Effects of isradipine on methamphetamine-induced changes in attentional and perceptual-motor skills of cognition

Psychopharmacology (Berl). 2005 Mar;178(2-3):296-302. doi: 10.1007/s00213-004-1998-0. Epub 2004 Sep 25.


Rationale: While the effects of d-amphetamine in increasing performance have been established, there is a paucity of information on the effects of methamphetamine on cognition in drug-naive subjects, and no published information on the effects of intravenous methamphetamine administration in dependent individuals. The dihydropyridine-class calcium channel antagonist, isradipine, has been posited as a putative treatment to prevent methamphetamine-associated hypertensive crisis and its sequelae. Yet, isradipine's effects on cognitive performance in methamphetamine-dependent individuals are not known.

Objective: Since individuals whose dependence on methamphetamine is attributable to the need to enhance performance may be loath to take a cognition-impairing medication, even for the treatment of life-threatening hypertensive crisis, it would be important to determine isradipine's effects on performance.

Methods: We therefore examined in a blinded, placebo-controlled, crossover design the cognitive effects of low and high doses of intravenous methamphetamine (15 mg and 30 mg, respectively) in both the presence and absence of isradipine.

Results: Intravenous d-methamphetamine produced dose-dependent increases in attention, concentration, and psychomotor performance. Isradipine, both with and without methamphetamine, had a modest effect to decrease attention.

Conclusion: Our results do not support the further testing of isradipine as a medication for improving the cognitive impairments that have been associated with chronic methamphetamine use.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Amphetamine-Related Disorders / psychology
  • Amphetamine-Related Disorders / rehabilitation*
  • Antihypertensive Agents / administration & dosage*
  • Antihypertensive Agents / adverse effects
  • Area Under Curve
  • Attention / drug effects*
  • Calcium Channel Blockers / administration & dosage*
  • Calcium Channel Blockers / adverse effects
  • Cross-Over Studies
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Interactions
  • Drug Therapy, Combination
  • Female
  • Humans
  • Isradipine / administration & dosage*
  • Isradipine / adverse effects
  • Male
  • Methamphetamine* / toxicity
  • Psychomotor Performance / drug effects*
  • Reaction Time / drug effects
  • Substance Abuse, Intravenous / psychology
  • Substance Abuse, Intravenous / rehabilitation*
  • Treatment Outcome


  • Antihypertensive Agents
  • Calcium Channel Blockers
  • Methamphetamine
  • Isradipine