Better efficacy for the osmotic release oral system methylphenidate among poor adherents to immediate-release methylphenidate in the three ADHD subtypes.
OBJECTIVE
To determine factors for switching to osmotic release oral system methylphenidate (OROS-MPH) among poor adherents to immediate-release methylphenidate (IR-MPH); and to compare the efficacy of OROS-MPH on the three attention-deficit/hyperactivity disorder (ADHD) subtypes in a multi-site prospective observational study in Taiwan.


METHODS
The sample included 240 children with ADHD, aged 6-16 years, who were poor adherents to IR-MPH, 137 of whom were switched to OROS-MPH. The child psychiatrists diagnosed the Diagnostic Statistical Manual of Mental Disorders (4th edition) ADHD subtypes and assessed the medical history, adherence, side-effects, global ADHD severity, and family/school effectiveness. Parents reported their child's behavioral symptoms.


RESULTS
The determinants for an OROS-MPH switch were higher dosage, shorter treatment and thrice-daily administration of IR-MPH, and more severe inattention symptoms. Hyperactivity and oppositional symptoms were greater in the ADHD combined and hyperactive-impulsive subtypes than the inattentive subtype. Switching to OROS-MPH significantly improved behavioral symptoms and family/school measures, and this was most evident in the ADHD-combined group, followed by the ADHD-inattentive group. Inattention influenced not only academic performance, but also overall classroom behaviors and the parent-child relationship, with the latter two also influenced by oppositional symptoms.


CONCLUSIONS
This study suggests better efficacy for the OROS-MPH among poor adherents to IR-MPH; however, its effectiveness varied across the three ADHD subtypes (ClinicalTrials.gov number NCT00460720).
Chou
Wen-Jiun
WJ
Department of Child Psychiatry, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Chou
Miao-Chun
MC
Tzang
Ruu-Fen
RF
Hsu
Ya-Chen
YC
Gau
Susan Shur-Fen
SS
Chen
Shin-Jaw
SJ
Wu
Yu-Yu
YY
Huang
Ya-Fen
YF
Liang
Hsin-Yi
HY
Cheng
Helen
H