Treatment Failure and Use of Long-acting Preparations

Treatment Failure

If a child fails to show improvement as the stimulant dose is be-ing increased, how far should the dose be increased before turn-ing to another medication? The physician is left with the dose range suggested in the PDR and to his or her own standards re-garding what constitutes improvement and where to draw the line between a response and failure.

Do true nonresponders exist? Recent studies indicate that many apparent nonresponders to stimulants may simply have been treated with too low a dose. The treating physician is well advised to seek expert consultation with a child and adolescent psychopharmacologist before venturing beyond a total dose of 60 mg/day of MPH and 40 mg/day of DEX.

Use of Long-acting Preparations

There are three reasons for the implementation of longer-acting stimulant preparations. First, children who take medications in school are subject to peer ridicule when they leave activities to go to the nurse. Secondly, some school officials refuse to allow school personnel involvement in the administration of medica-tion. Thirdly, the time–action course of standard stimulant medi-cations allows only a brief 1- to 3-hour window of effect, so some medicated children may experience trough periods of little or no drug action during important parts of the school day.

Sustained-release preparations have been marketed for DEX and MPH. MPH’s sustained-release preparation (MPH-SR), which became available in 1984, is manufactured in brand (Rita-lin-SR) and generic (MD Pharmaceuticals) versions but only in a single strength of 20 mg (MPH-SR20). DEX spansules are availa-ble in 5-, 10- and 15 mg strengths in the brand version (Dexedrine Spansules). The sustained-release preparations make it possible to give the psychostimulant once in the morning and avoid ad-ministration during the school day. Ritalin-SR uses a wax-matrix vehicle for slow release, whereas the DEX “spansule” is a capsule containing small medication particles.