Drug Profile: Cymbalta

Side Effects, Warnings, Interactions

Older man taking pills on bed. David Burton/ GettyImages

Cymbalta (duloxetine hydrochloride) is a serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressant. It is taken by mouth as a pill or capsule.

Indications and Usage

Cymbalta is used for the treatment of major depressive disorder. The effectiveness of Cymbalta for longer-term use, or more than nine weeks, has not been systematically evaluated in clinical trials. It is also used for the management of diabetic peripheral neuropathic pain, fibromyalgia, chronic muscle and bone pain and generalized anxiety disorder.


Cymbalta should not be used by anyone who has shown a sensitivity to duloxetine or any of Cymbalta's inactive ingredients. It should also not be used at the same time as a monoamine oxidase inhibitor (MAOI) antidepressant. In clinical trials, Cymbalta was associated with increased mydriasis, which is dilation of the pupil of the eye, in patients with uncontrolled narrow-angle glaucoma and should not be used by patients with this condition.


There have been some reports of liver failure in patients using Cymbalta. It has also been associated with an increase in blood pressure, so blood pressure should be monitored throughout treatment. Cymbalta should be used with caution in patients with a history of mania or seizures. It should not be used in those with uncontrolled narrow-angle glaucoma. It should be discontinued gradually to avoid discontinuation symptoms. Experience with Cymbalta in patients with other illnesses is limited.


Patients should be observed closely for worsening depression and suicidality, especially at the beginning of treatment or when dose changes are made. Patients should also be monitored for symptoms such as anxiety, agitation, restlessness, panic attacks, insomnia, irritability, hostility, impulsivity, hypomania and mania. If such symptoms are severe, occur suddenly or were not symptoms that were present before treatment began, consideration should be given to changing the patient to a different medication.

Drug Interactions

Information about drug interactions is too lengthy to summarize here. Please visit the FDA's website or speak with your doctor or pharmacist for more complete information.

Carcinogenesis, Mutagenesis, Impairment of Fertility

In female mice receiving an equivalent of 11 times the maximum recommended human dose (MRHD), there was an increase in hepatocellular adenomas and carcinomas. The no-effect dose was 4 times the MRHD. Tumor incidence was not increased in male mice at doses up to 8 times the MRHD. It was not mutagenic in studies performed nor did it affect fertility.

Pregnancy and Lactation

Cymbalta is a Class C drug. There are no adequate and well-controlled studies in pregnant women, so duloxetine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Side Effects of Cymbalta

The most common adverse events, reported by greater than 5%, were nausea, dry mouth, constipation, decreased appetite, fatigue, sleepiness, and increased sweating. Adverse events occurring in at least 2% of patients included diarrhea, vomiting, weight loss, dizziness, tremor, hot flushes, blurred vision, insomnia, anxiety and sexual side-effects.

Drug Abuse and Dependence

Duloxetine is not a controlled substance. In animal studies, it did not demonstrate barbiturate-like abuse potential. In drug dependence studies, it did not demonstrate dependence-producing potential in rats. While Cymbalta has not been systematically studied in humans for its potential for abuse, there were no indications of drug-seeking behavior in the clinical trials.

Dosage and Administration

Cymbalta should be administered at a total daily dose of 40-60 mg/day. Generally, it will be split into two doses taken at different times of the day. It is not necessary to take it with food. There is no evidence that doses greater than 60 mg/day confer any additional benefits.

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