This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Venlafaxine oral standard release

Updated 2 Feb 2023 | Other antidepressants


Standard release oral formulations of venlafaxine.

Drugs List

  • venlafaxine 37.5mg tablets
  • venlafaxine 37.5mg/5ml oral solution sugar-free
  • venlafaxine 75mg tablets
  • venlafaxine 75mg/5ml oral solution sugar-free
  • Therapeutic Indications


    Prevention of relapse or recurrence of depressive illness
    Treatment of depressive illness


    Treatment should be reassessed regularly on a case-by-case basis, taking into consideration the risk of relapse or recurrence of symptoms.

    Dose increases should be made at 2 week intervals or more. In severe cases, doses may be increased more frequently but not less than every 4 days.

    Antidepressive treatment should continue for at least six months following remission.


    37.5mg twice daily.
    If initial response is poor, consider increasing the dose as needed to a maximum of 375mg daily.

    Patients with Renal Impairment

    Severe renal impairment (GFR less than 30 ml/minute) and patients requiring haemodialysis: reduce dose by 50%.

    Patients with Hepatic Impairment

    In mild to moderate hepatic impairment a dose reduction of 50% should be considered.

    Caution in severe hepatic impairment, a dose reduction of greater than 50% should be considered.

    Additional Dosage Information

    Switching from immediate release preparations
    Patients treated with venlafaxine immediate release preparations may be switched to venlafaxine modified release preparations at the nearest equivalent daily dosage. Individual dosage adjustments may be necessary.


    Children under 18 years
    Within 2 weeks of discontinuing MAOIs
    Long QT syndrome
    Torsade de pointes
    Uncontrolled hypertension

    Precautions and Warnings

    Family history of bipolar disorder
    Family history of long QT syndrome
    Patients under 25 years
    Predisposition to haemorrhage
    Predisposition to narrow angle glaucoma
    Suicidal ideation
    Bipolar disorder
    Diabetes mellitus
    Electrolyte imbalance
    Epileptic disorder
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Hereditary fructose intolerance
    History of mania
    History of seizures
    History of torsade de pointes
    Intraocular hypertension
    Lactose intolerance
    Recent myocardial infarction
    Renal impairment - glomerular filtration rate below 30ml/minute
    Serious cardiac arrhythmias
    Unstable cardiac disorder

    Adjustment of hypoglycaemic therapy may be necessary in diabetes mellitus
    Correct electrolyte disorders before treatment
    Patients at risk of suicide should be closely supervised
    Reduce dose in patients with hepatic impairment
    Reduce dose in patients with severe renal impairment
    Advise patient ability to drive or operate machinery may be impaired
    Oral solution contains parabens: Potential for delayed allergic reactions
    Oral solution with maltitol unsuitable in hereditary fructose intolerance
    Some formulations contain lactose
    Consider monitoring ECG in patients at risk of QT prolongation
    Discontinue treatment if patient develops seizures
    May cause hyponatraemia
    Monitor cholesterol and triglyceride levels
    Monitor heart rate and blood pressure regularly
    Monitor patient closely during titration of dose
    Monitor patients at risk of glaucoma for increases in intraocular pressure
    Monitor patients for adverse reactions including restlessness & agitation
    Monitor patients for signs and symptoms of Serotonin Syndrome
    Monitor serum electrolytes
    When used with SSRIs, risk of Serotonin syndrome
    Aggressive behaviour may occur
    Consider dose reduction or discontinuation if serotonin syndrome suspected
    Decreased salivary secretions may lead to dental caries
    Do not increase dosage in patients who develop akathisia
    Potential for increased risk of bleeding
    Potential for withdrawal symptoms
    May affect results of some laboratory tests
    Avoid MAOIs for 7 days after discontinuing this drug
    To discontinue, reduce dose gradually
    Maintain treatment at the lowest effective dose
    Advise patient not to take St John's wort concurrently
    Advise patient to avoid alcohol during treatment
    Advise patient on need for adequate dental hygiene & regular dental checks
    Advise patient/carers to report signs of suicide ideation or behaviour

    Close supervision is advised in all patients, in particular those at high risk, during early treatment and following dose changes.

    Depression is associated with an increased risk of suicidal thoughts, self harm and suicide (suicide related events). This risk persists until significant remission occurs. As improvement may not occur during the first few weeks or more of treatment, patients should be closely monitored until such improvement occurs. It is general clinical experience that the risk of self harm is highest shortly after presentation and the risk of suicide may increase again in the early stages of recovery. Furthermore, there is evidence that in children, adolescents and adult under 25 years, antidepressants may increase the risk of suicidal thoughts and self harm.

    Other psychiatric conditions for which venlafaxine is prescribed can also be associated with an increased risk of suicide related events. In addition, these conditions may be co-morbid with major depressive disorder. The same precautions observed when treating patients with major depressive disorder should therefore be observed when treating patients with other psychiatric disorders.

    Patients with a history of suicide related events, those exhibiting a significant degree of suicidal ideation prior to commencement of treatment, and young adults, are at a greater risk of suicidal thought or suicide attempt, and should receive careful monitoring during treatment.

    Increases in heart rate can occur, particularly at high doses. Caution should be exercised in patients whose underlying conditions might be compromised by increased heart rate.

    Serotonin-norepinephrine reuptake inhibitors may cause symptoms of sexual dysfunction. There have been reports of long-lasting sexual dysfunction where the symptoms have continued despite their discontinuation.

    Pregnancy and Lactation


    Use venlafaxine with caution during pregnancy.

    The manufacturer does not recommend using venlafaxine during pregnancy and that venlafaxine must only be administered to pregnant women if the expected benefits outweigh any possible risk. Animal studies have shown teratogenic effects, however human data is limited. Whilst the limited human data has shown no evidence of structural anomalies, developmental toxicity including spontaneous abortions, low birth weight, premature birth, neonatal serotonin syndrome, neonatal behavioural syndrome (withdrawal including seizures) and respiratory distress have been reported.

    Persistent pulmonary hypertension (PPHN) in the newborn is also a potential risk. Whilst a link to venlafaxine has not been investigated, epidemiological data suggests an increased risk of PPHN following use of selective serotonin re-uptake inhibitors (SNRIs), particularly during late pregnancy. Due to their similar mechanism of action, a risk with venlafaxine cannot be ruled out. SNRIs may also increase the risk of postpartum haemorrhage within the month prior to birth.

    Use of venlafaxine up until or shortly before birth can cause withdrawal effects or adaptation problems in the neonate. In the majority of cases, symptoms arise within 24 hours of delivery and include irritability, tremor, hypotonia, persistent crying, and difficulty in sucking or in sleeping. Complications requiring tube-feeding, respiratory support or prolonged hospitalisation have also been reported. There is an increased risk of postpartum haemorrhage following SNRIs exposure within the month prior to birth.

    In patients established on venlafaxine prior to becoming pregnant, abrupt discontinuation should be avoided as this carries a higher risk of relapse. Ongoing management should balance potential risk to the foetus with potential risk to maternal health if treatment is discontinued/changed. Venlafaxine may be continued with caution in those at a significant risk of relapse. When managing new episodes of depression or anxiety during pregnancy, consider the use of psychological therapy where possible. Whilst no antidepressant is considered safe during pregnancy, alternative options with greater experience may be preferable.


    Venlafaxine is contraindicated in breastfeeding.

    The manufacturer advises that the patient either discontinues venlafaxine or discontinues breastfeeding.

    Venlafaxine and its active metabolite, O-desmethylvenlafaxine are excreted in human breast milk. There are reports of nursing infants experiencing crying, irritability and abnormal sleep patterns. Breastfed infants, especially newborn or preterm infants, should be monitored for excessive sedation and adequate weight gain if this drug is used during lactation (LactMed, 2022). Discontinuation symptoms have been reported after stopping breastfeeding.

    Briggs (2015) notes that venlafaxine provides a relatively high infant dose compared to other antidepressants and that long-term effects on neurobehaviour and cognitive development have not been adequately studied. If used, the infant should be monitored for short-term adverse effects. Schaefer (2015) concludes that venlafaxine is tolerable if compellingly indicated, but that whenever possible, drugs of choice among the tricyclic antidepressants or selective serotonin re-uptake inhibitors should be used in preference.

    Side Effects

    Abnormal ejaculation
    Abnormal liver function tests
    Aplastic anaemia
    Blood dyscrasias
    Decreased appetite
    Disturbances in accommodation
    Dream abnormalities
    Dry mouth
    Erectile dysfunction
    Erythema multiforme
    Extrapyramidal effects
    Gastro-intestinal haemorrhage
    Glaucoma (closed angle)
    Hot flushes
    Impaired co-ordination
    Impaired urination
    Inappropriate secretion of antidiuretic hormone
    Increase in muscle tone
    Increase in serum cholesterol (transient)
    Increased prolactin
    Menstrual disturbances
    Mucous membrane bleeding
    Neuroleptic malignant syndrome
    Night sweats
    Orgasmic dysfunction
    Postural hypotension
    Prolongation of QT interval
    Prolonged bleeding
    Psychomotor restlessness
    Pulmonary eosinophilia
    Reduced libido
    Serotonin syndrome
    Stevens-Johnson syndrome
    Suicidal tendencies
    Tardive dyskinesia
    Taste disturbances
    Torsades de pointes
    Toxic epidermal necrolysis
    Urinary retention
    Ventricular fibrillation
    Ventricular tachycardia
    Visual disturbances
    Weight changes

    Effects on Laboratory Tests

    Venlafaxine may affect immunoassay screening tests for phencyclidine (PCP) and amphetamine producing false-positive results. This can be expected for several days after discontinuing venlafaxine. Confirmatory tests such as gas chromatograph/mass spectrometry can be used to distinguish venlafaxine from PCP and amphetamine.

    Withdrawal Symptoms and Signs

    Discontinuation of venlafaxine commonly leads to withdrawal symptoms such as: dizziness, sensory disturbances (including paraesthesia), sleep disturbances (including insomnia and intense dreams), agitation and anxiety, nausea and/or vomiting, tremor, vertigo, headache and flu syndrome.

    When discontinuing venlafaxine, gradually reduce the dose over at least one to two weeks and monitor to minimise the risk of withdrawal reactions. The period required for discontinuation may depend on the dose, duration of therapy and the individual patient. In some patients, discontinuation may need to occur very gradually over periods of months or longer.

    If intolerable symptoms occur resume previous prescribed dose. Subsequently, continue decreasing the dose at a more gradual rate.


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: September 2022

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Summary of Product Characteristics: Venlafaxine 37.5mg/5ml Oral Solution. Rosemont Pharmaceuticals Limited. Revised July 2021.
    Summary of Product Characteristics: Venlafaxine 75mg/5ml Oral Solution. Rosemont Pharmaceuticals Limited. Revised July 2021.

    Summary of Product Characteristics: Venlafaxine 37.5mg tablets. Dexcel Pharma Ltd. Revised July 2021.
    Summary of Product Characteristics: Venlafaxine 75mg tablets. Dexcel Pharma Ltd. Revised July 2021.

    Summary of Product Characteristics: Venlafaxine 37.5mg tablets. Teva Pharma Ltd. Revised December 2021.
    Summary of Product Characteristics: Venlafaxine 75mg tablets. Teva Pharma Ltd. Revised December 2021.

    MHRA Drug Safety Update January 2021 Available at: Last accessed: 11 February 2021

    NICE Evidence Services Available at: Last accessed: 28 September 2022

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Venlafaxine. Last revised: 19 September 2022
    Last accessed: 28 September 2022

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.