Atropine

Atropine is a naturally occurring tropane alkaloid that can be extracted from many plants of the Solanaceae family, such as deadly nightshade (Atropa belladonna), Jimson weed (Datura stramonium) and mandrake (Mandragora officinarum). Atropine is a competitive, nonselective antagonist of the muscarinic acetylcholine receptors and produces counteractive effects on the “rest and digest” activity of glands regulated by the parasympathetic nervous system. Atropine’s physiological effects include increasing firing of the sinoatrial node (SA) and conduction through the atrioventricular node (AV) of the heart, opposing the actions of the vagus nerve (which results in an increased heart rate), blocking acetylcholine receptor sites, dilation of the pupil, decreasing bronchial and salivary secretions, and relaxation of bronchial, intestinal and other smooth muscles. In medicine, it is used in opthalmology to dilate the pupil and in efforts of resuscitation in the treatment of bradycardia and cardiac arrest.