Err, no. Methamphetamine is significantly different from methylphenidate. Methylphenidate (Concerta, Ritalin, etc) is more closely related to amphetamine, but

Err, no. Methamphetamine is significantly different from methylphenidate. Methylphenidate (Concerta, Ritalin, etc) is more closely related to amphetamine, but still not a derivative. It's like saying that thebaine is a derivative of codeine due to them being similar in structure.