Record Information
Version1.0
Creation Date2009-07-21 20:26:56 UTC
Update Date2026-05-14 16:39:21 UTC
Accession NumberCHEM002198
Identification
Common NameLoratadine
ClassSmall Molecule
Description
Loratadine is a tricyclic antihistamine, which has a selective and peripheral H1-antagonist action. It has a long-lasting effect and does not normally cause drowsiness because it does not readily enter the central nervous system; An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake; Loratadine is a drug used to treat allergies. It is marketed by Schering-Plough under several trade names such as Claritin, Clarityn or Claratyne depending on the market, by Lek as Lomilan and by Wyeth as Alavert. It is also available as a generic; Loratadine is a drug used to treat allergies. It is marketed by Schering-Plough under several trade names such as Claritin, Clarityn or Claratyne depending on the market, by Lek as Lomilan and by Wyeth as Alavert. It is also available as a generic. Its active metabolite, desloratadine, is also on the market, though loratadine itself is the only drug of its class available over the counter (at least in the U.S. as of 2005. Loratadine is available off the shelf in the UK.
Contaminant Sources
  • FooDB Chemicals
  • STOFF IDENT Compounds
  • T3DB toxins
  • ToxCast & Tox21 Chemicals
Contaminant Type
  • Amine
  • Anti-Allergic Agent
  • Antipruritic
  • Drug
  • Ester
  • Ether
  • Food Toxin
  • Histamine Antagonist
  • Histamine H1 Antagonist, Non-Sedating
  • Human Neurotoxin
  • Metabolite
  • Organic Compound
  • Organochloride
  • Synthetic Compound
Chemical Structure
Synonyms
ValueSource
4-(8-Chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl esterChEBI
AerotinaChEBI
AlarinChEBI
AlavertChEBI
AlerprivChEBI
AllerclearChEBI
CiveranChEBI
ClaratyneChEBI
ClaritinChEBI
LoracertChEBI
LoradamedChEBI
LoradexChEBI
LorastineChEBI
LoratadinaChEBI
LoratadinumChEBI
LoratyneChEBI
Wal-itinChEBI
4-(8-Chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylate ethyl esterGenerator
4-(8-Chloro-5,6-dihydro-11H-benzo(5,6)cyclohepta(1,2-b)pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl esterMeSH
ClariumMeSH
AmantadineHMDB
AnhissenHMDB
BonalergHMDB
ClaritineHMDB
ClaritynHMDB
ClarityneHMDB
CronopenHMDB
FlonidanHMDB
FristaminHMDB
HistaloranHMDB
KlaritinHMDB
LertamineHMDB
LisinoHMDB
LoranoxHMDB
LoratidineHMDB
Loratadine wyeth brandMeSH, HMDB
Wyeth brand OF loratadineMeSH, HMDB
Chemical FormulaC22H23ClN2O2
Average Molecular Mass382.883 g/mol
Monoisotopic Mass382.145 g/mol
CAS Registry Number79794-75-5
IUPAC Nameethyl 4-{13-chloro-4-azatricyclo[9.4.0.0^{3,8}]pentadeca-1(11),3(8),4,6,12,14-hexaen-2-ylidene}piperidine-1-carboxylate
Traditional Nameethyl 4-{13-chloro-4-azatricyclo[9.4.0.0^{3,8}]pentadeca-1(11),3(8),4,6,12,14-hexaen-2-ylidene}piperidine-1-carboxylate
SMILESCCOC(=O)N1CCC(CC1)=C1C2=C(CCC3=C1N=CC=C3)C=C(Cl)C=C2
InChI IdentifierInChI=1S/C22H23ClN2O2/c1-2-27-22(26)25-12-9-15(10-13-25)20-19-8-7-18(23)14-17(19)6-5-16-4-3-11-24-21(16)20/h3-4,7-8,11,14H,2,5-6,9-10,12-13H2,1H3
InChI KeyJCCNYMKQOSZNPW-UHFFFAOYSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as benzocycloheptapyridines. These are aromatic compounds containing a benzene ring and a pyridine ring fused to a seven membered carbocycle.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassBenzocycloheptapyridines
Sub ClassNot Available
Direct ParentBenzocycloheptapyridines
Alternative Parents
Substituents
  • Benzocycloheptapyridine
  • Piperidinecarboxylic acid
  • Aryl chloride
  • Aryl halide
  • Piperidine
  • Pyridine
  • Benzenoid
  • Heteroaromatic compound
  • Carbamic acid ester
  • Carbonic acid derivative
  • Azacycle
  • Hydrocarbon derivative
  • Organic oxide
  • Organooxygen compound
  • Organonitrogen compound
  • Organochloride
  • Organohalogen compound
  • Carbonyl group
  • Organopnictogen compound
  • Organic oxygen compound
  • Organic nitrogen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External DescriptorsNot Available
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Membrane
Biofluid LocationsNot Available
Tissue Locations
  • Brain
  • Central Nervous System
  • Skin
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateSolid
AppearanceWhite powder.
Experimental Properties
PropertyValue
Melting Point134-136°C
Boiling PointNot Available
Solubility0.000011 mg/ml
Predicted Properties
PropertyValueSource
Water Solubility0.013 g/LALOGPS
logP4.8ALOGPS
logP4.55ChemAxon
logS-4.5ALOGPS
pKa (Strongest Basic)4.33ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area42.43 ŲChemAxon
Rotatable Bond Count2ChemAxon
Refractivity116.98 m³·mol⁻¹ChemAxon
Polarizability41.68 ųChemAxon
Number of Rings4ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectra
Toxicity Profile
Route of ExposureRapidly absorbed following oral administration (40% bioavailability)
Mechanism of ToxicityLoratadine competes with free histamine and exhibits specific, selective peripheral H1 antagonistic activity. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms (eg. nasal congestion, watery eyes) brought on by histamine. Loratadine has low affinity for cholinergic receptors and does not exhibit any appreciable alpha-adrenergic blocking activity in-vitro. Loratadine also appears to suppress the release of histamine and leukotrienes from animal mast cells, and the release of leukotrienes from human lung fragments, although the clinical importance of this is unknown.
MetabolismHepatic Half Life: 8.4 hours
Toxicity ValuesLD50=mg/kg (orally in rat)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesUsed to treat allergies. A self-medication that is used alone or in combination with pseudoephedrine sulfate for the symptomatic relief of seasonal allergic rhinitis. Also used for the symptomatic relief of pruritus, erythema, and urticaria associated with chronic idiopathic urticaria in patients (not for children under 6 unless directed by a clincian).
Minimum Risk LevelNot Available
Health EffectsLoratadine causes sedation and psychomotor impairment.
SymptomsSomnolence, tachycardia, and headache. Psychomotor impairment, and antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastrointestinal disturbances are the most common side effects.
TreatmentTreatment of overdosage would reasonably consist of emesis (ipecac syrup), except in patients with impaired consciousness, followed by the administration of activated charcoal to absorb any remaining drug. If vomiting is unsuccessful, or contraindicated, gastric lavage should be performed with normal saline. Saline cathartics may also be of value for rapid dilution of bowel contents. Loratadine is not eliminated by hemodialysis. It is not known if loratadine is eliminated by peritoneal dialysis. (15)
Concentrations
Not Available
External Links
DrugBank IDDB00455
HMDB IDHMDB0005000
FooDB IDFDB023577
Phenol Explorer IDNot Available
KNApSAcK IDNot Available
BiGG IDNot Available
BioCyc IDNot Available
METLIN ID1021
PDB IDNot Available
Wikipedia LinkLoratadine
Chemspider ID3820
ChEBI ID6538
PubChem Compound ID3957
Kegg Compound IDC06818
YMDB IDNot Available
ECMDB IDNot Available
References
Synthesis Reference

Alberto Stampa, Pelayo Camps, Gloria Rodriguez, Jordi Bosch, Maria del Carmen Onrubia, “Process for the preparation of loratadine.” U.S. Patent US6084100, issued July 04, 2000.

MSDSLink
General References
1. https://www.ncbi.nlm.nih.gov/pubmed/?term=15627436
2. https://www.ncbi.nlm.nih.gov/pubmed/?term=24134630
3. https://www.ncbi.nlm.nih.gov/pubmed/?term=31315424
4. https://www.ncbi.nlm.nih.gov/pubmed/?term=31576110
5. https://www.ncbi.nlm.nih.gov/pubmed/?term=32312261
6. https://www.ncbi.nlm.nih.gov/pubmed/?term=32694422
7. https://www.ncbi.nlm.nih.gov/pubmed/?term=32877950
8. https://www.ncbi.nlm.nih.gov/pubmed/?term=33550204
9. https://www.ncbi.nlm.nih.gov/pubmed/?term=33673552
10. https://www.ncbi.nlm.nih.gov/pubmed/?term=33963858
11. https://www.ncbi.nlm.nih.gov/pubmed/?term=34121623
12. https://www.ncbi.nlm.nih.gov/pubmed/?term=34306392
13. https://www.ncbi.nlm.nih.gov/pubmed/?term=7522069
14. Vilani, Frank J. Antihistaminic 11-(4-piperidylidene)-5H-benzo-(5,6)-cyclohepta-[1,2-b]-pyridines. U.S. (1981), 4 pp. CODEN: USXXAM US 4282233 19810804 CAN 95:203761 AN 1981:603761
15. Vilani, Frank J. Antihistaminic 11-(4-piperidylidene)-5H-benzo-(5,6)-cyclohepta-[1,2-b]-pyridines. U.S. (1981), 4 pp. CODEN: USXXAM US 4282233 19810804 CAN 95:203761 AN 1981:603761
16. Simons FE, Silver NA, Gu X, Simons KJ: Clinical pharmacology of H1-antihistamines in the skin. J Allergy Clin Immunol. 2002 Nov;110(5):777-83.
17. Green LB, Hornyak JE, Hurvitz EA: Amantadine in pediatric patients with traumatic brain injury: a retrospective, case-controlled study. Am J Phys Med Rehabil. 2004 Dec;83(12):893-7.
18. Purohit A, Melac M, Pauli G, Frossard N: Comparative activity of cetirizine and desloratadine on histamine-induced wheal-and-flare responses during 24 hours. Ann Allergy Asthma Immunol. 2004 Jun;92(6):635-40.
19. Kornhuber J, Quack G, Danysz W, Jellinger K, Danielczyk W, Gsell W, Riederer P: Therapeutic brain concentration of the NMDA receptor antagonist amantadine. Neuropharmacology. 1995 Jul;34(7):713-21.
20. Deep P, Dagher A, Sadikot A, Gjedde A, Cumming P: Stimulation of dopa decarboxylase activity in striatum of healthy human brain secondary to NMDA receptor antagonism with a low dose of amantadine. Synapse. 1999 Dec 15;34(4):313-8.
21. Strong DK, Eisenstat DD, Bryson SM, Sitar DS, Arbus GS: Amantadine neurotoxicity in a pediatric patient with renal insufficiency. DICP. 1991 Nov;25(11):1175-7.
22. Ramboer I, Bumtbacea R, Lazarescu D, Radu JR: Cetirizine and loratadine: a comparison using the ED50 in skin reactions. J Int Med Res. 2000 Mar-Apr;28(2):69-77.
23. Shiller AD, Burke DT, Kim HJ, Calvanio R, Dechman KG, Santini C: Treatment with amantadine potentiated motor learning in a patient with traumatic brain injury of 15 years' duration. Brain Inj. 1999 Sep;13(9):715-21.
24. Wilkinson R, Meythaler JM, Guin-Renfroe S: Neuroleptic malignant syndrome induced by haloperidol following traumatic brain injury. Brain Inj. 1999 Dec;13(12):1025-31.