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Details

Stereochemistry ACHIRAL
Molecular Formula C17H23N3O.C4H4O4
Molecular Weight 401.4562
Optical Activity NONE
Defined Stereocenters 0 / 0
E/Z Centers 1
Charge 0

SHOW SMILES / InChI
Structure of PYRILAMINE MALEATE

SMILES

OC(=O)\C=C/C(O)=O.COC1=CC=C(CN(CCN(C)C)C2=CC=CC=N2)C=C1

InChI

InChIKey=JXYWFNAQESKDNC-BTJKTKAUSA-N
InChI=1S/C17H23N3O.C4H4O4/c1-19(2)12-13-20(17-6-4-5-11-18-17)14-15-7-9-16(21-3)10-8-15;5-3(6)1-2-4(7)8/h4-11H,12-14H2,1-3H3;1-2H,(H,5,6)(H,7,8)/b;2-1-

HIDE SMILES / InChI

Molecular Formula C4H4O4
Molecular Weight 116.0722
Charge 0
Count
MOL RATIO 1 MOL RATIO (average)
Stereochemistry ACHIRAL
Additional Stereochemistry No
Defined Stereocenters 0 / 0
E/Z Centers 1
Optical Activity NONE

Molecular Formula C17H23N3O
Molecular Weight 285.384
Charge 0
Count
MOL RATIO 1 MOL RATIO (average)
Stereochemistry ACHIRAL
Additional Stereochemistry No
Defined Stereocenters 0 / 0
E/Z Centers 0
Optical Activity NONE

Description

Pyrilamine (also known as Mepyramine) is a first generation antihistamine, targeting the H1 receptor. However, it rapidly permeates the brain and so often causes drowsiness as a side effect. It is used in over-the-counter combination products for colds and menstrual symptoms. Mepyramine is a histamine H1 receptor inverse agonist. It binds to a G protein-coupled form of the receptor and promotes a G protein-coupled inactive state of the H1 receptor that interferes with the Gq/11-mediated signaling. Mepyramine competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The sedative properties of Mepyramine occur at the subcortical level of the CNS. It has mild hypnotic properties and some local anesthetic action and is used for allergies (including skin eruptions) both parenterally and locally. It is a common ingredient of cold remedies.

CNS Activity

Originator

Approval Year

Targets

Primary TargetPharmacologyConditionPotency
0.8 nM [Ki]

Conditions

ConditionModalityTargetsHighest PhaseProduct
Primary
Phenylephrine/ pyrilamine
Primary
Phenylephrine/ pyrilamine
Primary
MIDOL PMS

Cmax

ValueDoseCo-administeredAnalytePopulation
36.6 ng/mL
300 mg single, intravenous
PYRILAMINE plasma
Equus caballus

AUC

ValueDoseCo-administeredAnalytePopulation
54.6 ng × h/mL
300 mg single, intravenous
PYRILAMINE plasma
Equus caballus

T1/2

ValueDoseCo-administeredAnalytePopulation
0.85 h
300 mg single, intravenous
PYRILAMINE plasma
Equus caballus

Doses

Overview

CYP3A4CYP2C9CYP2D6hERG


OverviewOther

Other InhibitorOther SubstrateOther Inducer

Drug as perpetrator​

Drug as victim

Tox targets

PubMed

Sample Use Guides

In Vivo Use Guide
Usual Adult Dose for Allergic Rhinitis phenylephrine-pyrilamine 25 mg-60 mg oral tablet: 1 or 2 tablets orally every 12 hours as needed. phenylephrine-pyrilamine 20 mg-16 mg oral tablet, chewable, extended release: 1 or 2 tablets orally every 12 hours as needed. phenylephrine-pyrilamine 5 mg-16 mg/5 mL oral suspension, extended release: 5 to 10 mL orally every 12 hours as needed. phenylephrine-pyrilamine 9 mg-12 mg/5 mL oral suspension, extended release: 5 to 10 mL orally every 12 hours as needed, not to exceed 20 mL in 24 hours.
Route of Administration: Oral
In Vitro Use Guide
Pretreatment with the histamine H1 receptor antagonist pyrilamine (1 uM) could reduce the beta-lactoglobulin-induced response in the in vitro guinea pig mesenteric preparation
Substance Class Chemical
Record UNII
R35D29L3ZA
Record Status Validated (UNII)
Record Version