Digitalis digitalis. As a result of increased contractility, stroke volume is increased. Ultimately, digitalis increases cardiac output (Cardiac Output=Stroke Volume x Heart Rate). This is the mechanism that makes this drug a popular treatment for congestive heart failure, which is characterized by low cardiac output. Digitalis also has a vagal effect on the parasympathetic nervous system, and as such is used in re-entrant cardiac arrhythmias and to slow the ventricular rate during atrial fibrillation. The dependence on the vagal effect means digitalis is not effective when a patient has a high sympathetic nervous system drive, which is the case with acutely
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