Record Information
Version1.0
Creation Date2009-07-21 20:27:29 UTC
Update Date2026-05-14 16:46:54 UTC
Accession NumberCHEM002256
Identification
Common NameParoxetine
ClassSmall Molecule
DescriptionParoxetine hydrochloride and paroxetine mesylate belong to a class of antidepressant agents known as selective serotonin-reuptake inhibitors (SSRIs). Despite distinct structural differences between compounds in this class, SSRIs possess similar pharmacological activity. As with other antidepressant agents, several weeks of therapy may be required before a clinical effect is seen. SSRIs are potent inhibitors of neuronal serotonin reuptake. They have little to no effect on norepinephrine or dopamine reuptake and do not antagonize α- or β-adrenergic, dopamine D2 or histamine H1 receptors. During acute use, SSRIs block serotonin reuptake and increase serotonin stimulation of somatodendritic 5-HT1A and terminal autoreceptors. Chronic use leads to desensitization of somatodendritic 5-HT1A and terminal autoreceptors. The overall clinical effect of increased mood and decreased anxiety is thought to be due to adaptive changes in neuronal function that leads to enhanced serotonergic neurotransmission. Side effects include dry mouth, nausea, dizziness, drowsiness, sexual dysfunction and headache (see Toxicity section below for a complete listing of side effects). Side effects generally occur during the first two weeks of therapy and are usually less severe and frequent than those observed with tricyclic antidepressants. Paroxetine hydrochloride and mesylate are considered therapeutic alternatives rather than generic equivalents by the US Food and Drug Administration (FDA); both agents contain the same active moiety (i.e. paroxetine), but are formulated as different salt forms. Clinical studies establishing the efficacy of paroxetine in various conditions were performed using paroxetine hydrochloride. Since both agents contain the same active moiety, the clinical efficacy of both agents is thought to be similar. Paroxetine may be used to treat major depressive disorder (MDD), panic disorder with or without agoraphobia, obsessive-compulsive disorder (OCD), social anxiety disorder (social phobia), generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD) and premenstrual dysphoric disorder (PMDD). Paroxetine has the most evidence supporting its use for anxiety-related disorders of the SSRIs. It has the greatest anticholinergic activity of the agents in this class and compared to other SSRIs, paroxetine may cause greater weight gain, sexual dysfunction, sedation and constipation.
Contaminant Sources
  • HMDB Contaminants - Urine
  • STOFF IDENT Compounds
  • Suspected Compounds
  • T3DB toxins
  • ToxCast & Tox21 Chemicals
Contaminant Type
  • Amine
  • Antidepressant
  • Antidepressant, Second-Generation
  • Antidepressive Agent
  • Drug
  • Ether
  • Food Toxin
  • Metabolite
  • Organic Compound
  • Organofluoride
  • Selective Serotonin Reuptake Inhibitor
  • Serotonin Uptake Inhibitor
  • Synthetic Compound
Chemical Structure
Thumb
Synonyms
ValueSource
(-)-(3S,4R)-4-(p-Fluorophenyl)-3-((3,4-(methylenedioxy)phenoxy)methyl)piperidineChEBI
(3S-trans)-3-((1,3-Benzodioxol-5-yloxy)methyl)-4-(4-fluorophenyl)piperidineChEBI
ParoxetinaChEBI
ParoxetinumChEBI
Hydrochloride hemihydrate, paroxetineHMDB
Hydrochloride, hemihydrate paroxetineHMDB
Acetate, paroxetineHMDB
Maleate, paroxetineHMDB
Paroxetine acetateHMDB
Paroxetine hydrochloride hemihydrateHMDB
Paroxetine, trans-(+)-isomerHMDB
SeroxatHMDB
AropaxHMDB
Hemihydrate paroxetine hydrochlorideHMDB
Paroxetine hydrochloride anhydrousHMDB
Paroxetine, cis-(+)-isomerHMDB
PaxilHMDB
Anhydrous, paroxetine hydrochlorideHMDB
Hemihydrate, paroxetine hydrochlorideHMDB
Hydrochloride anhydrous, paroxetineHMDB
Hydrochloride, paroxetineHMDB
Paroxetine hydrochlorideHMDB
Paroxetine hydrochloride, hemihydrateHMDB
Paroxetine maleateHMDB
Paroxetine, cis-(-)-isomerHMDB
Chemical FormulaC19H20FNO3
Average Molecular Mass329.365 g/mol
Monoisotopic Mass329.143 g/mol
CAS Registry Number61869-08-7
IUPAC Name(3S,4R)-3-[(2H-1,3-benzodioxol-5-yloxy)methyl]-4-(4-fluorophenyl)piperidine
Traditional Nameparoxetine
SMILESFC1=CC=C(C=C1)[C@@H]1CCNC[C@H]1COC1=CC2=C(OCO2)C=C1
InChI IdentifierInChI=1S/C19H20FNO3/c20-15-3-1-13(2-4-15)17-7-8-21-10-14(17)11-22-16-5-6-18-19(9-16)24-12-23-18/h1-6,9,14,17,21H,7-8,10-12H2/t14-,17-/m0/s1
InChI KeyAHOUBRCZNHFOSL-YOEHRIQHSA-N
Chemical Taxonomy
Description belongs to the class of organic compounds known as phenylpiperidines. Phenylpiperidines are compounds containing a phenylpiperidine skeleton, which consists of a piperidine bound to a phenyl group.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassPiperidines
Sub ClassPhenylpiperidines
Direct ParentPhenylpiperidines
Alternative Parents
Substituents
  • Phenylpiperidine
  • Benzodioxole
  • Alkyl aryl ether
  • Fluorobenzene
  • Halobenzene
  • Aralkylamine
  • Aryl fluoride
  • Aryl halide
  • Monocyclic benzene moiety
  • Benzenoid
  • Ether
  • Secondary aliphatic amine
  • Acetal
  • Oxacycle
  • Secondary amine
  • Azacycle
  • Organooxygen compound
  • Organonitrogen compound
  • Organofluoride
  • Organohalogen compound
  • Hydrocarbon derivative
  • Organopnictogen compound
  • Organic oxygen compound
  • Amine
  • Organic nitrogen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Membrane
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
Applications
Biological Roles
Chemical Roles
Physical Properties
StateSolid
AppearanceWhite powder.
Experimental Properties
PropertyValue
Melting Point147-150°C (mesylate salt)
Boiling PointNot Available
Solubility>1 g/mL (mesylate salt)
Predicted Properties
PropertyValueSource
Water Solubility0.0085 g/LALOGPS
logP3.1ALOGPS
logP3.15ChemAxon
logS-4.6ALOGPS
pKa (Strongest Basic)9.77ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area39.72 ŲChemAxon
Rotatable Bond Count4ChemAxon
Refractivity88.02 m³·mol⁻¹ChemAxon
Polarizability34.48 ųChemAxon
Number of Rings4ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-0f9i-1911000000-12c3e68d4fb152fcf19aSpectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, PositiveNot AvailableSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-001i-3709000000-7d029049c2e6d638ecbeSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-001i-2409000000-077fb077fbf0e4210f51Spectrum
LC-MS/MSLC-MS/MS Spectrum - 10V, Positivesplash10-001i-0009000000-56cd88a7bae65159b40eSpectrum
LC-MS/MSLC-MS/MS Spectrum - 40V, Positivesplash10-00di-9300000000-95d57654f38599951250Spectrum
LC-MS/MSLC-MS/MS Spectrum - -1V, Positivesplash10-001i-3609000000-814e80528f9dde6c33a5Spectrum
LC-MS/MSLC-MS/MS Spectrum - 20V, Positivesplash10-001l-6809000000-6461647e2077c359be2eSpectrum
LC-MS/MSLC-MS/MS Spectrum - 35V, Positivesplash10-001l-2906000000-a8c78adc02d4f098ec53Spectrum
LC-MS/MSLC-MS/MS Spectrum - 35V, Positivesplash10-001i-2309000000-dae2fa8b8f5f0d2d9c83Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-001i-0409000000-034c664e49ac69cc6701Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0uel-1915000000-1cceed9b83dba502dc39Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0006-6900000000-a45d96d1002ba6a0049eSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-004i-0409000000-7b0c408204b05629f155Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-002r-1829000000-c76de0eff9bcad218ff4Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-000i-4900000000-77810e81d9b6e4cb0cf7Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-001i-0409000000-52ccb63e39824262697aSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-001r-0915000000-6663900bf83beabe3f50Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-004r-0901000000-7e65658f2aa91b98e293Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-000i-0903000000-8712cfe4d48fe9ccd484Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-004r-0927000000-031f43eecdb967cf56aeSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4i-1900000000-6adcbe9a9b2a0603a1ceSpectrum
MSMass Spectrum (Electron Ionization)splash10-0006-8900000000-0a273deac3c7836cdc76Spectrum
Toxicity Profile
Route of ExposureParoxetine hydrochloride is slowly, but completely absorbed following oral administration. Paroxetine mesylate salt is also completely absorbed after oral dosing. The oral bioavailability appears to be low due to extensive first-pass metabolism. Paroxetine hydrochloride oral tablets and suspension are reportedly bioequivalent. Absorption of either salt form is not substantially affected by food. Peak concentrations of Brisbelle (mesylate salt) were reached at 6 hours (3 to 8 hours range). Steady state Cmax was 13.10 ng/mL. The steady state AUC (0-last) was 237 hr*ng/mL. Paroxetine mesylate generally follows non-linear pharmacokinetics because CYP2D6, the enzyme that is part responisible for paroxetine metabolism, is readily saturable.
Mechanism of ToxicityParoxetine is a potent and highly selective inhibitor of neuronal serotonin reuptake. Paroxetine likely inhibits the reuptake of serotonin at the neuronal membrane, enhances serotonergic neurotransmission by reducing turnover of the neurotransmitter, therefore it prolongs its activity at synaptic receptor sites and potentiates 5-HT in the CNS; paroxetine is more potent than both sertraline and fluoxetine in its ability to inhibit 5-HT reuptake. Compared to the tricyclic antidepressants, SSRIs have dramatically decreased binding to histamine, acetylcholine, and norepinephrine receptors. The mechanism of action for the treatment of vasomotor symptoms is unknown.
MetabolismParoxetine is extensively metabolized after oral administration, likely in the liver. The main metabolites are polar and conjugated products of oxidation and methylation, which are readily eliminated by the body. The predominant metabolites are glucuronic acid and sulfate conjugates. Paroxetine metabolites do not possess significant pharmacologic activity (less than 2% that of parent compound). Paroxetine is metabolized by cytochrome P450 (CYP) 2D6. Enzyme saturation appears to account for the nonlinear pharmacokinetics observed with increasing dose and duration of therapy. Route of Elimination: Approximately 64% of a 30 mg oral solution of paroxetine was excreted in the urine with 2% as the parent compound and 62% as metabolites. Approximately 36% of the dose was excreted in the feces (via bile), mostly as metabolites and less than 1% as parent compound. Half Life: 21-24 hours
Toxicity ValuesLD50: 500mg/kg (Oral, Mouse) (1)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesLabeled indications include: major depressive disorder (MDD), panic disorder with or without agoraphobia, obsessive-compulsive disorder (OCD), social anxiety disorder (social phobia), generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD), and premenstrual dysphoric disorder (PMDD). Unlabeled indications include: eating disorders, impulse control disorders, vasomotor symptoms of menopause, obsessive-compulsive disorder (OCD) in children, and mild dementia-associated agitation in nonpsychotic individuals. Brisdelle, which consists of paroxetine mesylate is indicated for the treatment of moderate to severe vasomotor symptoms (like hot flashes) associated with menopause.
Minimum Risk LevelNot Available
Health EffectsNot Available
SymptomsComa, dizziness, drowsiness, facial flushing, nausea, sweating, tremor, vomiting
TreatmentTreatment should consist of those general measures employed in the management of overdosage with any drugs effective in the treatment of major depressive disorder. Ensure an adequate airway, oxygenation, and ventilation. Monitor cardiac rhythm and vital signs. General supportive and symptomatic measures are also recommended. Induction of emesis is not recommended. Gastric lavage with a large-bore orogastric tube with appropriate airway protection, if needed, may be indicated if performed soon after ingestion, or in symptomatic patients. Activated charcoal should be administered. Due to the large volume of distribution of this drug, forced diuresis, dialysis, hemoperfusion, and exchange transfusion are unlikely to be of benefit. No specific antidotes for paroxetine are known. (8)
Concentrations
Not Available
DrugBank IDDB00715
HMDB IDHMDB0014853
FooDB IDNot Available
Phenol Explorer IDNot Available
KNApSAcK IDNot Available
BiGG IDNot Available
BioCyc IDNot Available
METLIN IDNot Available
PDB IDNot Available
Wikipedia LinkParoxetine
Chemspider ID39888
ChEBI ID7936
PubChem Compound ID43815
Kegg Compound IDC07415
YMDB IDNot Available
ECMDB IDNot Available
References
Synthesis Reference

Charles M. Zepp, Yun Gao, Donald L. Heefner, “Method of preparing optically pure precursors of paroxetine.” U.S. Patent US5258517, issued January, 1976.

MSDSLink
General References
1. Yonkers KA, Gullion C, Williams A, Novak K, Rush AJ: Paroxetine as a treatment for premenstrual dysphoric disorder. J Clin Psychopharmacol. 1996 Feb;16(1):3-8.
2. Waldinger MD, Hengeveld MW, Zwinderman AH, Olivier B: Effect of SSRI antidepressants on ejaculation: a double-blind, randomized, placebo-controlled study with fluoxetine, fluvoxamine, paroxetine, and sertraline. J Clin Psychopharmacol. 1998 Aug;18(4):274-81.
3. Baldwin D, Bobes J, Stein DJ, Scharwachter I, Faure M: Paroxetine in social phobia/social anxiety disorder. Randomised, double-blind, placebo-controlled study. Paroxetine Study Group. Br J Psychiatry. 1999 Aug;175:120-6.
4. Waldinger MD, Zwinderman AH, Olivier B: SSRIs and ejaculation: a double-blind, randomized, fixed-dose study with paroxetine and citalopram. J Clin Psychopharmacol. 2001 Dec;21(6):556-60.
5. Baldwin DS, Anderson IM, Nutt DJ, Bandelow B, Bond A, Davidson JR, den Boer JA, Fineberg NA, Knapp M, Scott J, Wittchen HU: Evidence-based guidelines for the pharmacological treatment of anxiety disorders: recommendations from the British Association for Psychopharmacology. J Psychopharmacol. 2005 Nov;19(6):567-96.
6. https://www.ncbi.nlm.nih.gov/pubmed/?term=11009210
7. https://www.ncbi.nlm.nih.gov/pubmed/?term=11169163
8. https://www.ncbi.nlm.nih.gov/pubmed/?term=11271409
9. https://www.ncbi.nlm.nih.gov/pubmed/?term=11281965
10. https://www.ncbi.nlm.nih.gov/pubmed/?term=11324355
11. https://www.ncbi.nlm.nih.gov/pubmed/?term=11360029
12. https://www.ncbi.nlm.nih.gov/pubmed/?term=11513198
13. https://www.ncbi.nlm.nih.gov/pubmed/?term=11563413
14. https://www.ncbi.nlm.nih.gov/pubmed/?term=11565622
15. https://www.ncbi.nlm.nih.gov/pubmed/?term=11819027
16. https://www.ncbi.nlm.nih.gov/pubmed/?term=11893234
17. https://www.ncbi.nlm.nih.gov/pubmed/?term=11910269
18. https://www.ncbi.nlm.nih.gov/pubmed/?term=12027788
19. https://www.ncbi.nlm.nih.gov/pubmed/?term=12088162
20. https://www.ncbi.nlm.nih.gov/pubmed/?term=12369443
21. https://www.ncbi.nlm.nih.gov/pubmed/?term=12421645
22. https://www.ncbi.nlm.nih.gov/pubmed/?term=12818234
23. https://www.ncbi.nlm.nih.gov/pubmed/?term=12820211
24. https://www.ncbi.nlm.nih.gov/pubmed/?term=12906023
25. https://www.ncbi.nlm.nih.gov/pubmed/?term=12920419
26. https://www.ncbi.nlm.nih.gov/pubmed/?term=14516531
27. https://www.ncbi.nlm.nih.gov/pubmed/?term=14521492
28. https://www.ncbi.nlm.nih.gov/pubmed/?term=14566196
29. https://www.ncbi.nlm.nih.gov/pubmed/?term=14566200
30. https://www.ncbi.nlm.nih.gov/pubmed/?term=14619895
31. https://www.ncbi.nlm.nih.gov/pubmed/?term=14624192
32. https://www.ncbi.nlm.nih.gov/pubmed/?term=14673053
33. https://www.ncbi.nlm.nih.gov/pubmed/?term=14689334
34. https://www.ncbi.nlm.nih.gov/pubmed/?term=14978354
35. https://www.ncbi.nlm.nih.gov/pubmed/?term=15048901
36. https://www.ncbi.nlm.nih.gov/pubmed/?term=15199661
37. https://www.ncbi.nlm.nih.gov/pubmed/?term=15241233
38. https://www.ncbi.nlm.nih.gov/pubmed/?term=15264994
39. https://www.ncbi.nlm.nih.gov/pubmed/?term=15374134
40. https://www.ncbi.nlm.nih.gov/pubmed/?term=15376524
41. https://www.ncbi.nlm.nih.gov/pubmed/?term=15544025
42. https://www.ncbi.nlm.nih.gov/pubmed/?term=15613191
43. https://www.ncbi.nlm.nih.gov/pubmed/?term=15845695
44. https://www.ncbi.nlm.nih.gov/pubmed/?term=15853570
45. https://www.ncbi.nlm.nih.gov/pubmed/?term=15903129
46. https://www.ncbi.nlm.nih.gov/pubmed/?term=15963219
47. https://www.ncbi.nlm.nih.gov/pubmed/?term=15992089
48. https://www.ncbi.nlm.nih.gov/pubmed/?term=16395417
49. https://www.ncbi.nlm.nih.gov/pubmed/?term=16397315
50. https://www.ncbi.nlm.nih.gov/pubmed/?term=16426087
51. https://www.ncbi.nlm.nih.gov/pubmed/?term=16765127
52. https://www.ncbi.nlm.nih.gov/pubmed/?term=16822276
53. https://www.ncbi.nlm.nih.gov/pubmed/?term=16913391
54. https://www.ncbi.nlm.nih.gov/pubmed/?term=17122538
55. https://www.ncbi.nlm.nih.gov/pubmed/?term=17162096
56. https://www.ncbi.nlm.nih.gov/pubmed/?term=17219219
57. https://www.ncbi.nlm.nih.gov/pubmed/?term=17286545
58. https://www.ncbi.nlm.nih.gov/pubmed/?term=17452166
59. https://www.ncbi.nlm.nih.gov/pubmed/?term=17559097
60. https://www.ncbi.nlm.nih.gov/pubmed/?term=17612590
61. https://www.ncbi.nlm.nih.gov/pubmed/?term=17652957
62. https://www.ncbi.nlm.nih.gov/pubmed/?term=17874333
63. https://www.ncbi.nlm.nih.gov/pubmed/?term=18273418
64. https://www.ncbi.nlm.nih.gov/pubmed/?term=18345955
65. https://www.ncbi.nlm.nih.gov/pubmed/?term=18808757
66. https://www.ncbi.nlm.nih.gov/pubmed/?term=18983224
67. https://www.ncbi.nlm.nih.gov/pubmed/?term=19687003
68. https://www.ncbi.nlm.nih.gov/pubmed/?term=19851065
69. https://www.ncbi.nlm.nih.gov/pubmed/?term=21404089
70. https://www.ncbi.nlm.nih.gov/pubmed/?term=21452176
71. https://www.ncbi.nlm.nih.gov/pubmed/?term=21739267
72. https://www.ncbi.nlm.nih.gov/pubmed/?term=21908494
73. https://www.ncbi.nlm.nih.gov/pubmed/?term=21909633
74. https://www.ncbi.nlm.nih.gov/pubmed/?term=21922171
75. https://www.ncbi.nlm.nih.gov/pubmed/?term=21939725
76. https://www.ncbi.nlm.nih.gov/pubmed/?term=22153922
77. https://www.ncbi.nlm.nih.gov/pubmed/?term=22198456
78. https://www.ncbi.nlm.nih.gov/pubmed/?term=22212003
79. https://www.ncbi.nlm.nih.gov/pubmed/?term=22240860
80. https://www.ncbi.nlm.nih.gov/pubmed/?term=22263916
81. https://www.ncbi.nlm.nih.gov/pubmed/?term=22283559
82. https://www.ncbi.nlm.nih.gov/pubmed/?term=22353759
83. https://www.ncbi.nlm.nih.gov/pubmed/?term=22377745