Mepyramine

Mepyramine
Clinical data
Other namesPyrilamine; N-[2-(dimethylamino)ethyl]-N-[(4-methoxyphenyl)methyl]pyridin-2-amine
AHFS/Drugs.comInternational Drug Names
MedlinePlusa606008
Routes of
administration		oral, topical,
ATC code
Legal status
Legal status
Identifiers
  • N-(4-methoxybenzyl)-N',N'-dimethyl-N-pyridin-2-ylethane-1,2-diamine
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.001.912 Edit this at Wikidata
Chemical and physical data
FormulaC17H23N3O
Molar mass285.391 g·mol−1
3D model (JSmol)
  • O(c1ccc(cc1)CN(c2ncccc2)CCN(C)C)C
  • InChI=1S/C17H23N3O/c1-19(2)12-13-20(17-6-4-5-11-18-17)14-15-7-9-16(21-3)10-8-15/h4-11H,12-14H2,1-3H3 checkY
  • Key:YECBIJXISLIIDS-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Mepyramine, also known as pyrilamine, is a first generation antihistamine, targeting the H1 receptor as an inverse agonist.[1] Mepyramine rapidly permeates the brain, often causing drowsiness.[2] It is often sold as a maleate salt, pyrilamine maleate.

The medication has negligible anticholinergic activity, with 130,000-fold selectivity for the histamine H1 receptor over the muscarinic acetylcholine receptors (for comparison, diphenhydramine had 20-fold selectivity for the H1 receptor).[3]

It was patented in 1943 and came into medical use in 1949.[4] It was marketed under the names Histadyl, Histalon, Neo-Antergan, Neo-Pyramine, and Nisaval.[5] In the 1960s and 70s it was a very common component in over-the-counter sleep aids such as Alva-Tranquil, Dormin, Sedacaps, Sominex, Nytol, and many others.[5] The US FDA included it in the list of chemicals and compounds barred from use in over-the-counter nighttime sleep aid products in 1989.[6]

It is used in over-the-counter combination products to treat the common cold and menstrual symptoms such as Midol Complete.[7] It is also the active ingredient of the topical antihistamine creams Anthisan[8] and Neoantergan[1] sold for the treatment of insect bites, stings, and nettle rash.

  1. ^ a b Parsons ME, Ganellin CR (January 2006). "Histamine and its receptors". British Journal of Pharmacology. 147 (Suppl 1) (published 2 February 2009): S127–S135. doi:10.1038/sj.bjp.0706440. PMC 1760721. PMID 16402096.
  2. ^ "Mepyramine". drugbank.com. Retrieved 8 May 2021.
  3. ^ Kubo N, Shirakawa O, Kuno T, Tanaka C (March 1987). "Antimuscarinic effects of antihistamines: quantitative evaluation by receptor-binding assay". Japanese Journal of Pharmacology. 43 (3): 277–282. doi:10.1254/jjp.43.277. PMID 2884340.
  4. ^ Fischer J, Gannelin CR, eds. (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 545. ISBN 9783527607495.
  5. ^ a b Thornton WE (September 1977). "Sleep aids and sedatives". Journal of the American College of Emergency Physicians (JACEP). 6 (9): 408–412. doi:10.1016/S0361-1124(77)80006-3. PMID 330911.
  6. ^ 54 FR 6826
  7. ^ "Active Ingredients for Midol Complete". Bayer HealthCare LLC. Archived from the original on 2 December 2009. Retrieved 8 December 2009.
  8. ^ "Anthisan Cream - Patient Information Leaflet (PIL)". Medicines.org.