A post hoc analysis of d-threo-methylphenidate hydrochloride (focalin) versus d,l-threo-methylphenidate hydrochloride (ritalin).
OBJECTIVE
To evaluate clinical measures of the benefit/risk ratio in a post hoc analysis of a clinical trial of d-threo-methylphenidate hydrochloride (d-MPH) and d,l-threo-methylphenidate hydrochloride (d,l-MPH).


METHODS
Data from a phase III clinical trial was used to compare equimolar doses of d-MPH and d,l-MPH treatment for attention-deficit/hyperactivity disorder (ADHD) on clinician ratings of improvement/deterioration, teacher ratings of remission, and duration of action.


RESULTS
d-MPH was clinically and statistically significantly superior to d,l-MPH on clinician's dimensional ratings of global improvement, teacher ratings of remission of ADHD symptoms and parent 6:00 p.m. ADHD symptom ratings. No treatment differences were observed for symptom ratings at 3:00 p.m. and for 6:00 p.m. math test performance.


CONCLUSIONS
The results suggest that the two drugs may have distinct profiles on the measures analyzed. Because d-MPH may have be more than twice the potency of d,l-MPH, the differences reported here are only applicable to the doses of the study drugs involved in the clinical trial. The results are limited by the exploratory nature of our analysis, small samples, and multiple analyses. The findings are suggestive that further study is warranted to look at these differences prospectively but cannot be used to draw clinical conclusions at this time.
Weiss
Margaret
M
Division of Child Psychiatry, University of British Columbia, Vancouver, Canada. mweiss@cw.bc.ca
Wasdell
Michael
M
Patin
John
J
D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D017326:Clinical Trials, Phase III as Topic; D064699:Dexmethylphenidate Hydrochloride; D006801:Humans; D008774:Methylphenidate / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012189:Retrospective Studies; D013237:Stereoisomerism; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants; D064699:Dexmethylphenidate Hydrochloride; D008774:Methylphenidate