ABSTRACT
Ethanol, caffeine, and nicotine share the distinction of being commonly used legal drugs that have profound state-altering characteristics. They are drugs that are recognized for their addictive liability, although caffeine is less so recognized than ethanol and nicotine. Ethanol is a highly water- and lipid-soluble molecule that follows a single compartment pharmacokinetic model. The primary effect of ethanol on alertness and waking function is one of sedation and disturbed performance. Nicotine is a tertiary amine with central nervous system stimulatory effects. It is present in various tobacco products. The study of the effects of nicotine on the sleep of healthy non-smokers was facilitated with the development of nicotine delivery systems for use in clinical smoking cessation programs. The state-altering actions of ethanol, caffeine, and nicotine have been well documented and are consistent with the known pharmacokinetics of the drugs. Ethanol intially enhances sleep and later in the night disrupts sleep, while caffeine and nicotine consistently disrupt sleep.
