Atropiinia

Atropine is a tropane alkaloid derived from plants of the Solanaceae family, most notably Atropa belladonna (deadly nightshade), as well as Datura and Hyoscyamus species. It is used in medicine as a competitive antagonist of muscarinic acetylcholine receptors (M1–M5), thereby inhibiting parasympathetic nerve impulses. In pharmacology, atropine exists as the racemate known as atropine sulfate in many therapeutic preparations. It is capable of crossing the blood–brain barrier, which can produce central as well as peripheral effects.

In clinical use, atropine serves several roles. It is employed as a mydriatic agent in ophthalmology to dilate pupils for examination or surgery, and as an antisialogogue to reduce secretions during anesthesia. It is used to treat symptomatic bradycardia and to counteract muscarinic effects of cholinergic poisoning. A key indication is its use as an antidote in organophosphate or nerve agent poisoning, typically combined with pralidoxime. It can be administered intravenously, intramuscularly, or topically (eye drops), depending on the indication and desired onset of action.

Common adverse effects reflect its anticholinergic action and may include dry mouth, blurred vision with photophobia, urinary retention, constipation, tachycardia, and confusion or delirium, especially in elderly patients. Contraindications include narrow-angle glaucoma, severe tachyarrhythmias, intestinal obstruction, and certain myasthenic conditions. Caution is advised during pregnancy and in the elderly, and concurrent use with other anticholinergic agents can potentiate effects.