title: Comparison of acute behavioral effects of sustained-release and immediate-release methylphenidate.
abstract: The rate of onset of a drug's effect is an important determinant of its abuse potential. This experiment examined the acute behavioral effects of orally administered sustained-release methylphenidate (SR; 20-40 mg), immediate-release methylphenidate (IR; 20-40 mg), and placebo in 10 healthy volunteers. Drug effects were assessed before drug administration and periodically afterwards for 6 hr using drug-effect questionnaires and performance measures that are sensitive to the acute effects of stimulants. The IR formulation produced stimulant-like drug effects (e.g., increased ratings of "good effects") that generally varied as a function of dose and time. The SR formulation produced only transient effects on these measures. These findings are consistent with previous research on the influence of rate of onset using other drugs and suggest that the abuse potential of IR methylphenidate may be greater than that of SR methylphenidate.
authors.affiliation: Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson 39216, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Kollins
authors.forename: C R
authors.initials: CR
authors.lastname: Rush
authors.forename: P J
authors.initials: PJ
authors.lastname: Pazzaglia
authors.forename: J A
authors.initials: JA
authors.lastname: Ali
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects; D000818:Animals; D001519:Behavior / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000494:pharmacology*; D003692:Delayed-Action Preparations; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000494:pharmacology*; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000187:drug effects; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants; D003692:Delayed-Action Preparations; D008774:Methylphenidate