Digitalis purpurea pharmacological forms, extracts of this plant did not frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more. The main toxins in "Digitalis" spp. are the two chemically similar cardiac glycosides: digitoxin and digoxin. Like other cardiac glycosides, these toxins exert their effects by inhibiting the ATPase activity of a complex of transmembrane proteins that form the sodium potassium ATPase pump, (Na/K-ATPase). Inhibition of the Na/K-ATPase in turn causes a rise not only in intracellular Na, but also in calcium, which in turn results in increased force of myocardial muscle contractions.
Recreational drug use part of the milieu of drug taking. The reasons for drug use appear to have as much to do with needs for friendship, pleasure and status as they do with unhappiness or poverty. Becoming a drug taker, to many people, is a positive affirmation rather than a negative experience.” Anthropological research has suggested that humans "may have evolved to counter-exploit plant neurotoxins". The ability to use botanical chemicals to serve the function of endogenous neurotransmitters may have improved survival rates, conferring an evolutionary advantage. A typically restrictive prehistoric diet may have emphasised the apparent benefit of consuming psychoactive drugs, which