General
Preferred name
LORATADINE
Synonyms
Loratidine ()
SCH 29851 ()
Loratadine (SCH29851) ()
Alavert,Claritin,SCH29851 ()
Hay-Rite ()
Roletra ()
Clarityn Rapide ()
Claritin Reditabs ()
Claritin ()
SCH-29851 ()
Clarityne ()
NSC-758628 ()
Alavert ()
Claritin Hives Relief ()
Loratadine Redidose ()
Claritin-D ()
Children's Claritin ()
Clarityn ()
BAY76-2211 ()
Claritin Hives Relief Reditab ()
Loratadine-d5 ()
Loratadine-d4 ()
P&D ID
PD000883
CAS
79794-75-5
1020719-57-6
2748435-73-4
Tags
prodrug
natural product
drug
available
Approved by
FDA
First approval
1993
Drug Status
investigational
approved
Drug indication
Allergy
Antihistaminic
Allergic rhinitis
Max Phase
Phase 4
Structure
Probe scores
P&D probe-likeness score
[[ v.score ]]%
Structure formats
[[ format ]]
[[ compound[format === 'MOL' ? 'molblock' : format.toLowerCase()] ]]
Description
(extracted from source data)
ABSORPTION Loratadine is rapidly absorbed and achieves peak plasma concentration in 1-2 hours, while it's main metabolite achieves peak plasma concentration in 3-4 hours.[A176438]
PHARMACODYNAMICS As a 2nd generation antihistamine, loratadine is selective for peripheral H1 receptors allowing it to effectively treat patients with allergic rhinitis or chronic urticaria. [A5506] Loratadine demonstrates poor penetration into the blood brain barrier and lacks affinity for CNS receptors explaining it's lack of overall CNS depressant effects including drowsiness, sedation, and impaired psychomotor function. [A5506]
INDICATION Loratadine is a 2nd generation antihistamine and is typically used to manage symptoms of allergic rhinitis, wheal formation and urticaria.[A176435][A176438] Unlike 1st generation antihistamines, loratadine is non-sedating since it has minimal effect on the central nervous system with only a small amount entering the brain. [A176438]
ROE Over a 10 day period, 40% of loratadine is excreted in the urine, while 42% is eliminated in the faeces.[F4154]
TOXICITY Second generation antihistamines such as loratadine have very few adverse effects; however, insomnia, headache, fatigue, drowsiness and rash have been reported.[A176441] Symptoms of loratadine overdose include gastrointestinal side effects, agitation, drowsiness, tachycardia, and headache. [A176441] It is advised to obtain an ECG in the event of loratadine overdose.[A176441]
METABOLISM Loratadine undergoes extensive first pass metabolism in the liver and is primarily metabolized by CYP enzymes including CYP3A4, CYP2D6, CYP1A1, CYP2C19. CYP1A2, CYP2B6, CYP2C9 and CYP3A5 play a smaller role in loratadine metabolism. [A38842][A176444] CYP3A4 and CYP2D6 are largely responsible for metabolizing loratadine to it's primary metabolite, descarbethoxyloratadine, which is more potent pharmacological activity compared to it's parent drug .[A176438][A176444]
HALF-LIFE The elimination half life is approximately 10 hours for loratadine and 20 hours for descarbethoxyloratadine.[A176438]
METABOLISM Loratadine undergoes extensive first pass metabolism in the liver and is primarily metabolized by CYP enzymes including CYP3A4, CYP2D6, CYP1A1, CYP2C19. CYP1A2, CYP2B6, CYP2C9 and CYP3A5 play a smaller role in loratadine metabolism. [A38842][A176444] CYP3A4 and CYP2D6 are largely responsible for metabolizing loratadine to it's primary metabolite, descarbethoxyloratadine, which is more potent pharmacological activity compared to it's parent drug .[A176438][A176444];
DESCRIPTION Loratidine is an antihistamine; peripheral H1 receptor antagonist; antiallergic agent. (GtoPdb)
MOA Loratadine binds to H1 histamine receptors found on the surface of various cells including epithelial cells, endothelial cells, eosinophils, neutrophils, airway cells, and vascular smooth muscle cells. [A176441] H1 histamine receptors fall under the wider umbrella of G-protein coupled receptors, therefore there is a balance of the active and inactive forms of H1 receptors at baseline.[A175060] Histamine causes cross linking on transmembrane domain sites III and V which stabilizes the active form of the receptor, while antihistamines bind at different sites on the H1 receptor, favouring the inactive form.[A176441] Given the mechanism of action, Loratadine should be referred to as an "inverse agonist" rather than a "histamine antagonist". [A176441][A175060]
DESCRIPTION Potent 5-HT2 antagonist (Tocris Bioactive Compound Library)
DESCRIPTION Peripheral H1 antagonist; antiallergic agent (Tocriscreen Plus)
DESCRIPTION H1 Histamine receptor antagonist (LOPAC library)
DESCRIPTION Peripheral H1 antagonist; antiallergic agent (Tocriscreen Total)
Cell lines
3
Organisms
5
Compound Sets
32
Axon Medchem Screening Library
1299
Cayman Chemical Bioactives
15625
25040
26759
ChEMBL Approved Drugs
CHEMBL998
ChEMBL Drugs
CHEMBL998
Concise Guide to Pharmacology 2017/18
7216
Concise Guide to Pharmacology 2019/20
7216
Concise Guide to Pharmacology 2021/22
7216
Concise Guide to Pharmacology 2023/24
7216
Drug Repurposing Hub
DrugBank
DB00455
DrugBank Approved Drugs
DB00455
DrugCentral
1605
DrugCentral Approved Drugs
1605
DrugMAP
DMF3AN7
DrugMAP Approved Drugs
DMF3AN7
DrugMatrix
Enamine BioReference Compounds
Guide to Pharmacology
7216
LOPAC library
LSP-MoA library (Laboratory of Systems Pharmacology)
CHEMBL998
MedChem Express Bioactive Compound Library
HY-17043
NCATS Inxight Approved Drugs
7AJO3BO7QN
NIH Clinical Collections (NCC)
NPC Screening Collection
Prestwick Chemical Library
ReFrame library
Selleckchem Bioactive Compound Library
Loratadine
TargetMol Bioactive Compound Library
T1097
The Spectrum Collection
Tocris Bioactive Compound Library
1944
Tocriscreen Plus
1944
Tocriscreen Total
External IDs
50
Properties
(calculated by RDKit )
Molecular Weight
382.14
Hydrogen Bond Acceptors
3
Hydrogen Bond Donors
0
Rotatable Bonds
1
Ring Count
4
Aromatic Ring Count
2
cLogP
4.89
TPSA
42.43
Fraction CSP3
0.36
Chiral centers
0.0
Largest ring
7.0
QED
0.7
Structural alerts
0
No structural alerts detected
Related compounds
Custom attributes
(extracted from source data)
Target Type
7-TM Receptors
Selectivity
H1
Pathway
GPCR/G protein
Immunology/Inflammation
Neuroscience
Anti-infection
Neuronal Signaling
Target
B(0)AT2
HRH1
H1 antagonist
Dengue virus
Flavivirus
Histamine Receptor
Primary Target
Histamine H1 Receptors
MOA
Antagonist
Histamine Receptor antagonist
Indication
allergic rhinitis, itching
Disease Area
allergy, neurology/psychiatry
Therapeutic Class
Antihistamines
Source data