ic 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).
Amoxicillin; Clarithromycin; Lansoprazole: Clarithromycin is associated with an established risk for QT prolongation and torsades de pointes (TdP). Clarithromycin should be used cautiously with other agents known to cause QT prolongation. Agents with potential to prolong the QT interval include: dolasetron.
Amoxicillin; Clarithromycin; Omeprazole: Clarithromycin is associated with an established risk for QT prolongation and torsades de pointes (TdP). Clarithromycin should be used cautiously with other agents known to cause QT prolongation. Agents with potential to prolong the QT interval include: dolasetron.
Anagrelide: Torsades de pointes (TdP) and ventricular tachycardia have been reported during post-marketing use of anagrelide. A cardiovascular examination, including an ECG, should be obtained in all patients prior to initiating anagrelide therapy. Monitor patients during anagrelide therapy for cardiovascular effects and eva luate as necessary. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with anagrelide include dolasetron.
Anthracyclines: Dolasetron has been associated with a dose-dependant prolongation in the QT, PR, and QRS intervals on an electrocardiogram. Dolasetron injection is contraindicated for use for the prevention of chemotherapy-induced nausea and vomiting because the risk of QT prolongation is higher with the doses used 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. Dolasetron should be used cautiously with anthracyclines such as daunorubicin or doxorubicin due to the potential risks for anthracycline cardiac toxicity. Acute cardiotoxicity can occur during administration of daunorubicin or doxorubicin; cumulative, dose-dependent cardiomyopathy may also occur. Acute ECG changes during anthracycline therapy are usually transient and include ST-T wave changes, QT prolongation, and changes in QRS voltage. Sinus tachycardia is the most common arrhythmia, but other arrhythmias such as supraventricular tachycardia (SVT), ventricular tachycardia, heart block, and premature ventricular contractions (PVCs) have been reported during anthracycline therapy.
Apomorphine: The concurrent use of apomorphine and serotonin-receptor antagonists is contraindicated due to the possibility of an excessive lowering of blood pressure and unconsciousness. Additionally, dolasetron and ondansetron may cause additive QT prolongation with apomorphine.
Aprepitant, Fosaprepitant: Aprepitant, fosaprepitant is indicated for the prophylaxis of chemotherapy-induced nausea/vomiting in combination with a 5HT3 antagonist, one of which is dolasetron. Dolasetron is a CYP3A4 substrate. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer; substitution of fosaprepitant 115 mg IV on day 1 of the 3-day regimen may lessen the inhibitory effects of CYP3A4. The AUC of another CYP3A4 substrate, midazolam, was increased for several days after aprepitant dosing when the two drugs were coadministe |
