Table 4

 Interactions of psychotropic and cardiac medications: interactions involving tricyclic antidepressants and serotonergic antidepressants

MedicationEffect on cardiac agent
Interactions involving tricyclic antidepressants
    Type Ia antiarrhythmicsPotentiate delay in cardiac conduction; heart block
    Antihypertensives: guanethidine, clonidine, reserpineAntagonise antihypertensive effect; potentiate orthostatic hypotension
    Sublingual nitratesOral absorption hindered by dry mouth
    α-Adrenergic blocking agentsPotentiate antihypertensive effect
Interactions involving serotonergic antidepressants
    Lipophilic β-blockersIncrease blood levels due to decreased hepatic degradation
    Calcium channel blockers
    Type Ic antiarrhythmics
    Angiotensin converting enzyme inhibitors
    DigitoxinIncrease bioavailability due to displacement from protein-binding sites