eported in patients treated with fluoxetine, the manufacturer recommends caution when using fluoxetine with other drugs that prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP include dolasetron.
Fluoxetine; Olanzapine: Due to a possible risk for QT prolongation and torsade de pointes (TdP), dolasetron and olanzapine 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. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances. Therefore, caution is advised when administering olanzapine with drugs having an established causal association with QT prolongation and torsade de pointes (TdP). Taking these drugs together may increases the risk for serotonin syndrome. 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. In addition, because QT prolongation and torsade de pointes (TdP) have been reported in patients treated with fluoxetine, the manufacturer recommends caution when using fluoxetine with other drugs that prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP include dolasetron.
Fluphenazine: Due to a possible risk for QT prolongation and torsade de pointes (TdP), dolasetron and fluphenazine 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. Fluphenazine, a phenothiazine, is associated with a possible risk for QT prolongation.
Fluvoxamine: Because of the potential risk and severity of serotonin syndrome, use caution when administering dolasetron with other drugs that have serotonergic properties such as fluvoxamine. 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.
Foscarnet: When possible, avoid concurrent use of foscarnet with other drugs known to prolong the QT interval, such as dolasetron. Foscarnet has been associated with postmarketing reports of both QT prolongation and torsade de pointes |
