oniazid, INH; Rifampin: Blood concentrations of hydrodolasetron, the active metabolite of dolasetron, may be decreased when dolasetron is administered concomitantly with rifampin, a potent inducer of cytochrome P450.
Itraconazole: Itraconazole is a potent inhibitor of CYP3A4. Coadministration of itraconazole with drugs that are CYP3A4 substrates that also prolong the QT interval, such as dolasetron, may result in an elevated plasma concentrations of that substrate and an increased risk for adverse events, including QT prolongation. In addition, itraconazole has been associated with QT prolongation. The manufacturer of itraconazole states that concomitant use of drugs that are known to prolong that QT interval and are metabolized by CYP3A4 may be contraindicated with itraconazole; however, the manufacturer of posaconazole, another systemic azole with potent inhibitory activity against CYP3A4, contraindicates the use of posaconazole with drugs that prolong the QT interval and are metabolized by CYP3A4. Because itraconazole also is a potent inhibitor of CYP3A4, it would be prudent to follow the same recommendations. It also is prudent to not use dolasetron for up to 2 weeks after discontinuation of itraconazole treatment unless benefits of treatment outweigh the potentially increased risk of side effects.
Ivacaftor: Use caution when administering ivacaftor and dolasetron concurrently. Ivacaftor is an inhibitor of CYP3A and dolasetron is partially metabolized by CYP3A. Co-administration of ivacaftor with CYP3A substrates, such as dolasetron, can theoretically increase dolasetron exposure leading to increased or prolonged therapeutic effects and adverse events; however, the clinical impact of this has not yet been determined.
Ketoconazole: Coadministration of ketoconazole with drugs that are CYP3A4 substrates that also prolong the QT interval may result in an elevated plasma concentrations of that substrate and an increased risk for adverse events, including QT prolongation. Ketoconazole in itself can prolong the QT interval. In addition, ketoconazole is a potent inhibitor of CYP3A4. The manufacturer of ketoconazole states that concomitant use of drugs that are known to prolong that QT interval and are metabolized by CYP3A4 may be contraindicated with ketoconazole; however, the manufacturer of posaconazole, another systemic azole with potent inhibitory activity against CYP3A4, contraindicates the use of posaconazole with drugs that prolong the QT interval and are metabolized by CYP3A4. Because ketoconazole also is a potent inhibitor of CYP3A4, it would be prudent to follow the same recommendations. Drugs that prolong QT and are substrates for CYP3A4 include dolasetron.
Lacosamide: QT prolongation occurred in some patients receiving lacosamide during clinical trials. Therefore, caution is advised when administering lacosamide with drugs with a possible risk for QT prolongation and torsade de pointes (TdP) including dolasetron.
Lapatinib: Due to a possible risk for QT prolongation and torsade de pointes (TdP), dolasetron and lapatinib 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. |
