Buy Venlafaxine (Effexor) Cas 93413-69-5

Venlafaxine, sold under the brand name Effexor among others, is an antidepressant medication of the serotonin–norepinephrine reuptake inhibitor (SNRI) class.^[5][9] It is used to treat major depressive disorder, generalized anxiety disorder, panic disorder, and social anxiety disorder.^[9] Studies have shown that venlafaxine improves post-traumatic stress disorder (PTSD) as a recommended first-line treatment.^[10] It may also be used for chronic neuropathic pain.^[11] It is taken orally (swallowed by mouth).^[9] It is also available as the salt venlafaxine besylate (venlafaxine benzenesulfonate monohydrate) in an extended-release formulation (Venbysi XR).^[6]

Common side effects include loss of appetite, constipation, dry mouth, dizziness, sweating, insomnia, drowsiness and sexual problems.^[9] Severe side effects include an increased risk of suicide, mania, and serotonin syndrome.^[9] Antidepressant withdrawal syndrome may occur if stopped.^[9] A meta-analysis of randomized trials in depression found an increased rate of serious adverse events, particularly sexual dysfunction and anorexia, and several non-serious adverse effects, including nervousness, asthenia, and tremor.^[12] There are concerns that use during the later part of pregnancy can harm the baby.^[9] Venlafaxine’s mechanism of action is not entirely clear, but it seems to be related to the potentiation of the activity of some neurotransmitters in the brain.^[9]

Venlafaxine was approved for medical use in the United States in 1993.^[9] It is available as a generic medication.^[9] In 2023, it was the 51st most commonly prescribed medication in the United States, with more than 13 million prescriptions.^[13][14]

Venlafaxine is used primarily for the treatment of depression, general anxiety disorder, social phobia, panic disorder, and vasomotor symptoms.^[15]

Concerns that noradrenergic reuptake might precipitate anxiety have not been borne out in randomized trials: a 2016 systematic review of 52 double-blind, placebo-controlled studies (mostly with venlafaxine or duloxetine) found clinically significant improvements in anxiety symptoms and no signal for treatment-emergent anxiety attributable to SNRIs.^[16]

Venlafaxine has been used off label for the treatment of diabetic neuropathy^[17] and migraine prevention.^[18] It may work on pain via effects on the opioid receptor.^[19] It has also been found to reduce the severity of ‘hot flashes’ in menopausal women and men on hormonal therapy for the treatment of prostate cancer.^[20][21]

Due to its action on both the serotonergic and adrenergic systems, venlafaxine is also used as a treatment to reduce episodes of cataplexy, a form of muscle weakness, in patients with the sleep disorder narcolepsy.^[22] Some open-label and three double-blind studies have suggested the efficacy of venlafaxine in the treatment of attention deficit-hyperactivity disorder (ADHD).^[23] Clinical trials have found possible efficacy in those with post-traumatic stress disorder (PTSD).^[24] Case reports, open trials and blinded comparisons with established medications have suggested the efficacy of venlafaxine in the treatment of obsessive–compulsive disorder.^[25]

A comparative meta-analysis of 21 major antidepressants found that venlafaxine, agomelatine, amitriptyline, escitalopram, mirtazapine, paroxetine, and vortioxetine were more effective than other antidepressants, although the quality of many comparisons was assessed as low or very low.^[26][27]

Open-label evidence also suggests potential benefit in treatment-resistant cases: in a multicenter Canadian study of adults with inadequate response to prior antidepressants (n=159), 58% achieved response and 28% remission after 8 weeks of venlafaxine (mean 260 mg/day); tolerability was generally acceptable.^[28]