From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
You should not take Cymbalta (duloxetine) with Plavix (clopidogrel) without consulting your healthcare provider due to the potential increased risk of bleeding. While they can be prescribed together in certain situations, there are some concerns to be aware of. Cymbalta may slightly increase the risk of bleeding, and since Plavix is a blood thinner that also increases bleeding risk, the combination could potentially enhance this side effect 1. Additionally, Cymbalta may reduce the effectiveness of Plavix in some people because both medications are processed by similar liver enzymes. Your doctor needs to evaluate your specific medical conditions, bleeding risk factors, and the necessity of both medications before making a recommendation. They might need to monitor you more closely for signs of bleeding or adjust dosages if both medications are deemed necessary for your treatment. Some key factors that increase the risk of bleeding with clopidogrel therapy include concomitant aspirin use and long duration of clopidogrel therapy 1. Never stop taking either medication without medical guidance, as this could lead to serious health consequences. It's also important to note that reduced renal function is a risk factor for clinical ineffectiveness of clopidogrel 1. In general, the risk of bleeding with dual antiplatelet therapy, including clopidogrel, is well-documented and should be carefully considered when prescribing these medications together with other drugs that may increase bleeding risk, such as Cymbalta 2, 3.