What Are the Risks of Taking Cymbalta & Zoloft Together?

Medication is complicated business. Doctors go to school for years to learn how best to treat illnesses, but that doesn't mean they always remember to inform patients of all the risks or side-effects related to how prescription drugs interact. That is especially true if patients receive prescriptions from more than one doctor. Drugs used to treat depression or mood disorders affect patients differently, but it's important to stay informed about known interactions when taking Cymbalta and Zoloft at the same time,

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Cymbalta and Zoloft are both brand name prescription medications used primarily to treat depression. Both drugs are known as antidepressants and serve as potent dual reuptake inhibitors of serotonin and norepinephrine. Zoloft, however, is often in a class of drugs known as SSRIs or selective serotonin reuptake inhibitors. Current clinical pharmacology has, to date, been unable to determine the causal impetus for how Cymbalta improves or stabilizes a patient's mood nor pinpoint how the duloxetine contained in Cymbalta affects humans. Despite this, the FDA has approved both drugs for the treatment of severe depression.

Interaction Effects

Cymbalta contains duloxetine and Zoloft contains sertraline, the combination of these two drugs creates what pharmacists describe as a "major drug-drug interaction." Used together, the drugs present the potential for a patient to develop "serotonin syndrome." Although rare, this is a serious condition that can result in death caused by hyperstimulation of the patient's brainstem.


Doctors usually avoid prescribing more than one serotonergic drug to a patient because of the risks involved with such cocktails. When patients are prescribed more than one such drug, doctors weigh the benefits of the treatment against the risks involved. If a patient receives both Cymbalta and Zoloft, the patient should be monitored closely for signs of serotonin syndrome.


It is important for patients coming off a serotonegic medication to provide their doctor with this information because some of these drugs have a prolonged half-life. A life-threatening risk might occur if a doctor prescribes a second serotonegic drug without knowing a prior serotonegic drug had not yet been eliminated from the patient's system. With close monitoring, signs of serotonin syndrome might be dealt with quickly by the attending physician and the drug combination.


While Zoloft and Cymbalta are two classes of drugs often used to treat depression, there are several other drugs available that can present less interaction risks. It is important to talk with your physician about side-effects you experience when starting a particular medication, adjusting a dose or combining with another drug. Tolerance levels differ among patients as do the severity of side-effects patients experience when taking medication. Psychiatrists acknowledge that the treatment of mental illness with medication is as much an art as it is a science.