qt prolongation
3 interactions related to qt prolongation
grapefruit + methadone
Grapefruit inhibits intestinal CYP3A4, an enzyme that partly clears methadone, which can raise methadone blood levels. The effect is usually modest in stable patients but can become clinically significant with sustained heavy intake.
amiodarone + grapefruit
Grapefruit and grapefruit juice inhibit intestinal CYP3A4, the enzyme that metabolizes oral amiodarone. This raises amiodarone blood levels and largely shuts down 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 coordination. The FDA label states trazodone may enhance the response to alcohol, and combining the two raises the risk of falls and accidents. Rarely, trazodone is associated with QT prolongation, orthostatic syncope, and priapism.