Effexor XR (Venlafaxine) Facts

Effexor (Venlafaxine hydrochloride), an antidepressant (mood elevator), is indicated for the treatment of depression, generalized anxiety disorder, social anxiety disorder (social phobia) and panic disorder. This medication is sometimes prescribed for other uses. Effexor blocks the ability of the nerve terminals in the brain to bind and break down serotonin and norepinephrine so that more is available for the brain to use. Abnormally low levels of serotonin and norepinephrine may play a role in conditions such as depression and anxiety disorders.

The most common Effexor side effects include nausea, dizziness, insomnia, somnolence, and dry mouth.

Effexor is associated with a very troublesome discontinuation syndrome. To avoid this syndrome, Effexor (venlafaxine) should be tapered by reducing the daily dose by no more than 75 mg at one-week intervals.

• Absorption: Absolute bioavailability is 45% and well absorbed (at least 92%) of single oral dose. Steady-state concentrations of venlafaxine and O-desmethylvenlafaxine (ODV) in plasma are attained within 3 days of oral dose. Exhibits linear kinetics over dose range 75 to 450mg/day.
• Metabolism: Extensively metabolized in the liver. The only major metabolite is ODV, which is active.
• Elimination half-life: elimination half-life of venlafaxine is 5 ± 2 and 11 ± 2 hours of O-desmethylvenlafaxine (ODV)
• Excretion: Renal elimination of venlafaxine and its metabolite is the primary route of excretion. Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as either unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%). Renal elimination of venlafaxine and its metabolites is the primary route of excretion.

• powerful antidepressant
• high therapeutic success rate [4]
• effective in depression, resistant to other antidepressants [5, 7]
• more effective than fluoxetine and paroxetine for remission of depressive symptoms [6]
• rapid onset of action [18]

• high rate of nausea and vomiting
• can increase blood pressure
• high rate of severe withdrawal syndrome [3]
• toxicity in overdose (cardiovascular toxicity, rhabdomyolysis) [19, 20]
• high risk of suicide [21]

• diabetic neuropathy
• migraine prophylaxis [11]
• hot-flashes
• post-traumatic stress disorder (PTSD) [10]
• fibromyalgia [12]
• tension-type headache [13]
• chronic pain [14]
• polyneuropathy [16]
• premenstrual dysphoric disorder [15]
• attention deficit hyperactivity disorder (ADD/ADHD) [17]

Effexor for fibromyalgia
Some studies have shown that Effexor may be effective for fibromyalgia treatment - though the drug is not approved for this use [12]. Although it is not entirely clear how Effexor works for fibromyalgia, the drug may help block the nerve pain signals in the spinal cord or brain. This may help with the pain caused by fibromyalgia. The studies have shown that Effexor can provide pain relief and decrease disability due to fibromyalgia. People taking Effexor for fibromyalgia also showed improvement in anxiety or depression symptoms.

Effexor (venlafaxine) blocks the reuptake of serotonin, noradrenaline and, to a lesser extent, dopamine. Effexor has the flexibility of being an SSRI at lower doses and an SNRI at higher doses.

Effexor (Venlafaxine) antinociceptive effects
Effexor (venlafaxine) has an analgesic effect that is independent of its antidepressant activity. The study has shown that antinociceptive effect of venlafaxine is mainly influenced by the kappa- and delta-opioid receptor subtypes combined with the alpha2-adrenergic receptor. These results suggest a potential use of venlafaxine in the management of some pain syndromes [9].

• Effexor (Venlafaxine) reviews and ratings (recommended medication by 71% of reviewers): http://psychcentral.com/meds/effexor.html
• Effexor discussion: http://www.drugs.com/forum/featured-drugs/effexor-20972.html
• Effexor (Venlafaxine) discussion: http://www.depressionforums.org/forums/index.php?showforum=54
• Effexor, Venlafaxine Forum: http://www.topix.net/forum/drug/effexor
• Effexor withdrawal boards
• How to taper off Effexor -- Method 1 on Drugs.com
• Effexor withdrawal on Drugs.com
• Horrific Withdrawal Off Effexor on MedicalNewsToday.com
• How to get off Effexor symptom free "bead method" on Topix.com

• Effexor XR official website
• Venlafaxine - Drug Information Provided by Lexi-Comp: Merck Manual
• AskAPatient.com: Ratings for effexor xr: side effects and patient comments - Consumer ratings reports for the effexor xr. Includes patient rankings on scale of 1-5, comments, side effects, sex, and age.
• MedlinePlus Drug Information: Venlafaxine
• Venlafaxine ( Effexor, Efexor ) Biopsychiatry.com
• Effexor (venlafaxine) - The Good, The Bad and The Funny: http://www.crazymeds.org/effexor.html

• 1. U.S. Food and Drug Administration. Effexor (Venlafaxine) U.S. Prescribing Information. Available at (PDF format): Prescribing Information
• 2. U.S. Food and Drug Administration. Effexor XR (Venlafaxine XR) U.S. Prescribing Information. Available at (PDF format): Prescribing Information
• 3. Fava M, Mulroy R, Alpert J, Nierenberg AA, Rosenbaum JF. Emergence of adverse events following discontinuation of treatment with extended-release venlafaxine. Am J Psychiatry. 1997 Dec;154(12):1760-2. PubMed
• 4. Einarson TR, Arikian SR, Casciano J, Doyle JJ. Comparison of extended-release venlafaxine, selective serotonin reuptake inhibitors, and tricyclic antidepressants in the treatment of depression: a meta-analysis of randomized controlled trials. Clin Ther. 1999 Feb;21(2):296-308. PubMed
• 5. Sa'iz-Ruiz J, Iba'nez A, Di'az-Marsa' M, Arias F, Padi'n J, Marti'n-Carrasco M, Montes JM, Ferrando L, Carrasco JL, Marti'n-Ballesteros E, Jorda' L, Chamorro L. Efficacy of venlafaxine in major depression resistant to selective serotonin reuptake inhibitors. Prog Neuropsychopharmacol Biol Psychiatry. 2002 Oct;26(6):1129-34. PubMed
• 6. Shelton C, Entsuah R, Padmanabhan SK, Vinall PE. Venlafaxine XR demonstrates higher rates of sustained remission compared to fluoxetine, paroxetine or placebo. Int Clin Psychopharmacol. 2005 Jul;20(4):233-8. PubMed
• 8. Kaplan EM. Efficacy of venlafaxine in patients with major depressive disorder who have unsustained or no response to selective serotonin reuptake inhibitors: an open-label, uncontrolled study. Clin Ther. 2002 Jul;24(7):1194-200. PubMed
• 9. Schreiber S, Backer MM, Pick CG. The antinociceptive effect of venlafaxine in mice is mediated through opioid and adrenergic mechanisms. Neurosci Lett. 1999 Oct 1;273(2):85-8. PubMed
• 10. Pae CU, Lim HK, Ajwani N, Lee C, Patkar AA. Extended-release formulation of venlafaxine in the treatment of post-traumatic stress disorder. Expert Rev Neurother. 2007 Jun;7(6):603-15. PubMed
• 11. Ozyalcin SN, Talu GK, Kiziltan E, Yucel B, Ertas M, Disci R. The efficacy and safety of venlafaxine in the prophylaxis of migraine. Headache. 2005 Feb;45(2):144-52. PubMed
• 12. Dwight MM, Arnold LM, O'Brien H, Metzger R, Morris-Park E, Keck PE Jr. An open clinical trial of venlafaxine treatment of fibromyalgia. Psychosomatics. 1998 Jan-Feb;39(1):14-7. PubMed
• 13. Zissis NP, Harmoussi S, Vlaikidis N, Mitsikostas D, Thomaidis T, Georgiadis G, Karageorgiou K. A randomized, double-blind, placebo-controlled study of venlafaxine XR in out-patients with tension-type headache. Cephalalgia. 2007 Apr;27(4):315-24. Epub 2007 Mar 7. PubMed
• 14. Taylor K, Rowbotham MC. Venlafaxine hydrochloride and chronic pain. West J Med. 1996 Sep;165(3):147-8.
• 15. Cohen LS, Soares CN, Lyster A, Cassano P, Brandes M, Leblanc GA. Efficacy and tolerability of premenstrual use of venlafaxine (flexible dose) in the treatment of premenstrual dysphoric disorder. J Clin Psychopharmacol. 2004 Oct;24(5):540-3. PubMed
• 16. Sindrup SH, Bach FW, Madsen C, Gram LF, Jensen TS. Venlafaxine versus imipramine in painful polyneuropathy: a randomized, controlled trial. Neurology. 2003 Apr 22;60(8):1284-9. PubMed
• 17. Mukaddes NM, Abali O. Venlafaxine in children and adolescents with attention deficit hyperactivity disorder. Psychiatry Clin Neurosci. 2004 Feb;58(1):92-5. PubMed
• 18. Andrews JM, Ninan PT, Nemeroff CB. Venlafaxine: a novel antidepressant that has a dual mechanism of action. Depression. 1996;4(2):48-56. PubMed
• 19. Howell C, Wilson AD, Waring WS. Cardiovascular toxicity due to venlafaxine poisoning in adults: a review of 235 consecutive cases. Br J Clin Pharmacol. 2007 Aug;64(2):192-7. Epub 2007 Feb 12. PubMed
• 20. Pascale P, Oddo M, Pacher P, Augsburger M, Liaudet L. Severe rhabdomyolysis following venlafaxine overdose. Ther Drug Monit. 2005 Oct;27(5):562-4. PubMed
• 21. Rubino A, Roskell N, Tennis P, Mines D, Weich S, Andrews E. Risk of suicide during treatment with venlafaxine, citalopram, fluoxetine, and dothiepin: retrospective cohort study. BMJ. 2007 Feb 3;334(7587):242. Epub 2006 Dec 12. PubMed