Venlafaxine

Venlafaxine, sold under the brand name Effexor among others, is an antidepressant of the serotonin-norepinephrine reuptake inhibitor class.

Venlafaxine

Venlafaxine; Elafax; Effexor; Venlafaxinum

Dalium, Envelaf-XR, Faxiven-XR, Flavix, Sentosa, Velaf-ER, Ven-OD, Venaxin, Vendep XR, Venfax-PR, Veniz-XR, Venjoy-XR, Venla, Venlamax, Venlift, Venlift-Od, Venlor, Venlor-XR, Venrea, Vexor, Vlx, Vlx-XR

1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl]cyclohexan-1-ol

Well absorbed from the GI tract, hepatic metabolism.

Venlafaxine potentiates the neurotransmitter activity in the central nervous system. Venlafaxine and its metabolite, ODV (O-desmethylvenlafaxine) inhibit the reuptake of serotonin and norepinephrine potently and weakly inhibit dopamine reuptake. Both molecules do not bind to histaminergic, muscarinic, or alpha-1 adrenergic receptors. 

Oral

For the management of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (social phobia), panic disorder with or without agoraphobia, vasomotor symptoms in women with breast cancer and in postmenopausal women, and neuropathic pain.

Blood dyscrasias, Stevens-Johnson syndrome, hepatitis. Nausea, vomiting, anorexia, dry mouth, constipation, orthostatic hypotension, tremour, sweating, rash, anxiety, dizziness, fatigue, headache, syncope, insomnia, somnolence, constipation, hyponatraemia, sexual dysfunction, dyspepsia, visual disturbances, mydriasis, increased cholesterol concentrations, increased LFT.

• Increased risk of serotonin syndrome with MAOI, do not use within at least 14 days of discontinuing MAOI treatment and start MAOI at least 7 days after stopping venlafaxine.
• Increased risk of serotonin syndrome with sibutramine.
• Risk of serotonin syndrome with triptans, linezolid, lithium, tramadol.
• Increased risk of anticholinergic side effects and serotonin syndrome with TCA, SSRI.
• Decreased indinavir concentration with concurrent use.
• Increased INR with warfarin.
• Increase risk of serotonin syndrome with St John's Wort and jujube (suanzaoren, Ziziphus jujuba).
• Possible risk of serotonin syndrome with metoclopramide, and amoxicillin with clavulanate combinations.

Lactation. Uncontrolled hypertension; high risk of serious ventricular arrhythmia.

Store below 30°C

Molecular weight

277.4018

Molecular formula

C17H27NO2

CAS number

93413-69-5

Precautions

• Moderate to severe renal or hepatic impairment.
• Conditions which may be worsened by increase in heart rate.
• History of MI, bleeding disorder, epilepsy, hypomania or mania.
• Raised intraocular pressure or risk at angle-closure glaucoma.
• May impair performance of skilled tasks, driving or machinery operation. Monitor BP and serum cholesterol regularly.
•  Monitor closely during early therapy until depression improves due to increased risk of suicide.
• Avoid abrupt withdrawal.
• Withdraw gradually over at least 1-2 weeks and monitor for withdrawal symptoms e.g. fatigue, headache, nausea, vomiting, palpitations.
• Discontinue if seizure develops or increase in seizure frequency. Elderly, pregnancy.