Venlafaxine
An SNRI used for depression, generalized and social anxiety disorder, and panic disorder.
Drug card
- Class
- SNRI
- How it works
- Blocking reuptake of both serotonin and norepinephrine
- Used for
- Depression
- Generalized and social anxiety disorder
- Panic disorder
- Known for
- Raised blood pressure, rising with the dose
- Discontinuation symptoms if stopped suddenly
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does venlafaxine work?
Venlafaxine potently blocks serotonin and norepinephrine reuptake and weakly blocks dopamine reuptake, and so does its active metabolite, O-desmethylvenlafaxine (desvenlafaxine). Neither has significant affinity for muscarinic, H1-histamine or α1-adrenergic receptors.
Like other serotonin-norepinephrine reuptake inhibitors: SNRIs block both the serotonin transporter (SERT) and the norepinephrine transporter (NET), so both transmitters stay longer in the synapse. The added norepinephrine effect is thought to help with nerve pain, and it can also push blood pressure up. Like SSRIs, they have no significant affinity for muscarinic, histamine or α1 receptors, so they lack the sedating and anticholinergic burden of tricyclics.
Uses
What is venlafaxine used for?
- Depression
- Generalized and social anxiety disorder
- Panic disorder
Side effects
Side effects of venlafaxine
- Raised blood pressure, rising with the doseKnown forSerious
- Discontinuation symptoms if stopped suddenlyKnown for
- Nausea
- Drowsiness
- Dry mouth
- Heavy sweating
- Loss of appetite
- Constipation
- Abnormal ejaculation, impotence and low libido
- Serotonin syndromeSerious
- Suicidal thoughts in children and young adultsSerious
- Low sodium (hyponatremia)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Control high blood pressure before starting and check it regularly, since increases are dose-related.
- Leave 7 days after stopping venlafaxine before an MAOI, and 14 days after an MAOI before venlafaxine.
- Taper gradually when stopping to limit discontinuation symptoms.
Good to know: Its blood pressure rise is dose-related, and its active metabolite desvenlafaxine shares its effects; people allergic to desvenlafaxine should not take it.
Remember it
A way to remember it
The extra N brings nerve-pain relief and a blood pressure check.
Blocking norepinephrine reuptake as well as serotonin is why duloxetine treats diabetic nerve pain and fibromyalgia, and why SNRIs can raise blood pressure, which is measured before and during treatment.
Written for biofideX
Its class
Serotonin-norepinephrine reuptake inhibitors
Other serotonin-norepinephrine reuptake inhibitors with a card:
Easily mixed up with selective serotonin reuptake inhibitors and tricyclic antidepressants.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Venlafaxine hydrochloride extended-release capsules: label (DailyMed)
- Venlafaxine (NCI Thesaurus)
- Venlafaxine (NHS)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Depression, anxiety and sleep
Venlafaxine is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
Start Practicing