Diphenhydramine methylbromideProduct ingredient for Diphenhydramine

Name
Diphenhydramine methylbromide
Drug Entry
Diphenhydramine

Diphenhydramine - perhaps known most commonly as its brand name formulation Benadryl - is a first-generation H1 receptor antihistamine that is used extensively for the treatment of seasonal allergies, insect bites and stings, and rashes 9,10,11,17. However, it also has antiemetic, antitussive, hypnotic, and antiparkinson properties 11,16. As histamine receptors exist both peripherally and in the central nervous system, diphenhydramine has been shown to cause sedation due to its competitive antagonism of histamine H1 receptors within the central nervous system 9,10,11,17,5. While its use in allergy therapy can sometimes fall out of favor due to its sedative effect, diphenhydramine has been repurposed for use within many non-prescription over-the-counter sleep aids and cough-and-cold medications that have been marketed for "night time" use 9,12,13.

Diphenhydramine is also used in combination with 8-chlorotheophylline as the anti-nausea drug Dimenhydrinate where it is utilized primarily for its antagonism of H1 histamine receptors within the vestibular system 4.

Diphenhydramine has also been shown to be implicated in a number of neurotransmitter systems that affect behaviour including dopamine, norepinephrine, serotonin, acetylcholine, and opioid 3. As a result, diphenhydramine is being investigated for its anxiolytic and anti-depressant properties.

Accession Number
DBSALT002478
Structure
Synonyms
Mefenidramium bromide
UNII
UJO67AO8YI
CAS Number
31065-89-1
Weight
Average: 350.3
Monoisotopic: 349.104127
Chemical Formula
C18H24BrNO
InChI Key
BDQPXVWYFLTETB-UHFFFAOYSA-M
InChI
InChI=1S/C18H24NO.BrH/c1-19(2,3)14-15-20-18(16-10-6-4-7-11-16)17-12-8-5-9-13-17;/h4-13,18H,14-15H2,1-3H3;1H/q+1;/p-1
IUPAC Name
[2-(diphenylmethoxy)ethyl]trimethylazanium bromide
SMILES
[Br-].C[N+](C)(C)CCOC(C1=CC=CC=C1)C1=CC=CC=C1
ChemSpider
8581024
Predicted Properties
PropertyValueSource
Water Solubility5.82e-05 mg/mLALOGPS
logP-0.81ALOGPS
logP-0.51Chemaxon
logS-6.8ALOGPS
pKa (Strongest Basic)-4.3Chemaxon
Physiological Charge1Chemaxon
Hydrogen Acceptor Count1Chemaxon
Hydrogen Donor Count0Chemaxon
Polar Surface Area9.23 Å2Chemaxon
Rotatable Bond Count6Chemaxon
Refractivity95.84 m3·mol-1Chemaxon
Polarizability31.99 Å3Chemaxon
Number of Rings2Chemaxon
Bioavailability1Chemaxon
Rule of FiveYesChemaxon
Ghose FilterNoChemaxon
Veber's RuleYesChemaxon
MDDR-like RuleNoChemaxon