Venlafaxine: Uses, How to Take, Dosing & Side Effects

Updated in March 2024

Venlafaxine is an antidepressant that is indicated for the treatment of psychological disorders like depression, anxiety or panic syndrome. It acts by inhibiting the reuptake of serotonin and noradrenaline, which are substances responsible for communication between neurons and for the regulation of mood, sleep, appetite, attention and memory.

This medication can be purchased at pharmacies in the form of capsules, and is commonly known by its brand name Effexor XR, or by its generic form with the name "venlafaxine hydrochloride".

Venlafaxine should be used as directed by a doctor. It is only sold and distributed with a signed medical prescription.

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What it's used for

Venlafaxine is indicated for the treatment of:

  • Major depression
  • Generalized anxiety disorder 
  • Social anxiety disorder
  • Panic syndrome, with or without agoraphobia

Venlafaxine belongs to the class of antidepressants that inhibit the reuptake of serotonin and norepinephrine. These are neurotransmitters that play a role in communication between neurons, and are responsible for regulating mood, sleep, appetite, attention and memory.

This medication should always be used as directed by a doctor, who should guide the dose and treatment time, assessing health conditions on an individual basis.

Also recommended: 11 Depression Symptoms (You Shouldn't Ignore)

How to take

Venlafaxine capsules must be taken orally with a meal, always at the time prescribed by the doctor. However, if you forget to take a dose on time, take it as soon as you remember. Only skip the missed dose if it is almost time to take the next dose. Do not double the dose to make up for a forgotten dose.

Recommended dosing

Recommended dosing for adults over 18 years of age varies depending on the indication for use:

  • Depression, generalized anxiety disorder, social anxiety disorder or social phobia: the recommended initial dose is 75 mg per day, which can be increased by the doctor to up to 225 mg per day;
  • Panic syndrome: the recommended initial dose is 37.5 mg per day for 7 days, and after this period it can be increased by the doctor to 75 mg per day or up to a maximum of 225 mg per day.

The onset of action of venlafaxine takes about 3 days after starting treatment, however, it may take up to 4 weeks for treatment to reach a therapeutic effect.

Increasing doses of venlafaxine should be done as directed by the doctor. You should not stop treatment on your own without a doctor's guidance, as the dose of venlafaxine should be reduced slowly to prevent withdrawal symptoms such as anxiety, agitation, nervousness, dizziness, convulsions or increased blood pressure.

Possible side effects

Some of the most common side effects that may occur during treatment with venlafaxine are headache, dizziness, tiredness, weakness, tremors, palpitations, feelings of anxiety or nervousness, weight loss or gain, nausea, vomiting, dry mouth, night sweats , hot flashes, blurred vision, urine retention, decreased sexual desire or impotence.

You should discontinue use and seek medical help immediately or proceed to the nearest emergency room if your notice symptoms of an allergy after taking venlafaxine. This can present as difficulty breathing, feeling of a closed throat, swelling in the mouth, tongue or face, hives or formation of blisters on the skin. Learn ARTICLE NOT FOUND IN EN: identify the symptoms of an allergic reaction.

In addition, the doctor should be informed if the person experiences changes in mood or behavior, anxiety, panic attacks, difficulty sleeping or impulsivity, irritation, agitation, aggression, depression or thoughts about suicide.

Does venlafaxine make you sleepy?

Drowsiness is not a common side effect of venlafaxine. However, this medicine can cause sleepiness when used in doses higher than those recommended, and in this case, other symptoms may also appear such as rapid heartbeat, changes in levels of consciousness, convulsions, vomiting or even coma.

Furthermore, venlafaxine can also cause drowsiness when treatment is stopped suddenly, without a doctor's advice. In this case, anxiety, agitation, nervousness, dizziness, seizures or increased blood pressure may still appear, for example.

Therefore, it is important that the use or interruption of treatment with venlafaxine is carried out under medical supervision.

Contraindications for use

Venlafaxine should not be used by children or adolescents under the age of 18, pregnant or breastfeeding women, people who have uncontrolled glaucoma or who are allergic to venlafaxine or desvenlafaxine.

Furthermore, venlafaxine should not be used by people who take monoamine oxidase inhibitor medications (MAOIs), such as isocarboxazid, phenelzine or tranylcypromine. They should wait at least 14 days after finishing their treatment with MAOIs before starting venlafaxine.

It is important to inform the doctor and pharmacist of all medications or natural products that are used to avoid an increase in the effect of venlafaxine and the appearance of side effects.