atropine

American  

[a-truh-peen, -pin] / ˈæ trəˌpin, -pɪn /

noun

Pharmacology.

1. a poisonous crystalline alkaloid, C 17 H 23 NO 3 , obtained from belladonna and other plants of the nightshade family, that prevents the response of various body structures to certain types of nerve stimulation: used chiefly to relieve spasms, to lessen secretions, and, topically, to dilate the pupil of the eye.

---

atropine British  

/ ˈætrəˌpiːn, ˈætrəpɪn, -pɪn /

noun

1. a poisonous alkaloid obtained from deadly nightshade, having an inhibitory action on the autonomic nervous system. It is used medicinally in pre-anaesthetic medication, to speed a slow heart rate, and as an emergency first-aid counter to exposure to chemical warfare nerve agents. Formula: C 17 H 23 NO 3

---

atropine Scientific  

/ ăt′rə-pēn′,-pĭn /

1. A poisonous, bitter, crystalline alkaloid derived from deadly nightshade and related plants. It is used as a drug to dilate the pupils of the eye and to inhibit muscle spasms. Chemical formula: C ₁₇ H ₂₃ NO ₃ .

---

Etymology

Origin of atropine

1830–40; < New Latin Atrop ( a ) belladonna genus (< Greek átropos; see Atropos) + -ine ²

Example Sentences

The U.S. is a global outlier, as there are approved versions of low-dose atropine in all other major markets.

From The Wall Street Journal • Dec. 28, 2025

But at very low concentrations, usually between 0.01 to 0.05 percent solution, atropine drops just before bed has been shown to slow the growth of the eyeball.

From National Geographic • Nov. 1, 2023

Current interventions to slow the progression include specialty pediatric contact lenses and FDA-approved eye drops containing atropine.

From Slate • Sep. 30, 2023

Despite its deadly potential, the nerve-gas antidote atropine sulphate can be extracted from it.

From BBC • Jul. 10, 2023

Mydriasis by atropine had no influence whatever on the squint, therefore, on December 31st, convex spectacles 2 D. were prescribed for permanent use.

From Schweigger on Squint A Monograph by Dr. C. Schweigger by Schweigger, C.