We are offering ritalin. Sell offer details: ritalin - treating attention deficit disorder (add). It is also used to treat uncontrollable periods of daytime sleep (narcolepsy). It may also be used for other conditions as determined by your doctor. Ritalin is a central nervous system . Exactly how it works is not known. Ritalin is a central nervous system used most commonly in the treatment of attention-deficit disorders in children and for narcolepsy.