|
Venlafaxine
resources
|
|
|
|
|
|
DRUG INFO
Venlafaxine
Drug Name:
Venlafaxine
Indication: For the treatment of severe depression
Pharmacology: Venlafaxine, an antidepressant agent structurally unrelated to other antidepressants, is used to treat melancholia, generalized anxiety disorder (GAD), panic disorder, post-traumatic stress disorder, and hot flashes in breast cancer survivors.
Mechanism Of Action: Venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), inhibit the reuptake of both serotonin and norepinephrine with a potency greater for the 5-HT than for the NE reuptake process. Both venlafaxine and the ODV metabolite have weak inhibitory effects on the reuptake of dopamine but, unlike the tricyclics and similar to SSRIs, they are not active at histaminergic, muscarinic, or alpha(1)-adrenergic receptors.
Drug Category: Antidepressants; Analgesics; Antidepressants; ATC:N06AX16
Brand Names/Synonyms: CHEMBANK1685; Effexor; Effexor Xr; Elafax; Venlafaxina [Inn-Spanish]; Venlafaxine; Venlafaxine [Inn:Ban]; Venlafaxinum [Inn-Latin]
Dosage Forms: CAPSULE (SUSTAINED-RELEASE)
Absorption: Not Available
Interactions: Interactions for Venlafaxine:
As with all drugs, the potential for interaction by a variety of mechanisms is a possibility.
Alcohol: A single dose of ethanol (0.5 g/kg) had no effect on the pharmacokinetics of venlafaxine or O-desmethylvenlafaxine (ODV) when venlafaxine was administered at 150 mg/day in 15 healthy male subjects. Additionally, administration of venlafaxine in a stable regimen did not exaggerate the psychomotor and psychometric effects induced by ethanol in these same subjects when they were not receiving venlafaxine.
Cimetidine: Concomitant administration of cimetidine and venlafaxine in a steady-state study for both drugs resulted in inhibition of first-pass metabolism of venlafaxine in 18 healthy subjects. The oral clearance of venlafaxine was reduced by about 43%, and the exposure (AUC) and maximum concentration (Cmax) of the drug were increased by about 60%. However, coadministration of cimetidine had no apparent effect on the pharmacokinetics of ODV, which is present in much greater quantity in the circulation than venlafaxine. The overall pharmacological activity of venlafaxine plus ODV is expected to increase only slightly, and no dosage adjustment should be necessary for most normal adults. However, for patients with pre-existing hypertension, and for elderly patients or patients with hepatic dysfunction, the interaction associated with the concomitant use of venlafaxine and cimetidine is not known and potentially could be more pronounced. Therefore, caution is advised with such patients.
Diazepam: Under steady-state conditions for venlafaxine administered at 150 mg/day, a single 10 mg dose of diazepam did not appear to affect the pharmacokinetics of either venlafaxine or ODV in 18 healthy male subjects. Venlafaxine also did not have any effect on the pharmacokinetics of diazepam or its active metabolite, desmethyldiazepam, or affect the psychomotor and psychometric effects induced by diazepam.
Haloperidol: Venlafaxine administered under steady-state conditions at 150 mg/day in 24 healthy subjects decreased total oral-dose clearance (Cl/F) of a single 2 mg dose of haloperidol by 42%, which resulted in a 70% increase in haloperidol AUC. In addition, the haloperidol Cmax increased 88% when coadministered with venlafaxine, but the haloperidol elimination half-life was unchanged. The mechanism explaining this finding is unknown.
Lithium: The steady-state pharmacokinetics of venlafaxine administered at 150 mg/day were not affected when a single 600 mg oral dose of lithium was administered to 12 healthy male subjects. ODV also was unaffected. Venlafaxine had no effect on the pharmacokinetics of lithium.
Drugs Highly Bound to Plasma Proteins: Venlafaxine is not highly bound to plasma proteins; therefore, administration of Effexor XR to a patient taking another drug that is highly protein bound should not cause increased free concentrations of the other drug.
Drugs that Inhibit Cytochrome P450 Isoenzymes: CYP2D6 Inhibitors: In vitro and in vivo studies indicate that venlafaxine is metabolized to its active metabolite, ODV, by CYP2D6, the isoenzyme that is responsible for the genetic polymorphism seen in the metabolism of many antidepressants. Therefore, the potential exists for a drug interaction between drugs that inhibit CYP2D6-mediated metabolism of venlafaxine, reducing the metabolism of venlafaxine to ODV, resulting in increased plasma concentrations of venlafaxine and decreased concentrations of the active metabolite. CYP2D6 inhibitors such as quinidine would be expected to do this, but the effect would be similar to what is seen in patients who are genetically CYP2D6 poor metabolizers. Therefore, no dosage adjustment is required when venlafaxine is coadministered with a CYP2D6 inhibitor.
The concomitant use of venlafaxine with drug treatment(s) that potentially inhibits both CYP2D6 and CYP3A4, the primary metabolizing enzymes for venlafaxine, has not been studied.
Therefore, caution is advised should a patient's therapy include venlafaxine and any agent(s) that produce simultaneous inhibition of these two enzyme systems.
Drugs Metabolized by Cytochrome P450 Isoenzymes: CYP2D6: In vitro studies indicate that venlafaxine is a relatively weak inhibitor of CYP2D6. These findings have been confirmed in a clinical drug interaction study comparing the effect of venlafaxine with that of fluoxetine on the CYP2D6-mediated metabolism of dextromethorphan to dextrorphan.
Imipramine - Venlafaxine did not affect the pharmacokinetics of imipramine and 2-OH-imipramine. However, desipramine AUC, Cmax, and Cmin increased by about 35% in the presence of venlafaxine. The 2-OH-desipramine AUC's increased by at least 2.5 fold (with venlafaxine 37.5 mg q12h) and by 4.5 fold (with venlafaxine 75 mg q12h). Imipramine did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of elevated 2-OH-desipramine levels is unknown.
Risperidone - Venlafaxine administered under steady-state conditions at 150 mg/day slightly inhibited the CYP2D6-mediated metabolism of risperidone (administered as a single 1 mg oral dose) to its active metabolite, 9-hydroxyrisperidone, resulting in an approximate 32% increase in risperidone AUC. However, venlafaxine coadministration did not significantly alter the pharmacokinetic profile of the total active moiety (risperidone plus 9-hydroxyrisperidone).
CYP3A4: Venlafaxine did not inhibit CYP3A4 in vitro. This finding was confirmed in vivo by clinical drug interaction studies in which venlafaxine did not inhibit the metabolism of several CYP3A4 substrates, including alprazolam, diazepam, and terfenadine.
Indinavir - In a study of 9 healthy volunteers, venlafaxine administered under steady-state conditions at 150 mg/day resulted in a 28% decrease in the AUC of a single 800 mg oral dose of indinavir and a 36% decrease in indinavir Cmax. Indinavir did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of this finding is unknown.
CYP1A2: Venlafaxine did not inhibit CYP1A2 in vitro. This finding was confirmed in vivo by a clinical drug interaction study in which venlafaxine did not inhibit the metabolism of caffeine, a CYP1A2 substrate.
CYP2C9: Venlafaxine did not inhibit CYP2C9 in vitro. In vivo, venlafaxine 75 mg by mouth every 12 hours did not alter the pharmacokinetics of a single 500 mg dose of tolbutamide or the CYP2C9 mediated formation of 4-hydroxy-tolbutamide.
CYP2C19: Venlafaxine did not inhibit the metabolism of diazepam, which is partially metabolized by CYP2C19.
CNS-Active Drugs: The risk of using venlafaxine in combination with other CNS-active drugs has not been systematically evaluated (except in the case of those CNS-active drugs noted above).
Consequently, caution is advised if the concomitant administration of venlafaxine and such drugs is required. Based on the mechanism of action of venlafaxine and the potential for serotonin syndrome, caution is advised when venlafaxine is co-administered with other drugs that may affect the serotonergic neurotransmitter systems, such as triptans, serotonin reuptake inhibitors (SRIs), or lithium.
Electroconvulsive Therapy: There are no clinical data establishing the benefit of electroconvulsive therapy combined with Effexor XR (venlafaxine hydrochloride) extended-release capsules treatment.
*Based on the number of men and women as appropriate.
Chemical IUPAC Name: 1-[2-dimethylamino-1-(4-methoxyphenyl)-ethyl]cyclohexan-1-ol
Chemical Formula: C17H27NO2
Half Life: 5 hours
Drug Type: Approved Drug
# Accession No: APRD00125
CAS Registry Number: 93413-69-5
|
|
|
|
|
|
Venlafaxine News
(When available)
US court approves Wyeth-Teva settlement on Effexor 15 Jan 2006
Globes, ...(Nasdaq: TEVA ; TASE: TEVA) and Wyeth (NYSE: WYE) over Teva's application to market a generic version of Wyeth's anti-depressant Effexor. ...
Wyeth settles with Teva over Effexor generic Jan 13, 2006
Reuters ...agreed to settle litigation with Teva Pharmaceutical Industries Ltd (TEVA.O: Quote, Profile, Research) over a generic version of Wyeth's depression drug Effexor ...
Wyeth-Teva Settlement Finalized Jan 13, 2006
Finanzen.net, ...announced today that the settlement of the litigation between Wyeth and Teva concerning Teva's application to market a generic version of Wyeth's Effexor(R) XR ...
Wyeth 2006 forecast misses Street views Jan 9, 2006
San Jose Mercury News, The maker of popular antidepressant Effexor, Centrum vitamins and Advil pain reliever, also said its profit for the year just ended will slightly exceed its ...
The Down Side of Popping Pills Jan 11, 2006
AlterNet, Wellbutrin, Neurontin, Seroquel, Depakote, Effexor, Inderal, Trileptal, Paxil, Zyprexa, Lamictal, Abilify, I've taken them all. ...
Prescription for Trouble Jan 8, 2006
ABC30.com, Consumer Reports' Joel Gurin. Zoloft, Effexor, and other antidepressants, particularly when prescribed to young people. With most of ...
Wyeth forecasts 10 percent EPS growth in 2006 Jan 9, 2006
ABC News Wyeth said it was looking to regain growth of its depression drug Effexor, with international growth expected to be more "dynamic" than in the US market. ...
Wyeth 2006 Forecast Misses Street Views Jan 9, 2006
WJLA, ...with several drugs producing blockbuster sales and plans to seek approval for six new medicines.The maker of popular antidepressant Effexor, Centrum vitamins ...
The antidepressants to watch in '06 Jan 4, 2006
CNN Wyeth (up $0.43 to $46.50, Research) bills its drug Effexor XR as the world's top selling antidepressant. The numbers bear this out, but they're slipping. ...
Antidepressants Don't Appear to Raise Suicide Risk, Study Shows Jan 1, 2006
Bloomberg 1 (Bloomberg) -- Antidepressants such as Wyeth's Effexor and Eli Lilly & Co.'s Prozac don't appear to pose a higher risk of suicide in the six months after they ...
The fool's gold that heals Jan 13, 2006
Guardian Unlimited, 6.67 points. The scores for Zoloft were 9.96 (placebo, 7.93); Effexor, 11.54 (placebo, 8.38); Celexa, 9.69 (placebo, 7.71). The ...
The Health Report: Ring in the New Year by Understanding Your ... Jan 5, 2006
DeadBrain.us (satire) ..."Right, we're talking about medication for the head. Yes. "Effexor, well it should speak for itself," he chuckled, before pounding his fists on the podium. ...
Parents of Poisoned Teen File Lawsuit Jan 12, 2006
WTOP, Vassiliev's girlfriend. Susan Furlough blames her son's actions on the antidepressant drug Effexor and on inadequate therapy. The ...
Parents of slain teen file $6 million suit Jan 12, 2006
Baltimore Sun, Susan Furlough blames her son's actions on the antidepressant drug Effexor - which faced international scrutiny for its possible behavioral side effects in ...
I Thank You Jan 13, 2006
New York Times, ...thanks respectively to Wyeth-Ayerst Laboratories and Stuart Pharmaceuticals for further expanding that narrow channel of joy by manufacturing Effexor and Elavil ...
A New Year’s Resolution Jan 4, 2006
PR Web (press release), Although medications such as Effexor, Prozac, Paxil, Wellbutrin, Zoloft and Celexa are considered non-addictive, there are many people who describe vast swings ...
DR GARETH: MY BREATH'S A STINKER Dec 31, 2005
Glasgow Sunday Mail, Even without treatment it will clear up if left alone. QI HAVE suffered from depression for several years and my doctor has put me on a drug called Effexor. ...
Antidepressants Don’t Increase Suicide Risk Jan 3, 2006
Christian Broadcasting Network, ...sponsored studies on some of the most popular antidepressants, such as Prozac, Zoloft, Celexa, and others, such as Paxil, Lexapro, Effexor, Remeron, and ...
Drug makers face headache as patents expire Dec 18, 2005
Austin American-Statesman (subscription), Wyeth Pharmaceuticals will start losing exclusivity next year on its top-selling medication, depression drug Effexor, which had US sales of $2.3 billion last ...
US Stock-Index Futures Drop; Alcoa, United Technologies Fall ... Jan 10, 2006
Bloomberg Goldman, Sachs & Co. analyst Robert Barry raised his rating on GM's stock. Wyeth, the maker of the Effexor antidepressant, gained 5 cents to $47.57 in Germany. ...
US Stock-Index Futures Drop; Alcoa, United Technologies Fall ... Jan 10, 2006
Bloomberg Santiago and Parag Agarwal. Wyeth, the maker of the Effexor antidepressant, gained 6 cents to $47.58 in Germany. The company said ...
National and World Briefs Jan 9, 2006
Winston-Salem Journal, Wyeth, which makes the popular antidepressant Effexor, Centrum vitamins and the pain reliever Advil, also said its profit for the year just ended will slightly ...
7 days to the best sex ever! Jan 11, 2006
New York Daily News, I used to.". Dean told Weeks that following the loss of his company, he took the anti-depressant Effexor. "Many anti-depressants ...
FDA May Have Underestimated Drug Dangers Dec 26, 2005
WISC, ...the FDA approved them.". Zoloft, Effexor and other antidepressants, particularly when prescribed to young people. With most of these ...
Suicide Drops With Antidepressant Use Jan 3, 2006
FOX News The 10 drugs identified by the FDA are Prozac, Paxil, Zoloft, Effexor, Celexa, Lexapro, Luvox, Remeron, Serzone, and Wellbutrin. ...
Depression Weighs Heaviest on the Elderly Dec 31, 2005
PakTribune.com, ...among the elderly: SSRIs (selective serotonin reuptake inhibitors) such as Prozac, Zoloft and Paxil; and the even-newer non-SSRIs such as Wellbutrin and Effexor ...
Prescription Mix-Ups Common Dec 14, 2005
W*USA 9, ...her very ill. The yellow vial containing 100 mg Effexor was labeled Topomax -- and the 25 mg Topamax labeled Effexor. So, Jackson ...
Antidepressants (Eli Lilly & Co.'s Prozac) don't cause suicide ... Jan 3, 2006
EnjoyFrance.com, The drugs include in the original FDA warning were Effexor, Prozac, Pfizer Inc.'s Zoloft, GlaxoSmithKline Plc's Paxil, Solvay SA's Luvox, Biovail Corp.'s ...
Gene Variation Affects Tamoxifen's Benefit For Breast Cancer Dec 31, 2005
Medical News Today (press release), Their research has also found the antidepressant drug Paxil can prevent tamoxifen from being activated, while the antidepressant drug Effexor does not. ...
Franklin County Court Dec 16, 2005
Plattsburgh Press Republican, Jeror had been prescribed twice the recommended dosage of the powerful anti-depressant Effexor, which is not supposed to be prescribed to teens and is under ...
Pfighting Back Dec 19, 2005
Smartmoney.com ...defense this year of its schizophrenia treatment Zyprexa and Wyeth's (WYE) settlement of a fight with Teva Pharmaceutical (TEVA) over its antidepressant Effexor ...
Consumer Reports Examines Weaknesses of Current Drug-safety System Dec 27, 2005
Kansas City infoZine, ...asthma; Sibutramine (Meridia) for weight loss; SSRIs such as sertraline (Zoloft), and other antidepressants such as venlafaxine (Effexor), particularly when ...
End to patents means major headache for drug makers Dec 23, 2005
The Journal News.com, ...the Collegeville, Pa., division of New Jersey-based Wyeth, will start losing exclusivity next year on its top-selling drug, Effexor for depression, which had ...
Agent says VA suspect bipolar Dec 19, 2005
Fayetteville Online, Charland later told agents that he needed his prescription for Effexor when they asked him whether there was anything he wanted while he remained in custody ...
TeenScreen - New York Times - Danger Signs Dec 18, 2005
Media Monitors Network, Eighteen-year-old, Jason Hoffman, was on Celexa and Effexor when he shot three students and one teacher at a California High School. ...
Decision Resources Forecasts the Five Drugs that Will Achieve ... Dec 20, 2005
PR Newswire (press release), For example, sales of Wyeth's blockbuster antidepressant Effexor XR were flat in 2005, a reversal that the company attributed in part to increased competition ...
Man gets 40 years for '04 murder Dec 24, 2005
Springfield State Journal Register, Dyer. Killian testified that Boner probably was suffering from withdrawal from Effexor, an antidepressant he had been taking. Boner ...
Breast cancer: polymorphisms in Tamoxifen metabolizing genes ... Dec 23, 2005
Xagena.it, ...found the antidepressant drug Paroxetine ( Paxil ) can prevent Tamoxifen from being activated, while the antidepressant drug Venlafaxine ( Effexor ) does not. ...
Mother says she killed daughter to protect child from 'spirits' Dec 14, 2005
San Jose Mercury News, ...bipolar disorder. Police searching her apartment found a bottle of Effexor, a drug used to treat depression and anxiety. She remains ...
Murder suspect claimed spirits hurt baby Dec 14, 2005
The Register-Guard, Friends have said Young suffers from bipolar disorder. Police searching her apartment found a bottle of Effexor, a drug used to treat depression and anxiety. ...
The antidepressants to watch in '06 Jan 4, 2006
CNN Wyeth (up $0.43 to $46.50, Research) bills its drug Effexor XR as the world's top selling antidepressant. The numbers bear this out, but they're slipping. ...
Drug makers face headache as patents expire Dec 18, 2005
Austin American-Statesman (subscription), ...challengers. In 1997, Wyeth patented Effexor XR to improve on its initial version and extend the antidepressant's sales life until 2010. ...
Decision Resources Forecasts the Five Drugs that Will Achieve ... Dec 20, 2005
Yahoo! News (press release) For example, sales of Wyeth's blockbuster antidepressant Effexor XR were flat in 2005, a reversal that the company attributed in part to increased competition ...
|
|
|
