Astemizole

Identification

Summary

Astemizole is a second generation antihistamine used to treat allergy symptoms.

Generic Name
Astemizole
DrugBank Accession Number
DB00637
Background

Astemizole is a long-acting, non-sedating second generation antihistamine used in the treatment of allergy symptoms. It was withdrawn from market by the manufacturer in 1999 due to the potential to cause arrhythmias at high doses, especially when when taken with CYP inhibitors or grapefruit juice.

Type
Small Molecule
Groups
Approved, Withdrawn
Structure
Weight
Average: 458.5703
Monoisotopic: 458.248189839
Chemical Formula
C28H31FN4O
Synonyms
  • 1-(p-Fluorobenzyl)-2-((1-(2-(p-methoxyphenyl)ethyl)piperid-4-yl)amino)benzimidazole
  • 1-(p-Fluorobenzyl)-2-((1-(p-methoxyphenethyl)-4-piperidyl)amino)benzimidazole
  • Astemizol
  • Astémizole
  • Astemizole
  • Astemizolum
External IDs
  • BRN 4830190
  • R 42512
  • R 43,512
  • R43512

Pharmacology

Indication

Astemizole was indicated for use in the relieving allergy symptoms, particularly rhinitis and conjunctivitis. It has been withdrawn from the market however due to concerns of arrhythmias.

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Pharmacodynamics

Astemizole is a second generation H1-receptor antagonist. It does not significantly cross the blood brain barrier and therefore does not cause drowsiness or CNS depression at normal doses.

Mechanism of action

Astemizole competes with histamine for binding at H1-receptor sites in the GI tract, uterus, large blood vessels, and bronchial muscle. This reversible binding of astemizole to H1-receptors suppresses the formation of edema, flare, and pruritus resulting from histaminic activity. As the drug does not readily cross the blood-brain barrier and preferentially binds at H1 receptors in the peripehery rather than within the brain, CNS depression is minimal. Astemizole may also act on H3-receptors, producing adverse effects.

TargetActionsOrganism
AHistamine H1 receptor
antagonist
Humans
UVoltage-gated inwardly rectifying potassium channel KCNH2
inhibitor
Humans
UVoltage-gated delayed rectifier potassium channel KCNH1Not AvailableHumans
UMicrotubule-associated protein tauNot AvailableHumans
Absorption

Rapidly absorbed from the gastrointestinal tract.

Volume of distribution

Not Available

Protein binding

96.7%

Metabolism

Almost completely metabolized in the liver and primarily excreted in the feces.

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Route of elimination

Not Available

Half-life

1 day

Clearance

Not Available

Adverse Effects
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Toxicity

LD50=2052mg/kg in mice

Pathways
PathwayCategory
Astemizole H1-Antihistamine ActionDrug action
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
DrugInteraction
AbametapirThe serum concentration of Astemizole can be increased when it is combined with Abametapir.
AbataceptThe metabolism of Astemizole can be increased when combined with Abatacept.
AbemaciclibThe serum concentration of Abemaciclib can be increased when it is combined with Astemizole.
AbirateroneThe metabolism of Astemizole can be decreased when combined with Abiraterone.
AcalabrutinibThe metabolism of Astemizole can be decreased when combined with Acalabrutinib.
Food Interactions
  • Take on an empty stomach. Food decreases absorption.

Products

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International/Other Brands
Acemiz (Lupin) / Alerkin (Incobra) / Astemison / Astesen (Senosiain) / Hismanal (Janssen) / Histalong (Biofarma) / Lergibrumizol (Bruluart) / Stemiz (Cadila HC)
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
Hismanal - Tab 10mgTablet10 mg / tabOralJohnson & Johnson Merck Consumer Pharmaceuticals Of Canada1997-01-211999-03-04Canada flag
Hismanal Suspension 2mg/mlSuspension2 mg / mLOralJanssen Pharmaceutica, Division Of Janssen Ortho Inc.1984-12-311997-08-12Canada flag
Hismanal Tab 10mgTablet10 mg / tabOralJanssen Pharmaceutica, Division Of Janssen Ortho Inc.1984-12-311997-08-12Canada flag

Categories

ATC Codes
R06AX11 — Astemizole
Drug Categories
Chemical TaxonomyProvided by Classyfire
Description
This compound belongs to the class of organic compounds known as benzimidazoles. These are organic compounds containing a benzene ring fused to an imidazole ring (five member ring containing a nitrogen atom, 4 carbon atoms, and two double bonds).
Kingdom
Organic compounds
Super Class
Organoheterocyclic compounds
Class
Benzimidazoles
Sub Class
Not Available
Direct Parent
Benzimidazoles
Alternative Parents
Phenethylamines / Anisoles / Methoxybenzenes / Phenoxy compounds / Alkyl aryl ethers / Fluorobenzenes / Aralkylamines / N-substituted imidazoles / Aryl fluorides / Piperidines
show 6 more
Substituents
Alkyl aryl ether / Amine / Anisole / Aralkylamine / Aromatic heteropolycyclic compound / Aryl fluoride / Aryl halide / Azacycle / Azole / Benzenoid
show 23 more
Molecular Framework
Aromatic heteropolycyclic compounds
External Descriptors
piperidines, benzimidazoles (CHEBI:2896)
Affected organisms
  • Humans and other mammals

Chemical Identifiers

UNII
7HU6337315
CAS number
68844-77-9
InChI Key
GXDALQBWZGODGZ-UHFFFAOYSA-N
InChI
InChI=1S/C28H31FN4O/c1-34-25-12-8-21(9-13-25)14-17-32-18-15-24(16-19-32)30-28-31-26-4-2-3-5-27(26)33(28)20-22-6-10-23(29)11-7-22/h2-13,24H,14-20H2,1H3,(H,30,31)
IUPAC Name
1-[(4-fluorophenyl)methyl]-N-{1-[2-(4-methoxyphenyl)ethyl]piperidin-4-yl}-1H-1,3-benzodiazol-2-amine
SMILES
COC1=CC=C(CCN2CCC(CC2)NC2=NC3=CC=CC=C3N2CC2=CC=C(F)C=C2)C=C1

References

Synthesis Reference

Godelieve Irma Christine Maria Heylen, Cornelus Gerardus Maria Janssen, Jurzak Mirek, Henricus Petrus Martinus Maria Van Assouw, "Radiolabeled astemizole and method of making." U.S. Patent US07541476, issued June 02, 2009.

US07541476
General References
  1. Wang X, Hockerman GH, Green HW 3rd, Babbs CF, Mohammad SI, Gerrard D, Latour MA, London B, Hannon KM, Pond AL: Merg1a K+ channel induces skeletal muscle atrophy by activating the ubiquitin proteasome pathway. FASEB J. 2006 Jul;20(9):1531-3. Epub 2006 May 24. [Article]
  2. Chong CR, Chen X, Shi L, Liu JO, Sullivan DJ Jr: A clinical drug library screen identifies astemizole as an antimalarial agent. Nat Chem Biol. 2006 Aug;2(8):415-6. Epub 2006 Jul 2. [Article]
Human Metabolome Database
HMDB0014775
KEGG Drug
D00234
KEGG Compound
C06832
PubChem Compound
2247
PubChem Substance
46508569
ChemSpider
2160
BindingDB
24226
RxNav
42328
ChEBI
2896
ChEMBL
CHEMBL296419
ZINC
ZINC000000601274
Therapeutic Targets Database
DAP000326
PharmGKB
PA448498
Guide to Pharmacology
GtP Drug Page
PDBe Ligand
XB7
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
Wikipedia
Astemizole
PDB Entries
7kxt / 8x5y
MSDS
Download (57.2 KB)

Clinical Trials

Clinical Trials
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PhaseStatusPurposeConditionsCountStart DateWhy Stopped100+ additional columns

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Not Available
Dosage Forms
FormRouteStrength
SuspensionOral0.1 g
TabletOral
TabletOral10.2 mg
TabletOral100 mg
TabletOral0.01 g
SuspensionOral100 mg
Powder, for solutionOral
TabletOral10 mg
TabletOral10 mg / tab
SuspensionOral2 mg / mL
SolutionOral5 mg
SuspensionOral
TabletOral
SolutionOral100 mg
Capsule, coatedOral
Prices
Not Available
Patents
Not Available

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)149.1 °CPhysProp
water solubility432 mg/LNot Available
logP5.8Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.0012 mg/mLALOGPS
logP5.92ALOGPS
logP5.39Chemaxon
logS-5.6ALOGPS
pKa (Strongest Basic)8.73Chemaxon
Physiological Charge1Chemaxon
Hydrogen Acceptor Count4Chemaxon
Hydrogen Donor Count1Chemaxon
Polar Surface Area42.32 Å2Chemaxon
Rotatable Bond Count8Chemaxon
Refractivity135.64 m3·mol-1Chemaxon
Polarizability52.08 Å3Chemaxon
Number of Rings5Chemaxon
Bioavailability1Chemaxon
Rule of FiveNoChemaxon
Ghose FilterNoChemaxon
Veber's RuleNoChemaxon
MDDR-like RuleYesChemaxon
Predicted ADMET Features
PropertyValueProbability
Human Intestinal Absorption+1.0
Blood Brain Barrier+0.765
Caco-2 permeable+0.5217
P-glycoprotein substrateSubstrate0.8162
P-glycoprotein inhibitor IInhibitor0.8563
P-glycoprotein inhibitor IIInhibitor0.8995
Renal organic cation transporterInhibitor0.7708
CYP450 2C9 substrateNon-substrate0.8732
CYP450 2D6 substrateSubstrate0.8918
CYP450 3A4 substrateSubstrate0.6777
CYP450 1A2 substrateInhibitor0.9107
CYP450 2C9 inhibitorNon-inhibitor0.9071
CYP450 2D6 inhibitorInhibitor0.8932
CYP450 2C19 inhibitorInhibitor0.8994
CYP450 3A4 inhibitorNon-inhibitor0.5127
CYP450 inhibitory promiscuityHigh CYP Inhibitory Promiscuity0.9096
Ames testNon AMES toxic0.6444
CarcinogenicityNon-carcinogens0.9553
BiodegradationNot ready biodegradable1.0
Rat acute toxicity2.2847 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Strong inhibitor0.9267
hERG inhibition (predictor II)Inhibitor0.8575
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Not Available
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSsplash10-0a4i-1922000000-2742ecd8a8c6af4db428
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSsplash10-0a4i-0000900000-77d2d1e2fe36c043d63c
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSsplash10-0a4i-0041900000-9f877d4bf52858e41220
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSsplash10-0a4i-0010900000-8af638ce17c135918f44
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSsplash10-0a6r-0222900000-a6bc7d01670a90307570
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSsplash10-092c-1457900000-e2895a845d23ade904e4
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSsplash10-0939-0394400000-a63203113e881f321dbb
Predicted 1H NMR Spectrum1D NMRNot Applicable
Predicted 13C NMR Spectrum1D NMRNot Applicable
Chromatographic Properties
Collision Cross Sections (CCS)
AdductCCS Value (Å2)Source typeSource
[M-H]-236.0935611
predicted
DarkChem Lite v0.1.0
[M-H]-228.1650611
predicted
DarkChem Lite v0.1.0
[M-H]-205.75719
predicted
DeepCCS 1.0 (2019)
[M+H]+234.9121611
predicted
DarkChem Lite v0.1.0
[M+H]+228.4828611
predicted
DarkChem Lite v0.1.0
[M+H]+208.11519
predicted
DeepCCS 1.0 (2019)
[M+Na]+235.1411611
predicted
DarkChem Lite v0.1.0
[M+Na]+228.4488611
predicted
DarkChem Lite v0.1.0
[M+Na]+214.20833
predicted
DeepCCS 1.0 (2019)

Targets

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insights and accelerate drug research.
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Details
1. Histamine H1 receptor
Kind
Protein
Organism
Humans
Pharmacological action
Yes
Actions
Antagonist
General Function
G-protein-coupled receptor for histamine, a biogenic amine that functions as an immune modulator and a neurotransmitter (PubMed:33828102, PubMed:8280179). Through the H1 receptor, histamine mediates the contraction of smooth muscles and increases capillary permeability due to contraction of terminal venules. Also mediates neurotransmission in the central nervous system and thereby regulates circadian rhythms, emotional and locomotor activities as well as cognitive functions (By similarity)
Specific Function
G protein-coupled serotonin receptor activity
Gene Name
HRH1
Uniprot ID
P35367
Uniprot Name
Histamine H1 receptor
Molecular Weight
55783.61 Da
References
  1. Salata JJ, Jurkiewicz NK, Wallace AA, Stupienski RF 3rd, Guinosso PJ Jr, Lynch JJ Jr: Cardiac electrophysiological actions of the histamine H1-receptor antagonists astemizole and terfenadine compared with chlorpheniramine and pyrilamine. Circ Res. 1995 Jan;76(1):110-9. [Article]
  2. Howarth PH, Emanuel MB, Holgate ST: Astemizole, a potent histamine H1-receptor antagonist: effect in allergic rhinoconjunctivitis, on antigen and histamine induced skin weal responses and relationship to serum levels. Br J Clin Pharmacol. 1984 Jul;18(1):1-8. [Article]
  3. Kaliner MA, Check WA: Non-sedating antihistamines. Allergy Proc. 1988 Nov-Dec;9(6):649-63. [Article]
  4. Cavero I, Mestre M, Guillon JM, Heuillet E, Roach AG: Preclinical in vitro cardiac electrophysiology: a method of predicting arrhythmogenic potential of antihistamines in humans? Drug Saf. 1999;21 Suppl 1:19-31; discussion 81-7. [Article]
  5. Llenas J, Cardelus I, Heredia A, de Mora F, Gristwood RW: Cardiotoxicity of histamine and the possible role of histamine in the arrhythmogenesis produced by certain antihistamines. Drug Saf. 1999;21 Suppl 1:33-8; discussion 81-7. [Article]
  6. Richards DM, Brogden RN, Heel RC, Speight TM, Avery GS: Astemizole. A review of its pharmacodynamic properties and therapeutic efficacy. Drugs. 1984 Jul;28(1):38-61. [Article]
  7. Krstenansky PM, Cluxton RJ Jr: Astemizole: a long-acting, nonsedating antihistamine. Drug Intell Clin Pharm. 1987 Dec;21(12):947-53. [Article]
  8. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [Article]
  9. Zhou Y, Zhang Y, Zhao D, Yu X, Shen X, Zhou Y, Wang S, Qiu Y, Chen Y, Zhu F: TTD: Therapeutic Target Database describing target druggability information. Nucleic Acids Res. 2024 Jan 5;52(D1):D1465-D1477. doi: 10.1093/nar/gkad751. [Article]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Pore-forming (alpha) subunit of voltage-gated inwardly rectifying potassium channel (PubMed:10219239, PubMed:10753933, PubMed:10790218, PubMed:10837251, PubMed:11997281, PubMed:12063277, PubMed:18559421, PubMed:22314138, PubMed:22359612, PubMed:26363003, PubMed:27916661, PubMed:9230439, PubMed:9351446, PubMed:9765245). Channel properties are modulated by cAMP and subunit assembly (PubMed:10837251). Characterized by unusual gating kinetics by producing relatively small outward currents during membrane depolarization and large inward currents during subsequent repolarization which reflect a rapid inactivation during depolarization and quick recovery from inactivation but slow deactivation (closing) during repolarization (PubMed:10219239, PubMed:10753933, PubMed:10790218, PubMed:10837251, PubMed:11997281, PubMed:12063277, PubMed:18559421, PubMed:22314138, PubMed:22359612, PubMed:26363003, PubMed:27916661, PubMed:9230439, PubMed:9351446, PubMed:9765245). Channel properties are modulated by cAMP and subunit assembly (PubMed:10837251). Forms a stable complex with KCNE1 or KCNE2, and that this heteromultimerization regulates inward rectifier potassium channel activity (PubMed:10219239, PubMed:9230439)
Specific Function
delayed rectifier potassium channel activity
Gene Name
KCNH2
Uniprot ID
Q12809
Uniprot Name
Voltage-gated inwardly rectifying potassium channel KCNH2
Molecular Weight
126653.52 Da
References
  1. Zhou Z, Vorperian VR, Gong Q, Zhang S, January CT: Block of HERG potassium channels by the antihistamine astemizole and its metabolites desmethylastemizole and norastemizole. J Cardiovasc Electrophysiol. 1999 Jun;10(6):836-43. [Article]
  2. Chachin M, Katayama Y, Yamada M, Horio Y, Ohmura T, Kitagawa H, Uchida S, Kurachi Y: Epinastine, a nonsedating histamine H1 receptor antagonist, has a negligible effect on HERG channel. Eur J Pharmacol. 1999 Jun 25;374(3):457-60. [Article]
  3. Taglialatela M, Castaldo P, Pannaccione A, Giorgio G, Genovese A, Marone G, Annunziato L: Cardiac ion channels and antihistamines: possible mechanisms of cardiotoxicity. Clin Exp Allergy. 1999 Jul;29 Suppl 3:182-9. [Article]
  4. Grzelewska-Rzymowska I, Pietrzkowicz M, Gorska M: [The effect of second generation histamine antagonists on the heart]. Pneumonol Alergol Pol. 2001;69(3-4):217-26. [Article]
  5. Chiu PJ, Marcoe KF, Bounds SE, Lin CH, Feng JJ, Lin A, Cheng FC, Crumb WJ, Mitchell R: Validation of a [3H]astemizole binding assay in HEK293 cells expressing HERG K+ channels. J Pharmacol Sci. 2004 Jul;95(3):311-9. [Article]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
General Function
Pore-forming (alpha) subunit of a voltage-gated delayed rectifier potassium channel that mediates outward-rectifying potassium currents which, on depolarization, reaches a steady-state level and do not inactivate (PubMed:10880439, PubMed:11943152, PubMed:22732247, PubMed:25420144, PubMed:25556795, PubMed:25915598, PubMed:27005320, PubMed:27325704, PubMed:27618660, PubMed:30149017, PubMed:9738473). The activation kinetics depend on the prepulse potential and external divalent cation concentration (PubMed:11943152). With negative prepulses, the current activation is delayed and slowed down several fold, whereas more positive prepulses speed up activation (PubMed:11943152). The time course of activation is biphasic with a fast and a slowly activating current component (PubMed:11943152). Activates at more positive membrane potentials and exhibit a steeper activation curve (PubMed:11943152). Channel properties are modulated by subunit assembly (PubMed:11943152). Mediates IK(NI) current in myoblasts (PubMed:9738473). Involved in the regulation of cell proliferation and differentiation, in particular adipogenic and osteogenic differentiation in bone marrow-derived mesenchymal stem cells (MSCs) (PubMed:23881642)
Specific Function
calmodulin binding
Gene Name
KCNH1
Uniprot ID
O95259
Uniprot Name
Voltage-gated delayed rectifier potassium channel KCNH1
Molecular Weight
111421.76 Da
References
  1. Garcia-Ferreiro RE, Kerschensteiner D, Major F, Monje F, Stuhmer W, Pardo LA: Mechanism of block of hEag1 K+ channels by imipramine and astemizole. J Gen Physiol. 2004 Oct;124(4):301-17. Epub 2004 Sep 13. [Article]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
General Function
Promotes microtubule assembly and stability, and might be involved in the establishment and maintenance of neuronal polarity (PubMed:21985311). The C-terminus binds axonal microtubules while the N-terminus binds neural plasma membrane components, suggesting that tau functions as a linker protein between both (PubMed:21985311, PubMed:32961270). Axonal polarity is predetermined by TAU/MAPT localization (in the neuronal cell) in the domain of the cell body defined by the centrosome. The short isoforms allow plasticity of the cytoskeleton whereas the longer isoforms may preferentially play a role in its stabilization
Specific Function
actin binding
Gene Name
MAPT
Uniprot ID
P10636
Uniprot Name
Microtubule-associated protein tau
Molecular Weight
78927.025 Da
References
  1. Rojo LE, Alzate-Morales J, Saavedra IN, Davies P, Maccioni RB: Selective interaction of lansoprazole and astemizole with tau polymers: potential new clinical use in diagnosis of Alzheimer's disease. J Alzheimers Dis. 2010;19(2):573-89. doi: 10.3233/JAD-2010-1262. [Article]

Enzymes

Details
1. Cytochrome P450 3A4
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
Inhibitor
General Function
A cytochrome P450 monooxygenase involved in the metabolism of sterols, steroid hormones, retinoids and fatty acids (PubMed:10681376, PubMed:11093772, PubMed:11555828, PubMed:12865317, PubMed:14559847, PubMed:15373842, PubMed:15764715, PubMed:19965576, PubMed:20702771, PubMed:21490593, PubMed:21576599). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase). Catalyzes the hydroxylation of carbon-hydrogen bonds (PubMed:12865317, PubMed:14559847, PubMed:15373842, PubMed:15764715, PubMed:21490593, PubMed:21576599, PubMed:2732228). Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1) and 17beta-estradiol (E2), namely 2-hydroxy E1 and E2, as well as D-ring hydroxylated E1 and E2 at the C-16 position (PubMed:11555828, PubMed:12865317, PubMed:14559847). Plays a role in the metabolism of androgens, particularly in oxidative deactivation of testosterone (PubMed:15373842, PubMed:15764715, PubMed:22773874, PubMed:2732228). Metabolizes testosterone to less biologically active 2beta- and 6beta-hydroxytestosterones (PubMed:15373842, PubMed:15764715, PubMed:2732228). Contributes to the formation of hydroxycholesterols (oxysterols), particularly A-ring hydroxylated cholesterol at the C-4beta position, and side chain hydroxylated cholesterol at the C-25 position, likely contributing to cholesterol degradation and bile acid biosynthesis (PubMed:21576599). Catalyzes bisallylic hydroxylation of polyunsaturated fatty acids (PUFA) (PubMed:9435160). Catalyzes the epoxidation of double bonds of PUFA with a preference for the last double bond (PubMed:19965576). Metabolizes endocannabinoid arachidonoylethanolamide (anandamide) to 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:20702771). Plays a role in the metabolism of retinoids. Displays high catalytic activity for oxidation of all-trans-retinol to all-trans-retinal, a rate-limiting step for the biosynthesis of all-trans-retinoic acid (atRA) (PubMed:10681376). Further metabolizes atRA toward 4-hydroxyretinoate and may play a role in hepatic atRA clearance (PubMed:11093772). Responsible for oxidative metabolism of xenobiotics. Acts as a 2-exo-monooxygenase for plant lipid 1,8-cineole (eucalyptol) (PubMed:11159812). Metabolizes the majority of the administered drugs. Catalyzes sulfoxidation of the anthelmintics albendazole and fenbendazole (PubMed:10759686). Hydroxylates antimalarial drug quinine (PubMed:8968357). Acts as a 1,4-cineole 2-exo-monooxygenase (PubMed:11695850). Also involved in vitamin D catabolism and calcium homeostasis. Catalyzes the inactivation of the active hormone calcitriol (1-alpha,25-dihydroxyvitamin D(3)) (PubMed:29461981)
Specific Function
1,8-cineole 2-exo-monooxygenase activity
Gene Name
CYP3A4
Uniprot ID
P08684
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
References
  1. Nicolas JM, Whomsley R, Collart P, Roba J: In vitro inhibition of human liver drug metabolizing enzymes by second generation antihistamines. Chem Biol Interact. 1999 Nov 15;123(1):63-79. [Article]
  2. Matsumoto S, Yamazoe Y: Involvement of multiple human cytochromes P450 in the liver microsomal metabolism of astemizole and a comparison with terfenadine. Br J Clin Pharmacol. 2001 Feb;51(2):133-42. [Article]
  3. Cvetkovic RS, Goa KL: Lopinavir/ritonavir: a review of its use in the management of HIV infection. Drugs. 2003;63(8):769-802. [Article]
  4. Goto A, Adachi Y, Inaba A, Nakajima H, Kobayashi H, Sakai K: Identification of human p450 isoforms involved in the metabolism of the antiallergic drug, oxatomide, and its inhibitory effect on enzyme activity. Biol Pharm Bull. 2004 May;27(5):684-90. [Article]
  5. Goto A, Ueda K, Inaba A, Nakajima H, Kobayashi H, Sakai K: Identification of human P450 isoforms involved in the metabolism of the antiallergic drug, oxatomide, and its kinetic parameters and inhibition constants. Biol Pharm Bull. 2005 Feb;28(2):328-34. [Article]
  6. Zhou S, Yung Chan S, Cher Goh B, Chan E, Duan W, Huang M, McLeod HL: Mechanism-based inhibition of cytochrome P450 3A4 by therapeutic drugs. Clin Pharmacokinet. 2005;44(3):279-304. doi: 10.2165/00003088-200544030-00005. [Article]
  7. Flockhart Table of Drug Interactions [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
A cytochrome P450 monooxygenase involved in the metabolism of steroid hormones and vitamins (PubMed:10681376, PubMed:11093772, PubMed:12865317, PubMed:2732228). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase). Catalyzes the hydroxylation of carbon-hydrogen bonds (PubMed:10681376, PubMed:11093772, PubMed:12865317, PubMed:2732228). Exhibits high catalytic activity for the formation of catechol estrogens from 17beta-estradiol (E2) and estrone (E1), namely 2-hydroxy E1 and E2 (PubMed:12865317). Catalyzes 6beta-hydroxylation of the steroid hormones testosterone, progesterone, and androstenedione (PubMed:2732228). Catalyzes the oxidative conversion of all-trans-retinol to all-trans-retinal, a rate-limiting step for the biosynthesis of all-trans-retinoic acid (atRA) (PubMed:10681376). Further metabolizes all trans-retinoic acid (atRA) to 4-hydroxyretinoate and may play a role in hepatic atRA clearance (PubMed:11093772). Also involved in the oxidative metabolism of xenobiotics, including calcium channel blocking drug nifedipine and immunosuppressive drug cyclosporine (PubMed:2732228)
Specific Function
aromatase activity
Gene Name
CYP3A5
Uniprot ID
P20815
Uniprot Name
Cytochrome P450 3A5
Molecular Weight
57108.065 Da
References
  1. Flockhart Table of Drug Interactions [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
A cytochrome P450 monooxygenase involved in the metabolism of steroid hormones and vitamins during embryogenesis (PubMed:11093772, PubMed:12865317, PubMed:14559847, PubMed:17178770, PubMed:9555064). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:11093772, PubMed:12865317, PubMed:14559847, PubMed:17178770, PubMed:9555064). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes 3beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone, DHEA), a precursor in the biosynthesis of androgen and estrogen steroid hormones (PubMed:17178770, PubMed:9555064). Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1), particularly D-ring hydroxylated estrone at the C16-alpha position (PubMed:12865317, PubMed:14559847). Mainly hydroxylates all trans-retinoic acid (atRA) to 4-hydroxyretinoate and may play a role in atRA clearance during fetal development (PubMed:11093772). Also involved in the oxidative metabolism of xenobiotics including anticonvulsants (PubMed:9555064)
Specific Function
all-trans retinoic acid 18-hydroxylase activity
Gene Name
CYP3A7
Uniprot ID
P24462
Uniprot Name
Cytochrome P450 3A7
Molecular Weight
57469.95 Da
References
  1. Flockhart Table of Drug Interactions [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
A cytochrome P450 monooxygenase involved in the metabolism of fatty acids, steroids and retinoids (PubMed:18698000, PubMed:19965576, PubMed:20972997, PubMed:21289075, PubMed:21576599). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:18698000, PubMed:19965576, PubMed:20972997, PubMed:21289075, PubMed:21576599). Catalyzes the epoxidation of double bonds of polyunsaturated fatty acids (PUFA) (PubMed:19965576, PubMed:20972997). Metabolizes endocannabinoid arachidonoylethanolamide (anandamide) to 20-hydroxyeicosatetraenoic acid ethanolamide (20-HETE-EA) and 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:18698000, PubMed:21289075). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes cholesterol toward 25-hydroxycholesterol, a physiological regulator of cellular cholesterol homeostasis (PubMed:21576599). Catalyzes the oxidative transformations of all-trans retinol to all-trans retinal, a precursor for the active form all-trans-retinoic acid (PubMed:10681376). Also involved in the oxidative metabolism of drugs such as antiarrhythmics, adrenoceptor antagonists, and tricyclic antidepressants
Specific Function
anandamide 11,12 epoxidase activity
Gene Name
CYP2D6
Uniprot ID
P10635
Uniprot Name
Cytochrome P450 2D6
Molecular Weight
55768.94 Da
References
  1. Matsumoto S, Yamazoe Y: Involvement of multiple human cytochromes P450 in the liver microsomal metabolism of astemizole and a comparison with terfenadine. Br J Clin Pharmacol. 2001 Feb;51(2):133-42. [Article]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
A cytochrome P450 monooxygenase involved in the metabolism of polyunsaturated fatty acids (PUFA) in the cardiovascular system (PubMed:19965576, PubMed:8631948). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:19965576, PubMed:8631948). Catalyzes the epoxidation of double bonds of PUFA (PubMed:19965576, PubMed:8631948). Converts arachidonic acid to four regioisomeric epoxyeicosatrienoic acids (EpETrE), likely playing a major role in the epoxidation of endogenous cardiac arachidonic acid pools (PubMed:8631948). In endothelial cells, participates in eicosanoids metabolism by converting hydroperoxide species into hydroxy epoxy metabolites. In combination with 15-lipoxygenase metabolizes arachidonic acid and converts hydroperoxyicosatetraenoates (HpETEs) into hydroxy epoxy eicosatrienoates (HEETs), which are precursors of vasodilatory trihydroxyicosatrienoic acids (THETAs). This hydroperoxide isomerase activity is NADPH- and O2-independent (PubMed:19737933). Catalyzes the monooxygenation of a various xenobiotics, such as danazol, amiodarone, terfenadine, astemizole, thioridazine, tamoxifen, cyclosporin A and nabumetone (PubMed:19923256). Catalyzes hydroxylation of the anthelmintics albendazole and fenbendazole (PubMed:23959307). Catalyzes the sulfoxidation of fenbedazole (PubMed:19923256)
Specific Function
arachidonic acid 11,12-epoxygenase activity
Gene Name
CYP2J2
Uniprot ID
P51589
Uniprot Name
Cytochrome P450 2J2
Molecular Weight
57610.165 Da
References
  1. Matsumoto S, Hirama T, Matsubara T, Nagata K, Yamazoe Y: Involvement of CYP2J2 on the intestinal first-pass metabolism of antihistamine drug, astemizole. Drug Metab Dispos. 2002 Nov;30(11):1240-5. [Article]
  2. Lee SS, Jeong HE, Liu KH, Ryu JY, Moon T, Yoon CN, Oh SJ, Yun CH, Shin JG: Identification and functional characterization of novel CYP2J2 variants: G312R variant causes loss of enzyme catalytic activity. Pharmacogenet Genomics. 2005 Feb;15(2):105-13. [Article]
  3. Matsumoto S, Hirama T, Kim HJ, Nagata K, Yamazoe Y: In vitro inhibition of human small intestinal and liver microsomal astemizole O-demethylation: different contribution of CYP2J2 in the small intestine and liver. Xenobiotica. 2003 Jun;33(6):615-23. doi: 10.1080/0049825031000105778 . [Article]

Transporters

Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Translocates drugs and phospholipids across the membrane (PubMed:2897240, PubMed:35970996, PubMed:8898203, PubMed:9038218). Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins (PubMed:8898203). Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells (PubMed:2897240, PubMed:35970996, PubMed:9038218)
Specific Function
ABC-type xenobiotic transporter activity
Gene Name
ABCB1
Uniprot ID
P08183
Uniprot Name
ATP-dependent translocase ABCB1
Molecular Weight
141477.255 Da
References
  1. Schwab D, Fischer H, Tabatabaei A, Poli S, Huwyler J: Comparison of in vitro P-glycoprotein screening assays: recommendations for their use in drug discovery. J Med Chem. 2003 Apr 24;46(9):1716-25. [Article]
  2. Ishikawa M, Fujita R, Takayanagi M, Takayanagi Y, Sasaki K: Reversal of acquired resistance to doxorubicin in K562 human leukemia cells by astemizole. Biol Pharm Bull. 2000 Jan;23(1):112-5. [Article]
Kind
Protein
Organism
Humans
Pharmacological action
No
Actions
Substrate
General Function
Catalyzes the transport of the major hydrophobic bile salts, such as taurine and glycine-conjugated cholic acid across the canalicular membrane of hepatocytes in an ATP-dependent manner, therefore participates in hepatic bile acid homeostasis and consequently to lipid homeostasis through regulation of biliary lipid secretion in a bile salts dependent manner (PubMed:15791618, PubMed:16332456, PubMed:18985798, PubMed:19228692, PubMed:20010382, PubMed:20398791, PubMed:22262466, PubMed:24711118, PubMed:29507376, PubMed:32203132). Transports taurine-conjugated bile salts more rapidly than glycine-conjugated bile salts (PubMed:16332456). Also transports non-bile acid compounds, such as pravastatin and fexofenadine in an ATP-dependent manner and may be involved in their biliary excretion (PubMed:15901796, PubMed:18245269)
Specific Function
ABC-type bile acid transporter activity
Gene Name
ABCB11
Uniprot ID
O95342
Uniprot Name
Bile salt export pump
Molecular Weight
146405.83 Da
References
  1. Pedersen JM, Matsson P, Bergstrom CA, Hoogstraate J, Noren A, LeCluyse EL, Artursson P: Early identification of clinically relevant drug interactions with the human bile salt export pump (BSEP/ABCB11). Toxicol Sci. 2013 Dec;136(2):328-43. doi: 10.1093/toxsci/kft197. Epub 2013 Sep 6. [Article]

Drug created at June 13, 2005 13:24 / Updated at October 21, 2024 12:37