Effexor Dosage: Usual, Maximum And Lethal Doses

Last Updated: December 19, 2019

Authored by Nena Messina, Ph.D.

Venlafaxine Hydrochloride dosage depends on the product form and the formulation – there are immediate-release and extended-release formulations available. Venlafaxine doses are calculated so as there is no need to divide the tablets and capsules, but to take them whole. The Effexor is typically administered in one to two doses during the day, and always with food.

Venlafaxine is only available for oral administration. Venlafaxine dosage is governed by the condition treated, patient tolerability, and observed clinical effects. In addition, patient physiological issues like hepatic or renal impairment may also affect the tolerated dose of Effexor.

Effexor uses are only approved for a prescription to adults. It is not approved for pediatric use, and therefore no pediatric venlafaxine doses are defined.

Effexor Medical Dosage

Venlafaxine dosage depends upon the condition for which the drug is prescribed. Effexor time to work is rapid for each amount of the drug, and it provides critical relief to treat anxiety and depression. Venlafaxine medical amount depends on whether the immediate release or extended-release formulation is used. Effexor XR is the extended-release version of Effexor and has generally shown better outcomes when taken in a stable amount.

Depression Dosage Of Venlafaxine

The starting Venlafaxine dosage for depression is typically 75 mg/day. This Effexor amount is typically administered in two to three divided doses, with meals. Effexor XR is administered once with a meal.

The lowest prescribed Effexor amount typically increased in increments of 75 mg/day, and maintained for at least 4 days. It may be escalated to 150 mg/day once again divided into two or three doses for both formulation types. Patients are typically maintained at this dose for as long as it is medically necessary.

150 mg/day is the most usual venlafaxine dose prescribed. The Effexor maximum dosage should be no greater than 225 mg/day for moderately depressed patients. A maximum amount of 375 mg/day may be used, generally in three divided doses, in some severely depressed patients.

venlafaxine dose for depression

Generalized Anxiety Disorder

To treat generalized anxiety disorder (GAD), Effexor 75mg once a day is used initially. Most patients are maintained on a dose range between 75 and 225 mg/day. 225 mg/day is the highest prescribed amount in GAD patients.

Social Anxiety Disorder

Social anxiety disorder patients only show any benefit with an Effexor dose of 75 mg/day. Higher or lower venlafaxine doses show no modified clinical benefit and are therefore not prescribed.

Panic Disorder

In patients suffering from panic disorder, the lowest prescribed dose of Effexor XR is typically 37.5 mg, which may be escalated to a daily maximum of 225 mg. The typical target venlafaxine amount is 75 mg/day for panic disorder.

Attention Deficit Disorder

In adults with attention deficit disorder, an average Effexor dose of 96 mg/day is recommended to mitigate symptoms. The dosage can vary between 50 and 150 mg/day. This daily amount is typically broken up into two doses to enhance the drug’s effects.

Venlafaxine Doses For Off Label Prescriptions

Effexor may also be prescribed off-label for several conditions, including hot flashes during hormonal chemotherapy, post-traumatic stress disorder, neuropathic pain. The amount of the drug for such conditions usually doesn’t differ a lot from the venlafaxine amount to treat depression and anxiety.

Hot Flashes Due To Hormonal Chemotherapy

The minimum prescribed dose of venlafaxine is 37.5 mg/day to treat hot flashes due to chemotherapy. Patients are typically maintained at 37.5 mg/day for up to one week. The amount may then be escalated to 75 mg/day or even 150 mg/day. This treatment is typically conducted for 4 weeks.

venlafaxine dose for hot flashes

Post-Traumatic Stress Disorder

When the drug is prescribed to treat post-traumatic stress disorder, Effexor XR typically shows better patient outcomes in PTSD patients than its immediate-release counterpart. Venlafaxine dosage is varied between 37.5-300 mg/day to treat PTSD.

Neuropathic Pain

In patients with neuropathic pain, Effexor dosage may be varied between 75-225 mg/day for a maximum period of 6 weeks. However, better clinical outcomes are seen with doses lower than 150 mg/day, and little clinical benefit is seen with escalating the Effexor amount beyond 150mg/day.

Dosage Adjustment For Various Conditions

All doses described here are defined for patients with healthy renal and hepatic systems, as these organs play a significant role in the metabolism of the drug. Therefore, patients suffering from a hepatic or renal impairment would only be able to tolerate lower doses.

Patients with Hepatic Impairment

The recommended total daily dose of venlafaxine should be reduced by 50% for patients with mild to moderate hepatic impairment. In patients with a greater degree of impairment, a reduction of greater than 50% may be required.

venlafaxine Dosage Adjustment

Patients With Renal Impairment

Recommended venlafaxine dosage must be reduced by 25 to 50% for patients with mild to moderate renal impairment. It must be reduced for more than 50% for patients suffering from severe renal impairment or undergoing dialysis.

Missed Doses Of Venlafaxine

A missed dose of Effexor should be taken as soon as the patient remembers. However, if the patient remembers the missed Effexor dose too close to the next one, the patient must wait and take the medication on its regular schedule. Doubling the Effexor must be avoided at all costs. In addition, too many missed doses may precipitate the symptoms of discontinuation syndrome.

Lethal Venlafaxine Dose

Lethal effects are seen at higher venlafaxine doses of less than 2 gm. However, some patients were able to survive after taking the amount as high as 10 gm. Patients who have ingested the highest Effexor doses reported somnolence/coma as the most common symptom. Some patients reported Effexor overdose symptoms like generalized convulsions, prolonged QT intervals (as observed in an electrocardiogram), and sinus tachycardia, which could end tragically without timely intervention.

lethal dose of venlafaxine

Dosage Precautions And Recommendations

There are many severe consequences that may occur if one changes the taken amount of venlafaxine without the doctor’s advice. Here are some more dosage precautions and recommendations:

  • Any dose of venlafaxine and alcohol use must not be combined due to significant side effects and increased lethality.
  • Effexor drug interactions are well documented and must be carefully considered prior to prescription regardless of the prescribed dose.
  • Despite all its benefits, the side effects of Effexor are significant and pronounced regardless of the amount which was taken.
  • If a patient feels that a prescribed amount causes negative reactions, a patient may ask a doctor to consider finding an alternative drug to venlafaxine, for instance, to compare the use of Effexor vs. Lexapro.
  • Effexor must not be discontinued suddenly regardless of the taken amount since venlafaxine withdrawal causes discontinuation syndrome. Instead, the process to stop Effexor must be gradual and conducted under the close supervision of a licensed physician.

If a patient is determined to be addicted to Effexor, it’s recommended to find a suitable rehabilitation center and seek help. Patients would be provided by proper treatment options according to each specific case.

Page Sources

  1. EFFEXOR XR (venlafaxine Extended-Release) Capsules. Highlight Of Prescribing Information. 1997. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020699s107lbl.pdf
  2. Davidson J, Baldwin D, Stein DJ, Kuper E, Benattia I, Ahmed S, Pedersen R, Musgnung J. Treatment of posttraumatic stress disorder with venlafaxine extended release: a 6-month randomized controlled trial. 2006. https://www.ncbi.nlm.nih.gov/pubmed/17015818
  3. Aiyer R, Barkin RL, Bhatia A. Treatment of Neuropathic Pain with Venlafaxine: A Systematic Review. https://www.ncbi.nlm.nih.gov/pubmed/27837032

Published on: November 29th, 2019

Updated on: December 19th, 2019

About Author

Nena Messina, Ph.D.

Nena Messina is a specialist in drug-related domestic violence. She devoted her life to the study of the connection between crime, mental health, and substance abuse. Apart from her work as management at addiction center, Nena regularly takes part in the educational program as a lecturer.


Leave a comment