Do ritalin (methylphenidate) and klonopin cancel each other?

No: While Ritalin (methylphenidate) is a stimulant and Klonopin is a sedative, they both work in very different ways on your body. With that said, using both medications at the same time should only be done with the close supervision and guidance of a physician with a high level of psychiatric knowledge. Such as a psychietrist or a primary care physician with a large background in mental health.

Likely: Ritalin (methylphenidate) is a stimulant in other words an upper. Klonopin is a valium derivitive, produces sedation and calming, in other words a downer. They will likely cancel each other out.