Interaction between cymbalta (duloxetine) and ritalin, how is serious?

Not serious. There are no known significant interactions between those two drugs.
Cymbalta (duloxetine) and Ritalin. I am happy to report to you that there are no drug drug interactions between Cymbalta (duloxetine) and ritalin. I checked at www.Drugs.Com as well as epocrates. No interactions could be found.