but can be increased in patients with underlying cardiac risk factors or those taking multiple medications that affect the QT interval 6.