he QT, PR, and QRS intervals on an electrocardiogram. Use of dolasetron injection for the prevention of chemotherapy-induced nausea and vomiting is contraindicated because the risk of QT prolongation is higher with the doses required for this indication; when the injection is used at lower doses (i.e., those approved for post-operative nausea and vomiting) or when the oral formulation is used, the risk of QT prolongation is lower and caution is advised. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Dronedarone: Concomitant use of dronedarone and dolasetron is contraindicated. Dronedarone is an inhibitor of CYP2D6 and CYP3A. Dolasetron is a substrate for CYP2D6 and CYP3A4. Coadministration of dronedarone and dolasetron may result in elevated plasma concentrations of dolasetron. In addition, dolasetron has been established to have a possible risk of QT prolongation and Torsade de Pointes (TdP). Dronedarone is associated with dose-related increases in the QTc interval. Dolasetron has also been associated with a dose-dependant prolongation in the PR interval on an electrocardiogram. Although there are no studies examining the effects of dronedarone in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation; concomitant use is contraindicated.
Droperidol: Due to a possible risk for QT prolongation and torsade de pointes (TdP), dolasetron and droperidol should be used together cautiously. Dolasetron has been associated with a dose-dependant prolongation in the QT, PR, and QRS intervals on an electrocardiogram. Use of dolasetron injection for the prevention of chemotherapy-induced nausea and vomiting is contraindicated because the risk of QT prolongation is higher with the doses required for this indication; when the injection is used at lower doses (i.e., those approved for post-operative nausea and vomiting) or when the oral formulation is used, the risk of QT prolongation is lower and caution is advised. Droperidol should be administered with extreme caution to patients receiving other agents that may prolong the QT interval. Droperidol administration is associated with an established risk for QT prolongation and torsades de pointes (TdP). In December 2001, the FDA issued a black box warning regarding the use of droperidol and its association with QT prolongation and potential for cardiac arrhythmias based on post-marketing surveillance data. According to the revised 2001 labeling for droperidol, any drug known to have potential to prolong the QT interval should not be coadministered with droperidol.
Duloxetine: Because of the potential risk and severity of serotonin syndrome, use caution when administering dolasetron with other drugs that have serotonergic properties such as duloxetine. If serotonin syndrome is suspected, discontinue dolasetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
Efavirenz: Although data are limited, coadministration of efavirenz and dolasetron may increase the risk for QT prolongation and torsade de pointes (TdP). QT p |
