Pharmacokinetics and pharmacodynamics of scopolamine after subcutaneous administration

J Clin Pharmacol. 1998 Aug;38(8):720-6. doi: 10.1002/j.1552-4604.1998.tb04812.x.

Abstract

The effects of subcutaneously administered scopolamine on quantitative electroencephalogram (qEEG) and cognitive performance were evaluated and correlated with pharmacokinetic parameters in a randomized, double-blind placebo-controlled crossover study of 10 healthy male volunteers. Changes in qEEG and cognition were determined for 8 hours after drug administration. Scopolamine produced dose- and time-dependent impairments of attention and memory and a time-dependent increase in delta power (1.25-4.50 Hz) and a decrease in fast alpha power (9.75-12.50 Hz) on qEEG compared with placebo. Maximum serum concentrations of scopolamine occurred 10 to 30 minutes after drug administration. Mean peak serum concentrations (free base) were 3.27, 8.99, and 18.81 ng/mL after administration of 0.4, 0.6 mg, and 0.8 mg scopolamine, respectively. Elimination half-life was approximately 220 minutes. The findings indicate temporary changes in qEEG and psychometric tests, and support the possible use of such a testing model for impaired cognitive functions such as age-related memory disturbances.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cross-Over Studies
  • Double-Blind Method
  • Electroencephalography / drug effects
  • Humans
  • Injections, Subcutaneous
  • Male
  • Mental Recall / drug effects
  • Muscarinic Antagonists / administration & dosage
  • Muscarinic Antagonists / adverse effects
  • Muscarinic Antagonists / pharmacokinetics*
  • Psychometrics
  • Psychomotor Performance / drug effects
  • Reaction Time / drug effects
  • Scopolamine / administration & dosage
  • Scopolamine / adverse effects
  • Scopolamine / pharmacokinetics*

Substances

  • Muscarinic Antagonists
  • Scopolamine