Methylphenidate increases the motor effects of L-dopa in Parkinson's disease: A pilot study

Richard Camicioli, Eric Lea, John G. Nutt, Gary Sexton, Barry S. Oken

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


We determined whether methylphenidate, a dopamine transporter blocker, modifies motor, cognitive, or affective responses to L-Dopa in Parkinson's disease (PD). Five patients who reported benefit from L-Dopa/carbidopa and motor fluctuations were admitted and withdrawn from their usual antiparkinsonian medications. On 3 consecutive days in a randomized double-blinded fashion, they took 0.2 mg/kg oral methylphenidate or placebo followed 30 minutes later by a 1-hour intravenous L-Dopa (2 mg/kg per h) or placebo infusion. Vital signs, tapping, walking, dyskinesias, mood, anxiety, concentration, and arousal were monitored every 30 minutes. Cognitive testing was performed before and following the infusion. Methylphenidate combined with L-Dopa led to greater peak right-hand tapping speed than either alone. Dyskinesia severity increased most when methylphenidate and L-Dopa were co-administered. There were no differences between conditions on the Stroop test, digit ordering, simple reaction time, or covert orienting of attention validity effect. Methylphenidate alone led to improvement in choice reaction time. Change in self-assessed analogue ratings of mood, anxiety, arousal, or concentration did not differ between conditions. Methylphenidate increased the motor effects of L-Dopa with minimal effects on cognitive or affective functions, suggesting a physiologic role for the dopamine transporter in patients with PD with motor fluctuations.

Original languageEnglish (US)
Pages (from-to)208-213
Number of pages6
JournalClinical neuropharmacology
Issue number4
StatePublished - 2001


  • Dopamine transporter
  • L-Dopa
  • Methylphendidate
  • Parkinson's disease
  • Pharmacodynamics

ASJC Scopus subject areas

  • Pharmacology
  • Clinical Neurology
  • Pharmacology (medical)


Dive into the research topics of 'Methylphenidate increases the motor effects of L-dopa in Parkinson's disease: A pilot study'. Together they form a unique fingerprint.

Cite this