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Identification
Name Pemirolast
Accession Number DB00885 (APRD00394)
Type small molecule
Groups approved
Description

Pemirolast potassium is a slightly yellow powder that is soluble in water. It is a mast cell stabilizer that acts as an antiallergic agent. As an ophthalmic aqueous sterile solution, pemirolast is used for the prevention of itching of the eyes caused by allergies such as hay fever, and allergic conjunctivitis. Pemirolast is potentially useful for prophylaxis of pulmonary hypersensitivity reactions to drugs such as paclitaxel.
Structure Thumb
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Display: 2D Structure | 3D Structure
Synonyms
Pemirolast Potassium
Pemirolastum [INN-Latin]
Pemiroplast Potassium
Salts Not Available
Brand names
Name Company
Alamast
Brand mixtures Not Available
Categories
  • Antipruritics
  • Anti-Allergic Agents
  • Histamine Antagonists
  • Ophthalmics
CAS number 100299-08-9
Weight Average: 228.2101
Monoisotopic: 228.075958908
Chemical Formula C10H8N6O
InChI Key InChIKey=HIANJWSAHKJQTH-UHFFFAOYSA-N
InChI
InChI=1S/C10H8N6O/c1-6-3-2-4-16-9(6)11-5-7(10(16)17)8-12-14-15-13-8/h2-5H,1H3,(H,12,13,14,15)
Plain Text
IUPAC Name
9-methyl-3-(2H-1,2,3,4-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one
SMILES
CC1=CC=CN2C(=O)C(=CN=C12)C1=NNN=N1
Plain Text
Mass Spec Not Available
Taxonomy
Kingdom Organic
Classes
  • Pyridines and Derivatives
  • Pyrimidines and Derivatives
Substructures
  • Pyridines and Derivatives
  • Pyrimidines and Derivatives
  • Tetrazoles
  • Heterocyclic compounds
  • Aromatic compounds
  • Imines
  • Cyanamides
Pharmacology
Indication For the prevention of itching of the eyes caused by allergies such as hay fever, and allergic conjunctivitis
Pharmacodynamics Pemirolast is used for the prophylactic treatment of itching of the eye associated with allergic conjunctivitis. Pemirolast potassium is a mast cell stabilizer that inhibits the in vivo Type I immediate hypersensitivity reaction. Pemirolast inhibits the antigen-induced release of inflammatory mediators (e.g., histamine, leukotriene C4, D4, E4) from human mast cells. Allergic reactions lead to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis and vasodilatation (allowing blood fluids to enter the area to cause swelling). Pemirolast is a histamine H1 antagonist. It competes with histamine for the normal H1-receptor sites on effector cells of blood vessels to provide effective, temporary relief of watery and itchy eyes.
Mechanism of action Pemirolast binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. Pemirolast has also been observed to inhibit antigen-stimulated calcium ion influx into mast cells through the blockage of calcium channels. Pemirolast inhibits the chemotaxis of eosinophils into ocular tissue, and prevents inflammatory mediator release from human eosinophils.
Absorption Not Available
Volume of distribution Not Available
Protein binding Not Available
Metabolism
Hepatic (Ophthalmic)
Route of elimination Following topical administration, about 10-15% of the dose was excreted unchanged in the urine.
Half life 4.5 hours (Ophthalmic)
Clearance Not Available
Toxicity Not Available
Affected organisms
  • Humans and other mammals
Pathways Not Available
Pharmacoeconomics
Manufacturers
  • Santen inc
Packagers
Dosage forms
Form Route Strength
Solution / drops Ophthalmic
Prices
Unit description Cost Unit
Alamast 0.1% drops 11.39 USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Country Patent Number Approved Expires (estimated)
United States 5034230 1994-07-02 2011-07-02
Properties
State solid
Experimental Properties
Property Value Source
logP 0 Not Available
Predicted Properties
Property Value Source
water solubility 4.62e-01 g/l ALOGPS
logP 0.13 ALOGPS
logP 1.46 ChemAxon
logS -2.7 ALOGPS
pKa (strongest acidic) 5.8 ChemAxon
pKa (strongest basic) -1.4 ChemAxon
physiological charge -1 ChemAxon
hydrogen acceptor count 5 ChemAxon
hydrogen donor count 1 ChemAxon
polar surface area 87.13 ChemAxon
rotatable bond count 1 ChemAxon
refractivity 63.35 ChemAxon
polarizability 21.96 ChemAxon
References
Synthesis Reference Not Available
General Reference
  1. Tinkelman DG, Berkowitz RB: A pilot study of pemirolast in patients with seasonal allergic rhinitis. Ann Allergy. 1991 Feb;66(2):162-5. Pubmed
External Links
Resource Link
KEGG Drug D01088 Link_out
PubChem Compound 57697 Link_out
PubChem Substance 46509034 Link_out
ChemSpider 51990 Link_out
Therapeutic Targets Database DAP001064 Link_out
PharmGKB PA164781018 Link_out
RxList http://www.rxlist.com/cgi/generic/alamast.htm Link_out
Drugs.com http://www.drugs.com/cdi/pemirolast.html Link_out
ATC Codes Not Available
AHFS Codes Not Available
PDB Entries Not Available
FDA label show (372 KB)
MSDS Not Available
Interactions
Drug Interactions Searched, but no interactions found.
Food Interactions Not Available
Comments
Drug created on June 13, 2005 07:24 / Updated on February 08, 2013 16:19