Do you have to wean off lexapro to start taking Cymbalta?

Cymbalta is an SNRI, meaning it increases both serotonin and norepinephrine, while lexapro is an SSRI, meaning it increases only serotonin. These drugs that inhibit the reuptake of neurotransmitters MUST BE SWITCHED GRADUALLY. If switching from cymbalta to lexapro, the physician should induce a "step-down" therapy on the cymbalta while inducing a "step-up" therapy on lexapro. This ensures a level amount of drug in the blood, and minimizes the chance of recurrence and adverse effects.