Sustained-release methylphenidate: new preparations. New pharmaceutical forms: a slight advantage for a small number...

(1) When non-drug measures don't work in severe attention-deficit/hyperactivity disorder, methylphenidate, an amphetamine, attenuates symptoms in about 75% of children, at least in the short term. (2) Two forms of sustained-release methylphenidate--tablets (Concerta LP) and microgranule-filled capsules (Ritaline LP)--are marketed in France. (3) In two cross-over trials (one week per treatment) and in a parallel-group trial lasting one month, sustained-release methylphenidate tablets (18 mg to 54 mg/day in a single dose) were no more or less effective than short-acting methylphenidate (5 mg to 15 mg three times a day), but the sustained-release formulation was significantly more effective than placebo. The rating scale used in these trials was not sensitive enough to show whether the two forms had the same duration of action. A one-year non comparative trial in 435 children suggested that initial efficacy persisted in at least half the children treated with sustained-release tablets. (4) The only clinical trial of sustained-release methylphenidate capsules--a randomised double-blind placebo controlled trial lasting two weeks--showed that sustained-release capsules were more effective than placebo. (5) All these short-term trials confirmed the known amphetamine-like adverse effects of methylphenidate. The sustained-release tablets are large and rigid. They have the potential to cause gastrointestinal obstruction. (6) The sustained-release tablets can be difficult to swallow, and must not be cut, crushed, or chewed. The capsules can be opened so the microgranules inside them can be mixed with food. (7) In practice, it is best to start with short-acting methylphenidate, which is better evaluated than sustained-release formulations. If it's effective, and if treatment needs to be simplified, the child can be switched to a sustained-release form later; capsules are less risky than tablets, and are also more convenient.