The absorption rate of zaleplon is rapid and the onset of therapeutic effects is typically breached within 5–15 minutes following ingestion. Zaleplon should be understood as an ultrashort-acting sedative-hypnotic drug for the treatment of insomnia. Zaleplon increases EEG power density in the δ-frequency band and a decrease in the energy of the θ-frequency band

Pharmacokinetics
Zaleplon is primarily metabolised by aldehyde oxidase, and its half-life can be affected by substances which inhibit or induce aldehyde oxidase. Taken orally, zaleplon reaches full concentration in about one hour. It is extensively metabolised into 5-oxozaleplon and 5-oxodesethylzaleplon (the latter via desethylzaleplon), with less than 1% of it excreted intact in urine. Chemistry
Pure zaleplon in its solid state is a white to off-white powder with very low solubility in water, as well as low solubility in ethanol and propylene glycol. It has a constant octanol-water partition coefficient of log P = 1.23 in the pH range between 1 and 7. It is classified as a pyrazolopyrimidine. Synthesis
The synthesis starts with the condensation of 3-acetylacetanilide (1) with N,N-dimethylformamide dimethyl acetal (DMFDMA) to give the eneamide (2). The anilide nitrogen is then alkylated by means of sodium hydride and ethyl iodide to give 3. The first step in the condensation with 3-amino-4-cyanopyrazole can be visualized as involving an addition-elimination reaction sequence on the eneamide function to give a transient intermediate such as 5. Cyclization then leads to formation of the fused pyrimidine ring to afford zaleplon (6).
Society and culture
Recreational use
Zaleplon has the potential to be a drug of recreational use, and has been found to have an addictive potential similar to benzodiazepine and benzodiazepine-like hypnotics. The mind- and judgment-altering effects of zaleplon are similar to those of many benzodiazepines, but the fast-acting nature and short half-life of the chemical mean high doses set on much more quickly and last for short periods of time (usually from 45 to 60 minutes). Some individuals use a different delivery method than prescribed, such as insufflation, to induce effects faster. A common effect of recreational zaleplon use is the occurrence of (typically short-lived) hallucinations. Fewer visual and auditory hallucinations/disruptions occur with the use of zaleplon than with other Z-drugs, like zolpidem. Anterograde amnesia can occur and can cause one to lose track of the amount of zaleplon already ingested, prompting the ingesting of more than originally planned. However, continuous ingestion is extremely unlikely precisely because of zaleplons quick onset of action.The combination of alcohol and zaleplon can result in fatal respiratory depression and asphyxiation from vomiting. Aviation use
The Federal Aviation Administration allows zaleplon with a 12-hour wait period and no more than twice a week, which makes it the sleep medication with the shortest allowed waiting period after use. The substances with the 2nd shortest period, which is of 24 hours, are zolpidem and ramelteon.