Can i use voltaren gel for my neck when taking ritalin (methylphenidate) and faverin ( luvox) ? is it harmful ?

You can, but : You should be closely monitored by your doctor. There are some interactions for the named medications. However, Luvox (fluvoxamine) + voltaren combo increases toxicity by added drug effects. Luvox (fluvoxamine) +ritalin combo increases effects of Luvox (fluvoxamine) oral by slowing drug metabolism. Call your doctor immediately if you notice worsening depression/other psychiatric conditions, unusual behavior and mood changes.

No problem: There should be no problem with this combination.