Venlafaxine

What it is and how it works

Mechanism of Action The mechanism of the antidepressant action of venlafaxine in humans is believed to be associated with its potentiation of neurotransmitter activity in the CNS. Preclinical studies have shown that venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak inhibitors of dopamine reuptake.

Indications

Venlafaxine extended-release tablets are a selective serotonin and norepinephrine reuptake inhibitor (SNRI) indicated for: Major Depressive Disorder (MDD) Social Anxiety Disorder (SAD) Major Depressive Disorder Venlafaxine extended-release tablets are indicated for the treatment of major depressive disorder (MDD). Efficacy of venlafaxine in MDD was shown in both short-term trials and a longer-term trial in MDD [ see Clinical Studies ]. A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed mood or the loss of interest or pleasure in nearly all activities, representing a change from previous functioning, and includes the presence of at least five of the following nine symptoms during the same two-week period: depressed mood, markedly diminished interest or pleasure in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, a suicide attempt or…

Dosage and administration (summary)

Venlafaxine extended-release tablets should be administered in a single dose with food either in the morning or in the evening at approximately the same time each day. Each tablet should be swallowed whole with fluid and not divided, crushed, chewed, or placed in water. Initial Treatment Indication Starting Dose Dose Increase Maximum Dose Major Depressive Disorder 75 mg/day (in some patients, 37.5 mg/day for 4-7 days) 75 mg/day increments at intervals of 4 days or longer 225 mg/day Social Anxiety Disorder 75 mg/day No benefit at higher doses 75 mg/day Venlafaxine extended-release tablets should be taken as a single daily dose with food in either the morning or evening at the same time each d…

Contraindications

Serotonin Syndrome and MAOIs: Do not use MAOI’s intended to treat psychiatric disorders with venlafaxine extended-release tablets or within 7 days of stopping treatment with venlafaxine extended-release tablets. Do not use venlafaxine extended-release tablets within 14 days of stopping an MAOI intended to treat psychiatric disorders. In addition, do not start venlafaxine extended-release tablets in a patient who is being treated with linezolid or intravenous methylene blue.

Warnings and precautions

Serotonin Syndrome : Serotonin syndrome has been reported with SSRIs and SNRIs, including venlafaxine extended-release tablets, both when taken alone, but especially when co-administered with other serotonergic agents. If such symptoms occur, discontinue venlafaxine extended-release tablets and serotonergic agents and initiate supportive treatment.

Pregnancy

Pregnancy Based on data from published observational studies, exposure to SNRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage .

Storage and supply

Venlafaxine extended-release tablets 37.5 mg are white to off white, beveled edge, round biconvex, film coated tablets with release port on one side and imprinted ‘V1’ with black ink on any side.

Source: Venlafaxine (Venlafaxine Hydrochloride) — US FDA prescribing information, 2025-04-03, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.