qt prolongation
3 interactions related to qt prolongation
grapefruit + methadone
Methadone is partially metabolized by CYP3A4 (and CYP2B6). Grapefruit juice inhibits intestinal CYP3A4 and can raise methadone plasma concentrations, with case reports of opioid toxicity after sustained grapefruit juice intake. Higher methadone levels also increase the risk of QT prolongation and torsades de pointes.
amiodarone + grapefruit
Grapefruit juice inhibits intestinal CYP3A4, raising oral amiodarone AUC by approximately 50% and peak levels by 84% while abolishing production of its active metabolite N-desethylamiodarone. The FDA-approved Pacerone label explicitly states grapefruit juice should not be consumed during oral amiodarone treatment.
alcohol + trazodone
Trazodone and alcohol both depress the central nervous system, producing additive sedation, dizziness, orthostatic hypotension, and impaired psychomotor performance. The combination also increases risk of falls, accidents, and rarely, dangerous arrhythmias related to QT prolongation.