Triparanol

Triparanol

Clinical data
ATC code	None
Identifiers
IUPAC name 2-(4-Chlorophenyl)-1-[4-[2-(diethylamino)ethoxy]phenyl]-1-(4-methylphenyl)ethanol
Synonyms	Metasqualene
CAS Number	78-41-1
PubChem CID	6536
ChemSpider	6288
UNII	63S8C3RXGS
ChEBI	CHEBI:135714
Chemical and physical data
Formula	C27H32ClNO2
Molar mass	438.00148 g/mol
3D model (JSmol)	Interactive image
SMILES CCN(CC)CCOC1=CC=C(C=C1)C(CC2=CC=C(C=C2)Cl)(C3=CC=C(C=C3)C)O
InChI InChI=1S/C27H32ClNO2/c1-4-29(5-2)18-19-31-26-16-12-24(13-17-26)27(30,23-10-6-21(3)7-11-23)20-22-8-14-25(28)15-9-22/h6-17,30H,4-5,18-20H2,1-3H3 Key:SYHDSBBKRLVLFF-UHFFFAOYSA-N

Triparanol (INN, BAN) (brand and developmental code names MER/29, as well as many other brand names), patented in 1959 and introduced in the United States in 1960, was the first synthetic cholesterol-lowering drug. It was withdrawn in 1962 due to severe adverse effects such as nausea and vomiting, vision loss due to irreversible cataracts, alopecia, skin disorders (e.g., dryness, itching, peeling, and "fish-scale" texture), and accelerated atherosclerosis and is now considered to be obsolete.

The drug acts by inhibiting 24-dehydrocholesterol reductase, which catalyzes the final step of cholesterol biosynthesis, the conversion of desmosterol into cholesterol. This results in tissue accumulation of desmosterol, which in turn is responsible for the side effects of triparanol. Unlike statins, triparanol does not inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, and in contrast to triparanol, statins can significantly lower cholesterol levels without resulting in accumulation of intermediates like desmosterol. The developmental code name of triparanol, MER/29, became so well-known that it became the registered trade name of the drug.