atropine

atropine
Drug name	Atropine
Tradename	Atropen, Sal-Tropine
Routes of administration	Intravenous, intramuscular, subcutaneous, ophthalmic, inhalation
Legal status	Prescription-only medication
Bioavailability	Variable by route
Metabolism	Hepatic (partial)
Onset	Rapid (parenteral)
Duration of action	Variable

atropine is an antimuscarinic alkaloid derived from members of the Solanaceae family and used widely in clinical practice as a parasympatholytic agent. It acts at peripheral and central muscarinic acetylcholine receptors to reduce vagal tone, dilate pupils, reduce secretions, and antagonize organophosphate poisoning effects. The compound has influenced emergency medicine, ophthalmology, anesthesiology, and toxicology across the twentieth and twenty‑first centuries.

History

Atropine's history intersects with classical and modern figures and institutions. Early descriptions of nightshade plants appear in works by Hippocrates and Dioscorides; later botanical classification involved Carl Linnaeus and the development of binomial nomenclature. Interest in anticholinergic plants grew during the Renaissance among physicians such as Paracelsus and naturalists like John Ray. The isolation of tropane alkaloids occurred in the nineteenth century amid chemical advances led by Friedrich Sertürner-era peers; later organic chemists including Robert Robinson and Richard Willstätter elucidated alkaloid structures. Atropine entered modern therapeutics during the nineteenth and early twentieth centuries as anesthetic practice evolved at institutions like Guy's Hospital and Johns Hopkins Hospital. Military medicine during the World Wars and conflicts involving agents like those discussed at the Geneva Conventions accelerated research into antidotes for nerve agents, influencing policies at organizations such as the World Health Organization and Centers for Disease Control and Prevention.

Pharmacology

Atropine is a competitive antagonist at muscarinic acetylcholine receptors (M1–M5), discovered as receptor pharmacology matured in studies by researchers connected with Sir Henry Hallett Dale and Otto Loewi. Receptor classification and structure–function relationships were advanced by work at institutions like the Max Planck Society and universities such as Harvard University and University of Cambridge. Antagonism at M2 receptors in the heart increases heart rate, while blockade at M3 receptors affects smooth muscle and secretory glands; insights into G protein‑coupled receptor signaling were refined by laboratories associated with Nobel Prize laureates including Brian K. Kobilka and Robert J. Lefkowitz. Pharmacodynamic profiles were characterized in preclinical models from universities like University of Oxford and Columbia University.

Medical uses

Clinically, atropine is used in resuscitation algorithms promulgated by bodies including the American Heart Association and European Resuscitation Council for bradycardia management, and it features in toxicology protocols advised by American Academy of Clinical Toxicology. In ophthalmology, ophthalmic atropine sulfate is used for cycloplegia and mydriasis in settings taught at institutions such as Moorfields Eye Hospital and Bascom Palmer Eye Institute. Anesthesia guidelines from societies such as the American Society of Anesthesiologists describe atropine for anticholinergic prophylaxis and treatment of vagal reflexes during surgery at centers like Mayo Clinic and Cleveland Clinic. Atropine is a core antidote in organophosphate and nerve agent management alongside oximes informed by research from defense establishments including the United States Army Medical Research Institute of Chemical Defense.

Adverse effects and toxicity

Antimuscarinic effects manifest as dry mouth, blurred vision, photophobia, urinary retention, tachycardia, and central nervous system disturbances; clinical descriptions appear in textbooks used at Johns Hopkins University and Stanford University. Severe toxicity, seen in overdose or exposure to tropane-containing plants, can cause delirium, hyperthermia, and coma; historical case series were reported from hospitals like Bellevue Hospital and analyzed in journals affiliated with The Lancet and New England Journal of Medicine. Management protocols involve supportive care, benzodiazepines recommended by organizations such as American Psychiatric Association for agitation, and physostigmine as a cholinesterase inhibitor in selected settings per guidance from European Medicines Agency and national toxicology centers.

Pharmacokinetics

Pharmacokinetic characterization has been performed in clinical pharmacology units at universities like University College London and McGill University. Atropine is well absorbed via mucous membranes and parenteral routes, crosses the blood–brain barrier, and is partially metabolized hepatically; elimination kinetics were detailed in studies conducted by research groups associated with National Institutes of Health and Food and Drug Administration regulatory science programs. Dosing adjustments and monitoring practices reflect pharmacopeial standards referenced by agencies such as United States Pharmacopeia and European Pharmacopoeia.

Chemistry and biosynthesis

Atropine is a racemic mixture of tropic acid esters of tropane alkaloids related to compounds studied by chemists at institutions like ETH Zurich and University of Göttingen. The biosynthesis in Solanaceae species, including Atropa belladonna, Datura stramonium, and Hyoscyamus niger, has been elucidated through plant biochemistry research at botanical gardens such as the Royal Botanic Gardens, Kew and universities like University of California, Berkeley. Key enzymatic steps involve ornithine and arginine metabolism, tropane skeleton formation, and esterification with tropic acid; pathway genes have been characterized in studies collaborating with centers such as Max Planck Institute for Chemical Ecology.

Society and culture

Atropine and its source plants have cultural and historical roles referenced in art and literature connecting to figures like William Shakespeare and folk practices documented in regional herbals housed at libraries such as the British Library and Library of Congress. Regulation, supply, and medical training concerning atropine intersect with policies and curricula from organizations including World Health Organization, American Medical Association, and national health ministries. Contemporary discussions about availability for emergency preparedness involve collaborations among agencies like Federal Emergency Management Agency and research institutions such as Johns Hopkins Bloomberg School of Public Health.

Category:Antimuscarinic alkaloids