epinephrine
noun
epi·neph·rine
ˌe-pə-ˈne-frən 
variants
or less commonly epinephrin
: a crystalline sympathomimetic hormone C9H13NO3 that is the principal blood-pressure raising hormone secreted by the medulla of the adrenal glands, is prepared from adrenal extracts or made synthetically, and is used medicinally especially to stimulate the heart during cardiac arrest and to treat life-threatening allergic reactions
called also adrenaline
Examples of epinephrine in a Sentence
Recent Examples on the Web
The doctor rushed her to a room without checking her in, saw her blood pressure was low, and administered two epinephrine injections and IV fluids, Toska said.
—
Andrew Jones, Miami Herald, 28 Apr. 2026
Research found that most EpiPens retain 100% of their epinephrine for up to 6 months after their expiration date.
—Carrie Madormo, Verywell Health, 22 Apr. 2026
Using epinephrine early — before the reaction gets worse — can keep a reaction from becoming life-threatening.
—Dr. Sonja O'Leary, Boston Herald, 29 Mar. 2026
On the morning of March 14, hospital staff noted his tongue had swollen and administered epinephrine.
—Bo Evans, CBS News, 17 Mar. 2026
See All Example Sentences for epinephrine
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Andrew Jones, Miami Herald, 28 Apr. 2026
Research found that most EpiPens retain 100% of their epinephrine for up to 6 months after their expiration date.
—Carrie Madormo, Verywell Health, 22 Apr. 2026
Using epinephrine early — before the reaction gets worse — can keep a reaction from becoming life-threatening.
—Dr. Sonja O'Leary, Boston Herald, 29 Mar. 2026
On the morning of March 14, hospital staff noted his tongue had swollen and administered epinephrine.
—Bo Evans, CBS News, 17 Mar. 2026
See All Example Sentences for epinephrine
Cite this Entry
“Epinephrine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epinephrine. Accessed 5 May. 2026.
Copy CitationMedical Definition
epinephrine
noun
epi·neph·rine
variants
also epinephrin
: a colorless crystalline sympathomimetic hormone C9H13NO3 that is the principal blood-pressure-raising hormone secreted by the adrenal medulla, is prepared from adrenal extracts or made synthetically, and is used medicinally especially to stimulate the heart during cardiac arrest and to treat life-threatening allergic reactions
called also adrenaline
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