Abstract
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.
Original language | English (US) |
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Pages (from-to) | 296-302 |
Number of pages | 7 |
Journal | Psychopharmacology |
Volume | 178 |
Issue number | 2-3 |
DOIs | |
State | Published - Mar 2005 |
Keywords
- Attention
- Cognition
- Cognitive performance
- Concentration
- Dopamine
- Humans
- Isradipine
- Methamphetamine
- Perceptual-motor function
ASJC Scopus subject areas
- Pharmacology