Venlafaxine (brand name Effexor) is a serotonin–norepinephrine reuptake inhibitor (SNRI) antidepressant used to treat major depressive disorder (MDD) and several anxiety disorders. [1] Venlafaxine is available in immediate-release (IR) and extended-release (XR) formulations. [2]
The actual dosage for each patient depends on the condition treated and other factors such as additional medications. Always follow your doctor’s instructions and discuss any dose changes with them.
- Start low and increase gradually. Typical starting doses are 37.5–75 mg/day, with the usual adult target around 150 mg/day.
- Venlafaxine comes as IR tablets (taken 2–3 times daily) and XR capsules (taken once daily). It should be taken with food at the same time each day to reduce nausea.
- Monitor adverse effects and blood pressure increases. Do not stop suddenly – taper the dose slowly under medical supervision to avoid withdrawal symptoms.
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Venlafaxine (Effexor) dosage overview
Venlafaxine is approved by the US Food and Drug Administration (FDA) to treat major depression and several anxiety disorders: generalized anxiety disorder, social anxiety disorder, and panic disorder. [2] It helps boost levels of serotonin and norepinephrine — two brain chemicals that affect mood and anxiety.
Venlafaxine should be taken at the same time daily; setting a phone reminder or alarm can help maintain consistency. The XR capsules must be swallowed whole. [4] The IR tablets may be taken 2–3 times per day with meals.
Venlafaxine usually takes 4–6 weeks for full effect, though some improvement may appear after 1–2 weeks. [3] Typical treatment is long-term (months). You may need to take venlafaxine for 6–12 months or longer, depending on your condition and response. [3]
It’s important to keep taking the medication as prescribed during this time. Monitoring mood changes or side effects and keeping a daily record can help track how well you respond to treatment. Your doctor will decide how long you should stay on venlafaxine; do not discontinue on your own. [3]
Venlafaxine forms: IR vs. XR
Venlafaxine is sold as immediate-release (IR) tablets and extended-release (XR) capsules. Effexor (IR) tablets are taken multiple times per day, while Effexor XR capsules are taken once daily. [4] One guideline suggests that for depression, the IR venlafaxine dosage might be 75 mg per day divided into 2–3 doses (e.g., 25 mg three times daily). [2] In contrast, the XR form often starts at 75 mg once daily. [2]Â
The XR formulation releases medication over time, so it maintains steadier blood levels with one daily dose. The IR tablets absorb faster and require more frequent dosing.
Starting dose and titration guide
Major Depressive Disorder (MDD)
The usual starting dose of Effexor XR is 75 mg once daily. Some patients begin at 37.5 mg once daily for 4–7 days and then increase to 75 mg to ease into the medication. [2][4] If needed, the dose can be raised gradually by 75 mg increments (no more than every 4–7 days) up to a typical maximum of 225 mg/day for outpatients. [5]Â
For venlafaxine IR tablets, one option is starting at 37.5 mg twice daily (or 25 mg three times daily), with maintenance around 75–150 mg/day (split doses) and a maximum of 225 mg/day. [2][3]
Generalized Anxiety Disorder (GAD)
Dosing for GAD is similar to that for depression. Effexor XR is usually 75 mg once daily initially. Some patients again start at 37.5 mg for 4–7 days before raising to 75 mg. The dose may be increased as needed (roughly 75 mg weekly) up to 225 mg/day. [5]
Social Anxiety Disorder (Social Phobia)
The recommended dose is 75 mg once daily (XR). Studies show no additional benefit from higher doses in social anxiety. [5] Thus, 75 mg is both the starting and maximum effective dose for this condition.
Panic Disorder
Start Effexor XR at 37.5 mg once daily for one week, then increase to 75 mg once daily. If needed, raise the dose in 75 mg steps (about weekly) up to 225 mg/day. [5] The total daily dose can be taken as a single daily XR dose or split into two IR doses.
Doctors monitor response during titration, increasing doses no more than weekly—or more slowly if you're sensitive. [5] Always use the lowest effective dose.
Maximum dose
For most conditions, 225 mg/day is the recommended upper limit (outpatients). [5] Doses above this (up to 375 mg) were used in severe cases in clinical trials, but higher doses carry more side effects.
Special considerations for special populations
- Hepatic (liver) impairment: People with liver problems clear venlafaxine from their bodies more slowly, so they may need a lower dose. [5]
- Renal impairment: For patients with reduced kidney function, dose adjustments are also advised. [5]
- Elderly: Older adults may be more sensitive to venlafaxine’s effects (dizziness, blood pressure changes). [5]
- Pregnancy/Breastfeeding: Use with caution; discuss risks/benefits with a physician.
- Children: Venlafaxine is not approved for children under 18 for depression or anxiety; use in minors is advised only under specialist supervision.
Therapy should be supervised by a healthcare provider in all cases, but especially so in these special populations. Inform your doctor of any kidney, liver, heart, or other medical issues so they can adjust dosing. [5]
Side effects and how to manage them
Most people tolerate venlafaxine well, but it’s common to have some side effects when you first start or increase the dose. Many people have no or only mild side effects, and these often improve as the body adjusts. [6]Â
The most common side effects include: [6]
- Nausea—eating a small snack with your medication might reduce discomfort.
- Dry mouth
- Headache
- Fatigue or somnolence
- Insomnia
- Sweating
Other reported side effects include: [6]
- Dizziness
- Constipation
- Nervousness
- Loss of appetite
- Weight changes
- Sexual side effects (decreased libido or erectile dysfunction)
Venlafaxine boosts norepinephrine at higher doses, meaning it can also raise blood pressure. This is dose-related and should be monitored (especially above 150 mg). [7]
What to do if you experience side effects
If side effects occur:
- Do not stop taking the medication suddenly.
- Consult your doctor.
Emergency symptoms
If you get severe reactions such as chest pain, severe dizziness or fainting, fast or irregular heartbeat, or any signs of an allergic reaction (rash, swelling), seek emergency care. Also, report any new or worsening depression or suicidal thoughts immediately (venlafaxine carries a black box warning about increased risk of suicidal thoughts, especially when starting or changing dose).
Venlafaxine interactions and overdose
Certain medications must not be combined with venlafaxine, like:
- Monoamine oxidase inhibitors [5]
- Other SSRIs/SNRIs, triptans, certain migraine medications, and St. John’s Wort can increase the risk of serotonin syndrome
- NSAIDs or blood thinners (like warfarin) may increase bleeding risk
Overdose
An overdose of venlafaxine can be life-threatening. Common acute signs may include: [8]
- Extreme drowsiness
- Agitation
- Tremors
- Fast heartbeat
- Mild high blood pressure
- Serotonin syndrome.
Symptoms of severe overdose include: [8]
- Cardiac arrhythmias (heart rhythm problems)
- Prolonged QT interval of the heart
- Seizures
- Alterations in consciousness
Large overdoses may require emergency treatment like activated charcoal or cardiac monitoring. Even a few grams can be dangerous. If overdose is suspected, seek immediate medical help. [8]
Stopping venlafaxine: Tapering and withdrawal management
Venlafaxine has a relatively short half-life (about 5–13 hours). [5] This means its levels drop quickly if doses are missed or stopped, leading to withdrawal (discontinuation) symptoms.
Venlafaxine must be tapered gradually to minimize withdrawal. Doctors generally recommend reducing the dose slowly over weeks rather than stopping suddenly. For example, one strategy is to lower the daily dose by about 37.5–75 mg each week until complete (as shown in patient guidelines). [5]
The Effexor XR prescribing information suggests tapering by 75 mg per week. Depending on your starting dose and sensitivity, a typical taper schedule might take 2–4 weeks (or longer). [5]
Management
If you have withdrawal symptoms, contact your doctor. They may slow down the taper or temporarily raise the dose again. Stopping venlafaxine on your own is not advised.
Special note
Because venlafaxine withdrawal can be unpleasant, some clinicians switch patients to a longer-acting SSRI like fluoxetine (Prozac) before tapering, or simply take smaller and smaller steps.
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