1. 2-benzofurancarboxamide, 5-(4-(4-(5-cyano-1h-indol-3-yl)butyl)-1-piperazinyl)-, Hydrochloride (1:1)
2. 5-(4-(4-(5-cyano-3-indolyl)butyl)-1-piperazinyl)benzofuran-2-carboxamide
3. 68843, Emd
4. Emb 68843
5. Emb-68843
6. Emb68843
7. Emd 68843
8. Hcl, Vilazodone
9. Hydrochloride, Vilazodone
10. Viibryd
11. Vilazodone Hcl
12. Vilazodone Hydrochloride
1. 163521-12-8
2. 5-(4-(4-(5-cyano-1h-indol-3-yl)butyl)piperazin-1-yl)benzofuran-2-carboxamide
3. Emd 515259
4. Emd-515259
5. Emd-68-843
6. 5-[4-[4-(5-cyano-1h-indol-3-yl)butyl]piperazin-1-yl]-1-benzofuran-2-carboxamide
7. 5-{4-[4-(5-cyano-1h-indol-3-yl)butyl]piperazin-1-yl}-1-benzofuran-2-carboxamide
8. Chembl439849
9. S239o2oov3
10. Chebi:70707
11. Vilazodone [inn]
12. Emd 68843 (hydrochloride);sb659746a (hydrochloride)
13. 5-(4-(4-(5-cyanoindol-3-yl)butyl)-1-piperazinyl)-2-benzofurancarboxamide
14. 2-benzofurancarboxamide, 5-[4-[4-(5-cyano-1h-indol-3-yl)butyl]-1-piperazinyl]-
15. Vilazodone [usan:inn]
16. Vilazodona
17. Vilazodonum
18. Unii-s239o2oov3
19. Hsdb 8197
20. 2-benzofurancarboxamide, 5-(4-(4-(5-cyano-1h-indol-3-yl)butyl)-1-piperazinyl)-
21. 5-(4-[4-(5-cyano-1h-indol-3-yl)butyl]piperazin-1-yl)benzofuran-2-carboxamide
22. Vilazodone [mi]
23. Vilazodone (usan/inn)
24. Vilazodone [usan]
25. Vilazodone [vandf]
26. Vilazodone [mart.]
27. Vilazodone [who-dd]
28. Schembl650682
29. Gtpl7427
30. Yl}-1-benzofuran-2-carboxamide
31. Dtxsid80870086
32. Ex-a174
33. Hms3744c03
34. Hms3886n05
35. Amy22748
36. Bcp05225
37. Zinc1542113
38. Bdbm50151982
39. Mfcd09838919
40. S5858
41. 1-[4-(5-cyanoindol-3-yl)butyl]-4-(2-carbamoylbenzofuran-5-yl)piperazine
42. Akos015924744
43. Cs-0550
44. Db06684
45. Pb25213
46. Sb20296
47. Ncgc00371130-03
48. Ncgc00371130-06
49. Ac-25886
50. As-73542
51. Hy-14262
52. Emd 68843;sb 659746a
53. Ft-0675813
54. D09698
55. Ab01563299_01
56. A900227
57. L001518
58. Q408588
59. 5-{4-[4-(5-cyano-1h-indol-3-yl)butyl]piperazin-1-
60. F0001-2418
61. 1-[4-(5-cyanoindol-3-yl)butyl]4-(2-carbamoyl-benzofuran-5-yl)-piperazine
62. 5-{4-[4-(5-cyano-3-indolyl)butyl]-1-piperazinyl}benzo-furan-2-carboxamide
63. 1-[4-(5-cyanoindol-3-yl)butyl]-4-(2-carbamoyl-benzofuran-5-yl)-piperazine
64. 5 -(4-(4-(5 -cyano-1h-indol-3 -yl)butyl)piperazin-1 -yl)benzofuran-2-carboxamide
65. 5-[4-[4-(5-cyanoindol-3-yl)butyl]piperazin-1-yl]benzofuran-2-carboxamide
66. 5-{4-[4-(5-cyano-1h-indol-3-yl)-butyl]-piperazin-1-yl}-benzofuran-2-carboxylic Acid Amide
| Molecular Weight | 441.5 g/mol |
|---|---|
| Molecular Formula | C26H27N5O2 |
| XLogP3 | 4 |
| Hydrogen Bond Donor Count | 2 |
| Hydrogen Bond Acceptor Count | 5 |
| Rotatable Bond Count | 7 |
| Exact Mass | 441.21647512 g/mol |
| Monoisotopic Mass | 441.21647512 g/mol |
| Topological Polar Surface Area | 102 Ų |
| Heavy Atom Count | 33 |
| Formal Charge | 0 |
| Complexity | 729 |
| Isotope Atom Count | 0 |
| Defined Atom Stereocenter Count | 0 |
| Undefined Atom Stereocenter Count | 0 |
| Defined Bond Stereocenter Count | 0 |
| Undefined Bond Stereocenter Count | 0 |
| Covalently Bonded Unit Count | 1 |
| 1 of 2 | |
|---|---|
| Drug Name | Viibryd |
| PubMed Health | Vilazodone (By mouth) |
| Drug Classes | Antidepressant |
| Drug Label | VIIBRYD Tablets for oral administration contain polymorph Form IV vilazodone hydrochloride (HCl), a selective serotonin reuptake inhibitor and a 5HT1A receptor partial agonist.Vilazodone HCl is 2-benzofurancarboxamide, 5-[4-[4-(5-cyano-1H-indol-3-yl)... |
| Active Ingredient | Vilazodone hydrochloride |
| Dosage Form | Tablet |
| Route | Oral |
| Strength | 10mg; 40mg; 20mg |
| Market Status | Prescription |
| Company | Forest Labs |
| 2 of 2 | |
|---|---|
| Drug Name | Viibryd |
| PubMed Health | Vilazodone (By mouth) |
| Drug Classes | Antidepressant |
| Drug Label | VIIBRYD Tablets for oral administration contain polymorph Form IV vilazodone hydrochloride (HCl), a selective serotonin reuptake inhibitor and a 5HT1A receptor partial agonist.Vilazodone HCl is 2-benzofurancarboxamide, 5-[4-[4-(5-cyano-1H-indol-3-yl)... |
| Active Ingredient | Vilazodone hydrochloride |
| Dosage Form | Tablet |
| Route | Oral |
| Strength | 10mg; 40mg; 20mg |
| Market Status | Prescription |
| Company | Forest Labs |
Antidepressant
National Library of Medicine, SIS; ChemIDplus Lite Record for Vilazodone (163521-12-8). Available from, as of May 30, 2014: https://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp
Viibryd is indicated for the treatment of major depressive disorder (MDD). The efficacy of Viibryd was established in two 8-week, randomized, double-blind, placebo-controlled trials in adult patients with a diagnosis of MDD. Major depressive disorder consists of one or more major depressive episodes. A major depressive episode (DSM-IV-TR) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed or dysphoric mood that usually interferes with daily functioning, and includes at least 5 of the following 9 symptoms: depressed mood, loss of interest in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, or a suicide attempt or suicidal ideation. /Included in US product label/
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
EXPL THER Sexual dysfunction is common in major depressive disorder (MDD), and many serotonergic antidepressants adversely affect sexual function. Vilazodone, a novel serotonin (5-HT) reuptake inhibitor and 5-HT1A partial agonist approved for MDD, exerts its effects at the 5-HT transporter and at both presynaptic and postsynaptic 5-HT1A receptors. This mechanism may limit sexual dysfunction. AIM: To summarize effects of vilazodone (40 mg/day, with food) on sexual function in adults with MDD, /data was used from/ three Phase III studies: two 8-week, placebo-controlled studies and a 52-week open-label study . Sexual function was assessed by analyzing changes from baseline to end of treatment (EOT) using validated measures. Population included 869 patients (vilazodone, 436; placebo, 433) from placebo-controlled studies and 599 patients from the open-label study. Sexual dysfunction prevalence was high (50%, men; 68%, women) before treatment and declined during treatment in vilazodone and placebo groups, indicating improvement on average. At EOT, stable/improved sexual function was observed in > or = 91% of patients in placebo-controlled studies; treatment group differences in sexual dysfunction at EOT were not statistically significant for either sex. Differences vs. placebo in changes from baseline of sexual function scores were small and were generally not statistically significant; effect sizes (Cohen's D) were generally of low magnitude. In the placebo-controlled studies, 8.0% of vilazodone-treated patients and 0.9% of placebo-treated patients reported > or = 1 sexual-function-related treatment-emergent adverse event (P<0.001). Half of men and two thirds of women with MDD had sexual dysfunction at baseline; sexual function improved on average in both vilazodone and placebo groups. Results suggest that vilazodone may have a small adverse impact on sexual function in adults with MDD relative to the high prevalence of sexual dysfunction at baseline.
PMID:23216998 Clayton AH et al; J Sex Med 10 (10): 2465-76 (2013)
/BOXED WARNING/ WARNING: SUICIDAL THOUGHTS AND BEHAVIORS. Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies. These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24; there was a reduction in risk with antidepressant use in patients aged 65 and older. In patients of all ages who are started on antidepressant therapy, monitor closely for clinical worsening and for emergence of suicidal thoughts and behaviors. Advise families and caregivers of the need for close observation and communication with the prescriber. Viibryd is not approved for use in pediatric patients.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
Worsening of depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior may occur in both adult and pediatric patients with major depressive disorder or other psychiatric disorders, whether or not they are taking antidepressants. This risk may persist until clinically important remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. However, there has been a long-standing concern that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term, placebo-controlled studies of antidepressants (i.e., selective serotonin-reuptake inhibitors (SSRIs) and other antidepressants) have shown an increased risk of suicidality in children, adolescents, and young adults (18-24 years of age) with major depressive disorder and other psychiatric disorders. An increased suicidality risk was not demonstrated with antidepressants compared with placebo in adults older than 24 years of age, and a reduced risk was observed in adults 65 years of age or older. The US Food and Drug Administration (FDA) recommends that all patients being treated with antidepressants for any indication be appropriately monitored and closely observed for clinical worsening, suicidality, and unusual changes in behavior, particularly during initiation of therapy (i.e., the first few months) and during periods of dosage adjustments. Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, also should be advised to monitor patients on a daily basis for the emergence of agitation, irritability, or unusual changes in behavior as well as the emergence of suicidality, and to report such symptoms immediately to a health-care provider. Although a causal relationship between the emergence of symptoms such as anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia, hypomania, and/or mania and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality. Consequently, consideration should be given to changing the therapeutic regimen or discontinuing therapy in patients whose depression is persistently worse or in patients experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, particularly if such manifestations are severe, abrupt in onset, or were not part of the patient's presenting symptoms. If a decision is made to discontinue therapy, vilazodone dosage should be tapered as rapidly as is feasible but consideration should be given to the risks of abrupt discontinuance. FDA also recommends that the drugs be prescribed in the smallest quantity consistent with good patient management, in order to reduce the risk of overdosage.
American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014, p. 2455
Potentially life-threatening serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions have been reported with antidepressants alone, but particularly with concurrent use of other serotonergic drugs (including serotonin (5-hydroxytryptamine; 5-HT) type 1 receptor agonists (triptans)), drugs that impair the metabolism of serotonin (e.g., MAO inhibitors), or antipsychotics or other dopamine antagonists. Manifestations of serotonin syndrome may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination), and/or GI symptoms (e.g., nausea, vomiting, diarrhea). In its most severe form, serotonin syndrome may resemble NMS, which is characterized by hyperthermia, muscle rigidity, autonomic instability with possible rapid fluctuation in vital signs, and mental status changes. Patients receiving vilazodone should be monitored for the development of serotonin syndrome or NMS-like signs and symptoms. Concurrent or recent (i.e., within 2 weeks) therapy with MAO inhibitors intended to treat depression is contraindicated. If concurrent therapy with vilazodone and a 5-HT1 receptor agonist (triptan) is clinically warranted, the patient should be observed carefully, particularly during initiation of therapy, when dosage is increased, or when another serotonergic agent is initiated. Concomitant use of vilazodone and serotonin precursors (e.g., tryptophan) is not recommended. If signs and symptoms of serotonin syndrome or NMS occur, treatment with vilazodone and any concurrently administered serotonergic or antidopaminergic agents, including antipsychotic agents, should be immediately discontinued and supportive and symptomatic treatment initiated.
American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014, p. 2455
Infants exposed to selective serotonin-reuptake inhibitors (SSRIs) in pregnancy may have an increased risk for persistent pulmonary hypertension of the newborn (PPHN). PPHN occurs in 1-2 per 1,000 live births in the general population and is associated with substantial neonatal morbidity and mortality. Several recent epidemiologic studies suggest a positive statistical association between SSRI use (including Viibryd) in pregnancy and PPHN. Other studies do not show a significant statistical association.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
For more Drug Warnings (Complete) data for Vilazodone (16 total), please visit the HSDB record page.
Vilazodone is approved for treatment of major depressive disorder.
FDA Label
Vilazodone increases serotonin levels in the brain by inhibiting the reuptake of serotonin while acting as a partial agonist on serotonin-1A receptors. Due to this activity vilazodone has sometimes been referred to as a selective partial agonist and reuptake inhibitor (SPARI).
Antidepressive Agents
Mood-stimulating drugs used primarily in the treatment of affective disorders and related conditions. Several MONOAMINE OXIDASE INHIBITORS are useful as antidepressants apparently as a long-term consequence of their modulation of catecholamine levels. The tricyclic compounds useful as antidepressive agents (ANTIDEPRESSIVE AGENTS, TRICYCLIC) also appear to act through brain catecholamine systems. A third group (ANTIDEPRESSIVE AGENTS, SECOND-GENERATION) is a diverse group of drugs including some that act specifically on serotonergic systems. (See all compounds classified as Antidepressive Agents.)
Selective Serotonin Reuptake Inhibitors
Compounds that specifically inhibit the reuptake of serotonin in the brain. (See all compounds classified as Selective Serotonin Reuptake Inhibitors.)
Serotonin 5-HT1 Receptor Agonists
Endogenous compounds and drugs that specifically stimulate SEROTONIN 5-HT1 RECEPTORS. Included under this heading are agonists for one or more of the specific 5-HT1 receptor subtypes. (See all compounds classified as Serotonin 5-HT1 Receptor Agonists.)
N - Nervous system
N06 - Psychoanaleptics
N06A - Antidepressants
N06AX - Other antidepressants
N06AX24 - Vilazodone
Absorption
Vilazodone's bioavailability is 72% when taken with food.
Route of Elimination
1% of the dose is recovered unchanged in the urine and 2% of the dose is recovered unchanged in the feces.
Volume of Distribution
Vilazodone's volume of distribution is unknown but large
Clearance
Clearance of vilazodone is 19.9-25.1L/h in patients with mild to moderate renal impairment compared to 26.4-26.9L/h in healthy controls.
Vilazodone concentrations peak at a median of 4-5 hours (Tmax) after administration and decline with a terminal half-life of approximately 25 hours. The absolute bioavailability of vilazodone is 72% with food. Administration of VIIBRYD with food (high fat or light meal) increases oral bioavailability (Cmax increased by approximately 147-160%, and AUC increased by approximately 64-85%).
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
Vilazodone is widely distributed and approximately 96-99% protein-bound.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
Vilazodone is excreted into the milk of lactating rats.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
Vilazodone is mainly metabolized by cytochrome P450(CYP)3A4 and also to a minor extent by CYP2C19 and CYP 2D6. Although the metabolic pathway for vilazodone has not been fully studied, a proposed mechanism for metabolism in rats was published in 2017.
Viibryd is extensively metabolized through CYP and non-CYP pathways (possibly by carboxylesterase), with only 1% of the dose recovered in the urine and 2% of the dose recovered in the feces as unchanged vilazodone. CYP3A4 is primarily responsible for its metabolism among CYP pathways, with minor contributions from CYP2C19 and CYP2D6. In vitro studies with human microsomes and human hepatocytes indicate that vilazodone is unlikely to inhibit or induce the metabolism of other CYP (except for CYP2C8) substrates; and an in vivo study with probe substrates for CYP2C19, 2D6 and 3A4 showed vilazodone did not alter the pharmacokinetics of the probe substrates. However, an in vivo study with probe substrate for CYP2C19 demonstrated a minor induction of CYP2C19. Strong inhibitors of CYP3A4 (e.g., ketoconazole) can reduce the metabolism of vilazodone in vivo and increase exposure. Conversely, strong inducers of CYP3A4 (e.g., carbamazepine) can decrease vilazodone exposure.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
25 hours. Other studies show a half life of 245.2h with a single 40mg dose and 28.93.2h with repeated doses.
Vilazodone /has/ a terminal half-life of approximately 25 hours.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
Vilazodone selectively inhibits serotonin reuptake in the central nervous system as well as acting as a partial agonist of 5HT-1A receptors. The exact mechanism for how these effects translate to its antidepressant effects are not known, though there is an association between these effects and antidepressive activity.
Vilazodone has been reported to be an inhibitor of 5-hydoxytryptamine (5-HT) reuptake and a partial agonist at 5-HT1A receptors. Using [35S]GTPgammaS binding in rat hippocampal tissue, vilazodone was demonstrated to have an intrinsic activity comparable to the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Vilazodone (1-10 mg/kg p.o.) dose-dependently displaced in vivo [3H]DASB (N,N-dimethyl-2-(2-amino-4-cyanophenylthio)benzylamine) binding from rat cortex and hippocampus, indicating that vilazodone occupies 5-HT transporters in vivo. Using in vivo microdialysis, vilazodone (10 mg/kg p.o.) was demonstrated to cause a 2-fold increase in extracellular 5-HT but no change in noradrenaline or dopamine levels in frontal cortex of freely moving rats. In contrast, administration of 8-OH-DPAT (0.3 mg/kg s.c.), either alone or in combination with a serotonin specific reuptake inhibitor (SSRI; paroxetine, 3 mg/kg p.o.), produced no increase in cortical 5-HT whilst increasing noradrenaline and dopamine 2 and 4 fold, respectively. A 2-fold increase in extracellular 5-HT levels (but no change in noradrenaline or dopamine levels) was observed after combination of the 5-HT(1A) receptor antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(pyridinyl)cyclohexanecarboxamide) (WAY-100635; 0.3 mg/kg s.c.) and paroxetine (3 mg/kg p.o.). In summary, vilazodone behaved as a high efficacy partial agonist at the rat hippocampal 5-HT1A receptors in vitro and occupied 5-HT transporters in vivo. In vivo vilazodone induced a selective increase in extracellular levels of 5-HT in the rat frontal cortex. This profile was similar to that seen with a 5-HT1A receptor antagonist plus an SSRI but in contrast to 8-OH-DPAT either alone or in combination with paroxetine.
PMID:15740724 Hughes ZA et al; Eur J Pharmacol 510 (1-2): 49-57 (2005)
The mechanism of the antidepressant effect of vilazodone is not fully understood but is thought to be related to its enhancement of serotonergic activity in the CNS through selective inhibition of serotonin reuptake. Vilazodone is also a partial agonist at serotonergic 5-HT1A receptors; however, the net result of this action on serotonergic transmission and its role in vilazodone's antidepressant effect are unknown.
NIH; DailyMed. Current Medication Information for Viibryd (Vilazodone Hydrochloride) Tablet Viibryd (Vilazodone Hydrochloride) Kit (Revised: July 2014). Available from, as of July 30, 2014: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=4c55ccfb-c4cf-11df-851a-0800200c9a66
The recently approved antidepressant vilazodone, a serotonin (5-HT)1A receptor partial agonist/selective 5-HT reuptake inhibitor offers new possibilities to study the underlying mechanisms of depression pharmacotherapy and of 5-HT augmenting antidepressants. ... 5-HT levels /were measured/ in two subregions of the rat prefrontal cortex by microdialysis, and 5-hydroxytryptophan (5-HTP) accumulation and tissue 5-HT concentrations ex vivo. Vilazodone-induced maximal 5-HT levels were similar in the medial and the lateral cortex and were up to sixfold higher than those induced by paroxetine, citalopram, or fluoxetine tested in parallel. Depolarization/autoreceptor-insensitive 5-HT release by vilazodone could be excluded. The citalopram (1 uM, locally infused)-induced increase of 5-HT was further increased by vilazodone (1 mg/kg i.p.), but not by citalopram (10 mg/kg i.p.). Unlike fluoxetine, vilazodone-induced extracellular 5-HT output was not potentiated by cotreatment with the 5-HT1A receptor blocker N-[2-(4-{2-methoxyphenyl}-1-piperazinyl)-ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY 100635). In contrast to fluoxetine, vilazodone exhibited intrinsic 5-HT1A agonist activity: it reduced, similar to (+/-)-8-hydroxy-2-(dipropylamino)-tetralin (8-OH-DPAT), 5-HTP accumulation in striatum and n. raphe of reserpinized rats. Hence, vilazodone's agonistic actions must be 5-HT1A receptor-related since endogenous 5-HT is lacking in the reserpine-depleted animal. In spite of high intrinsic 5-HT1A activity in reserpinized rats, the net effect of vilazodone at release-regulating 5-HT1A autoreceptors must be inhibitory, leading to markedly increased 5-HT output. Another possibility is that vilazodone rapidly desensitizes autoinhibitory 5-HT1A receptors by an unknown mechanism.
PMID:24419272 van Amsterdam C, Seyfried CA; Psychopharmacology 231 (12): 2547-58 (2014)
This study examined the effect of vilazodone, a combined serotonin (5-HT) reuptake inhibitor and 5-HT(1A) receptor partial agonist, paroxetine and fluoxetine on the sensitivity of 5-HT(1A) autoreceptors of serotonergic dorsal raphe nucleus neurons in rats. These effects were assessed by determining the intravenous dose of (+/-)-8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) required to suppress the basal firing rate of these neurons by 50% (ID50) in anesthetized rats using in vivo electrophysiology. 5-HT uptake inhibition was determined by the ability of the compounds to reverse (+/-)-p-chloroamphetamine (PCA)-induced rat hypothalamic 5-HT depletion ex vivo. Acute vilazodone administration (0.63 and 2.1 umol/kg, s.c.), compared with vehicle, significantly increased (2-3-fold) the ID50 of 8-OH-DPAT at 4 hr, but not 24 hr after administration. Subchronic administration (3 days) significantly increased the ID50 value at 4 hr (3-4-fold) and at 24 hr (approximately 2-fold). In contrast, paroxetine and fluoxetine at doses that were supramaximal for 5-HT uptake inhibition did not significantly alter the ID50 value of 8-OH-DPAT after acute or subchronic administration. Vilazodone antagonized the action of PCA 3.5 hr and 5 hr after a single dose (ID50 1.49 and 0.46 umol/kg, s.c., respectively), but was inactive 18 hr post-administration, corroborating the electrophysiological results at 24 hr following acute administration. The results are consistent with the concept of rapid and, following repeated treatment, prolonged inhibition of 5-HT(1A) autoreceptors by vilazodone. This effect could occur by either direct interaction with, or desensitization of, these receptors, an effect which cannot be ascribed to vilazodone's 5-HT reuptake inhibiting properties.
PMID:23872377 Ashby CR Jr et al; Eur J Pharmacol 714 (1-3): 359-65 (2013)
LOOKING FOR A SUPPLIER?
