fenfluramine
noun
fen·flur·amine
ˌfen-ˈflu̇r-ə-ˌmēn 
: an anorectic amphetamine derivative C12H16F3N with little stimulant effect on the central nervous system formerly used in the form of its hydrochloride to treat obesity but no longer used due to its association with heart valve disease see fen-phen sense 1
Examples of fenfluramine in a Sentence
Recent Examples on the Web
These cases were reported with fenfluramine or the related dexfenfluramine alone, but never with phentermine alone (phentermine remains on the market).
—
Dr. Keith Roach, oregonlive, 28 Aug. 2023
Subsequent studies estimated that seven out of 10,000 people who took fenfluramine or fen-phen for less than four months developed valve disease, while 35 in 10,000 people who took fenfluramine or fen-phen for more than four months developed valve disease.
—Dr. Keith Roach, oregonlive, 28 Aug. 2023
So, why not just use fenfluramine in humans?
—Jennifer Walter, Discover Magazine, 11 Dec. 2019
One of the drugs in the combination known as fen-phen (a combination of fenfluramine and phentermine) was famously withdrawn in 1997 for damaging patients' heart valves.
—Karen Weintraub, USA TODAY, 20 Feb. 2023
Sure enough, fenfluramine activated the brain's receptors with a flood of serotonin, just like MDMA.
—Jennifer Walter, Discover Magazine, 11 Dec. 2019
In 1997, weight loss drug fenfluramine/phentermine (fen-phen) was pulled off the market after it was found to cause heart problems.
—Alexandra Ossola, Quartz, 19 June 2022
Belviq is chemically similar to fenfluramine, which was removed from the market after the fen-phen heart valve problems.
—John Fauber, Milwaukee Journal Sentinel, 22 Aug. 2021
Lingering safety doubts persist after several high-profile withdrawals, including the combination drug fenfluramine/phentermine in 1997, Meridia (sibutramine) in 2010, and Belviq (lorcaserin) in early 2020.
—Joshua Cohen, Forbes, 5 June 2021
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Dr. Keith Roach, oregonlive, 28 Aug. 2023
Subsequent studies estimated that seven out of 10,000 people who took fenfluramine or fen-phen for less than four months developed valve disease, while 35 in 10,000 people who took fenfluramine or fen-phen for more than four months developed valve disease.
—Dr. Keith Roach, oregonlive, 28 Aug. 2023
So, why not just use fenfluramine in humans?
—Jennifer Walter, Discover Magazine, 11 Dec. 2019
One of the drugs in the combination known as fen-phen (a combination of fenfluramine and phentermine) was famously withdrawn in 1997 for damaging patients' heart valves.
—Karen Weintraub, USA TODAY, 20 Feb. 2023
Sure enough, fenfluramine activated the brain's receptors with a flood of serotonin, just like MDMA.
—Jennifer Walter, Discover Magazine, 11 Dec. 2019
In 1997, weight loss drug fenfluramine/phentermine (fen-phen) was pulled off the market after it was found to cause heart problems.
—Alexandra Ossola, Quartz, 19 June 2022
Belviq is chemically similar to fenfluramine, which was removed from the market after the fen-phen heart valve problems.
—John Fauber, Milwaukee Journal Sentinel, 22 Aug. 2021
Lingering safety doubts persist after several high-profile withdrawals, including the combination drug fenfluramine/phentermine in 1997, Meridia (sibutramine) in 2010, and Belviq (lorcaserin) in early 2020.
—Joshua Cohen, Forbes, 5 June 2021
Cite this Entry
“Fenfluramine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fenfluramine. Accessed 18 Jul. 2025.
Copy CitationMedical Definition
fenfluramine
noun
fen·flur·amine
ˌfen-ˈflu̇r-ə-ˌmēn
: an anorectic amphetamine derivative C12H16F3N with little stimulant effect on the central nervous system formerly used in the form of its hydrochloride to treat obesity but no longer used due to its association with heart valve disease see dexfenfluramine, fen-phen sense 1
Love words? Need even more definitions?
Merriam-Webster unabridged
Share