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Fenfluramine and methylphenidate in children with mental retardation and borderline IQ: clinical effects

M G Aman1, R A Kern, P Osborne

  • 1Nisonger Center UAP, Ohio State University, Columbus 43210-1296, USA.

American Journal of Mental Retardation : AJMR
|March 1, 1997
PubMed

Insights

Methylphenidate and fenfluramine show effectiveness for children with ADHD and intellectual disability. Fenfluramine demonstrated improvements in behavior and compliance, but potential cognitive costs and side effects warrant careful dosage titration.

Area of Science:

  • Child Psychology
  • Neurodevelopmental Disorders
  • Pharmacology

Background:

  • Attention-Deficit/Hyperactivity Disorder (ADHD) often co-occurs with intellectual disability.
  • Limited research exists on pharmacological interventions for ADHD in this specific population.
  • Previous studies suggest stimulant medications are effective for ADHD, but non-stimulant options warrant investigation.

Purpose of the Study:

  • To evaluate the efficacy and safety of methylphenidate and fenfluramine in children with ADHD and mental retardation or borderline IQ.
  • To compare the effects of different fenfluramine dosages against placebo and methylphenidate.
  • To assess behavioral and cognitive outcomes based on parent, teacher, and physician ratings.

Main Methods:

  • A double-blind, placebo-controlled, crossover study design was employed.
  • Participants received methylphenidate (0.4 mg/kg/day) and varying doses of fenfluramine (1.0, 1.5, 2.0 mg/kg/day).
  • Children's behavior and cognitive function were rated by parents, teachers, examiners, and physicians.

Main Results:

  • Fenfluramine showed significant improvements on parent and teacher subscales at optimal doses compared to placebo and methylphenidate.
  • Methylphenidate resulted in some teacher-rated improvements.
  • The highest fenfluramine dose increased behavioral compliance but decreased cognitive efficiency.
  • Common side effects like drowsiness, dizziness, and anorexia were associated with fenfluramine.

Conclusions:

  • Both methylphenidate and fenfluramine appear to be effective treatments for ADHD in children with intellectual disability.
  • Fenfluramine may offer benefits for behavior and compliance, but careful dose titration is recommended due to potential side effects and cognitive impact.
  • A gradual increase to 1.5 mg/kg/day of fenfluramine is suggested for most children, with consideration for possible neurotoxic effects.

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