Effexor (Venlafaxine)

Effexor (Venlafaxine hydrochloride), an antidepressant (mood elevator) from SNRI class, is indicated for the treatment of depression, generalized anxiety disorder, social anxiety disorder (social phobia) and panic disorder. 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.

Effexor is associated with a very troublesome discontinuation syndrome. It happens when people hurriedly stop using Effexor. To avoid severe withdrawal symptoms, venlafaxine should be tapered step-by-step.

Some people cope reducing the dose by 37.50 mg at one-week intervals. Other can tolerate tapering by 5 mg every 10 days.

If the discontinuation is terrible, then very slow tapering and cutting the milligrammes at a rate 5-10% may be the way out. You may need about 3-4 weeks to stabilize after each step down.

Liquid formulation, splitter, and scales may help to measure the right amounts.

• Absorption: Absolute bioavailability is 45% and well absorbed (at least 92%). Steady-state concentrations of venlafaxine and O-desmethylvenlafaxine (ODV) in plasma are attained within 3 days. Exhibits linear kinetics over dose range 75 to 450 mg/day.
• Metabolism: Extensively metabolized in the liver. The only major metabolite is O-desmethylvenlafaxine, 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 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%).

• powerful antidepressant
• high therapeutic success rate [4]
• often effective for depression not responding to SSRIs [5, 8]
• highest remission rate for depression resistant to other antidepressants [6]
• more effective than other antidepressants for long-lasting 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 [1]

• 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 XR 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. The drug 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 some pain syndromes [9].

• Effexor XR (Venlafaxine) Reviews, Ratings by Patients on DrugLib.com
• Effexor (Venlafaxine) ratings (recommended by 69% of reviewers) on PsychCentral
• User Reviews for Effexor on Drugs.com
• Effexor User ratings and reviews on RevolutionHealth
• Effexor, Venlafaxine Forum on Topix
• Venlafaxine (Effexor) MyTherapy Discussion Forums
• Withdrawal boards
• How to taper off Effexor on Drugs.com
• Horrific Withdrawal Off Effexor on MedicalNewsToday.com

• Effexor XR official website
• Venlafaxine - Drug Information Provided by Lexi-Comp: Merck Manual

• 1. Tiihonen J, Lönnqvist J, Wahlbeck K, Klaukka T, Tanskanen A, Haukka J. Antidepressants and the risk of suicide, attempted suicide, and overall mortality in a nationwide cohort. Arch Gen Psychiatry. 2006 Dec;63(12):1358-67. PubMed
• 3. Fava M, Mulroy R, Alpert J, Nierenberg AA, Rosenbaum JF. Emergence of adverse events following discontinuation of extended-release venlafaxine. Am J Psychiatry. 1997 Dec;154(12):1760-2.
• 4. Einarson TR, Arikian, Casciano J, Doyle JJ. Comparison of extended-release venlafaxine, selective serotonin reuptake inhibitors, and tricyclic antidepressants in the treatment of depression. Clin Ther. 1999 Feb;21(2):296-308.
• 5. Saiz-Ruiz J, Ibanez A, Diaz-Marsa M, Arias F, Padin J, Martin-Carrasco M, Montes JM, Ferrando L, Carrasco JL, Martin-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.
• 6. Shelton C, Entsuah R, Padmanabhan SK, Vinall PE. Venlafaxine XR demonstrates higher rates of sustained remission. Int Clin Psychopharmacol. 2005 Jul;20(4):233-8.
• 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.
• 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.
• 11. Ozyalcin SN, Talu GK, Kiziltan E, Yucel B, Ertas M, Disci R. 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. Venlafaxine in fibromyalgia. Psychosomatics. 1998 Jan-Feb;39(1):14-7
• 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. 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 venlafaxine 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. Neurology. 2003 Apr 22;60(8):1284-9.
• 17. Mukaddes NM, Abali O. Venlafaxine in children and adolescents with attention deficit hyperactivity disorder. Psychiatry Clin Neurosci. 2004 Feb;58(1):92-5.
• 18. Andrews JM, Ninan PT, Nemeroff CB. Venlafaxine: a novel antidepressant that has a dual mechanism of action. Depression. 1996;4(2):48-56.
• 19. Howell C, Wilson AD, Waring WS. Cardiovascular toxicity due to venlafaxine poisoning in adults: 235 consecutive cases. Br J Clin Pharmacol. 2007 Aug;64(2):192-7. PubMedCentral
• 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.