Edronax (Reboxetine)
Selective Norepinephrine Reuptake Inhibitor for Major Depression
Quick Facts About Edronax
Key Takeaways About Edronax
- Unique noradrenergic mechanism: Edronax selectively targets norepinephrine reuptake, making it distinct from SSRIs and potentially beneficial for patients with fatigue, low motivation, and poor concentration
- Twice-daily dosing: The standard dose is 4 mg twice daily (morning and evening), which may be increased to a maximum of 12 mg per day based on clinical response
- Watch for urinary symptoms: Reboxetine can cause difficulty urinating, especially in men with prostate enlargement – report any urinary problems to your doctor promptly
- Serotonin syndrome risk: Combining Edronax with other serotonergic or noradrenergic drugs (MAO inhibitors, SSRIs, triptans) can cause potentially life-threatening serotonin syndrome
- Do not stop abruptly: Gradual dose reduction is recommended when discontinuing Edronax to avoid withdrawal symptoms including headache, dizziness, and nausea
What Is Edronax and What Is It Used For?
Edronax (reboxetine) is an antidepressant belonging to the selective norepinephrine reuptake inhibitor (NRI) class. It is used for the acute treatment of major depressive disorder and for maintenance therapy to prevent relapse in adults who have initially responded to treatment.
Edronax contains the active ingredient reboxetine, which works by selectively blocking the reuptake of norepinephrine (also called noradrenaline) at the nerve synapse. By preventing norepinephrine from being reabsorbed back into the nerve cell, reboxetine increases the amount of this neurotransmitter available in the brain. Norepinephrine plays a crucial role in regulating mood, alertness, energy, motivation, and concentration – functions that are often impaired in people with depression.
Unlike selective serotonin reuptake inhibitors (SSRIs), which primarily target serotonin, reboxetine has minimal effect on serotonin reuptake. This unique pharmacological profile means that Edronax may be particularly beneficial for patients whose depression is characterised by symptoms of noradrenergic dysfunction, such as persistent fatigue, lack of motivation, difficulty concentrating, psychomotor retardation, and social withdrawal. Clinical studies have suggested that reboxetine may improve social functioning and motivation more than some SSRIs in certain patient populations.
Edronax is indicated for two main purposes. First, it is used for acute treatment of depressive episodes, where the goal is to achieve remission of symptoms such as low mood, loss of interest, sleep disturbances, appetite changes, and cognitive difficulties. Second, it is used for maintenance therapy to sustain the clinical improvement achieved during acute treatment and to prevent the return of depressive symptoms. International treatment guidelines generally recommend continuing antidepressant treatment for at least 6 to 12 months after achieving remission to reduce the risk of relapse.
Reboxetine was first authorised for medical use in Europe in 1997 and has since been available in numerous countries worldwide. It is marketed primarily under the brand name Edronax, manufactured by Pfizer. While it is less commonly prescribed than SSRIs, it remains an important treatment option for patients who do not respond to or cannot tolerate serotonergic antidepressants.
Depression is one of the leading causes of disability worldwide, affecting an estimated 280 million people globally according to the World Health Organization (WHO). Multiple neurotransmitter systems – including serotonin, norepinephrine, and dopamine – are involved in the pathophysiology of depression. Having treatment options that target different neurotransmitter pathways, such as Edronax, is important for personalising treatment to individual patient needs.
What Should You Know Before Taking Edronax?
Before starting Edronax, inform your doctor about all your medical conditions, particularly seizure disorders, urinary problems, prostate enlargement, glaucoma, heart disease, or liver and kidney impairment. Tell your doctor about all medications you are taking, especially MAO inhibitors and other antidepressants.
Contraindications
You should not take Edronax if the following applies to you:
- Allergy to reboxetine or any of the other ingredients in Edronax – symptoms of an allergic reaction may include skin rash, itching, swelling, or difficulty breathing
If you have previously experienced an allergic reaction to reboxetine or to any tablet excipient (including microcrystalline cellulose, dibasic calcium phosphate dihydrate, crospovidone, colloidal anhydrous silica, or magnesium stearate), you must not take Edronax. Seek immediate medical attention if you suspect an allergic reaction.
Warnings and Precautions
Talk to your doctor or pharmacist before taking Edronax if you have or have had any of the following conditions:
- Seizure disorder or epilepsy – Edronax should be discontinued if seizures occur during treatment. Antidepressants may lower the seizure threshold in susceptible individuals
- Urinary tract problems or prostate enlargement – reboxetine can cause difficulty urinating, urinary retention, or a feeling of incomplete bladder emptying. This is more common in men with benign prostatic hyperplasia
- Heart disease or cardiovascular problems – reboxetine may cause increased heart rate, palpitations, or changes in blood pressure. Patients with pre-existing cardiovascular conditions require careful monitoring
- Low blood pressure or taking blood pressure-lowering medications – reboxetine can cause orthostatic hypotension (a drop in blood pressure upon standing), which may increase the risk of falls
- Liver or kidney impairment – the starting dose may need to be reduced in patients with hepatic or renal insufficiency, as clearance of the drug is reduced
- Previous history of mania – antidepressants may trigger manic episodes in susceptible individuals, particularly those with bipolar disorder
- Glaucoma (particularly narrow-angle glaucoma) – reboxetine may increase intraocular pressure in some patients
- Current or recent use of MAO inhibitors – at least two weeks must elapse between stopping an MAO inhibitor and starting Edronax, due to the risk of serious interactions
Serotonin syndrome is a potentially life-threatening condition that can occur when taking Edronax alone or in combination with other serotonergic or noradrenergic medications. Symptoms may include a combination of: confusion, agitation, hallucinations, coma, rapid heartbeat, elevated body temperature, rapid blood pressure changes, sweating, flushing, tremor, hyperreflexia, nausea, vomiting, and diarrhoea. Seek immediate medical attention if you experience these symptoms.
Suicidal Thoughts and Behaviour
If you are depressed and/or suffer from anxiety, you may sometimes have thoughts of harming yourself or committing suicide. These thoughts may increase when you first start taking antidepressants, because these medicines take time to work – usually about two weeks or sometimes longer before the full therapeutic effect is achieved.
You may be more likely to experience these thoughts if you:
- Have previously had thoughts of harming yourself or committing suicide
- Are a young adult under the age of 25 – clinical data has shown that young adults with psychiatric conditions treated with antidepressants have an increased risk of suicidal thinking and self-harming behaviour
Contact your doctor or go to the nearest hospital immediately if you have any thoughts of self-harm or suicide at any time during treatment. It may be helpful to tell a relative or close friend that you are being treated for depression, and ask them to read this information. You may also ask them to tell you if they think your condition is getting worse, or if they are worried about changes in your behaviour.
Use in Children and Adolescents
Edronax should not normally be used for the treatment of children and adolescents under 18 years of age. The risk of side effects such as suicidal thoughts, suicide attempts, and hostility (predominantly aggression, oppositional behaviour, and anger) is greater in patients under 18 years when they take antidepressants. Despite this, a doctor may prescribe Edronax to patients under 18 years if they decide it is in the patient's best interest. The long-term effects on growth, maturation, and cognitive and behavioural development have not yet been established in this age group.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.
Pregnancy: There is limited data on the use of Edronax during pregnancy. Do not take Edronax if you are pregnant unless your doctor has carefully assessed the benefit-risk ratio and determined it is absolutely necessary. Tell your doctor immediately if you are or plan to become pregnant while taking Edronax.
Breastfeeding: Small amounts of reboxetine are excreted into breast milk, and there is a risk of a potential effect on the infant. You should discuss this with your doctor, who will decide whether you should stop breastfeeding or stop treatment with Edronax, taking into account the benefit of breastfeeding for the child and the benefit of therapy for you.
Driving and Operating Machinery
Exercise caution when driving or operating machinery while taking Edronax. You should not drive or use machinery until you know how Edronax affects you, as it may cause drowsiness, dizziness, or impaired concentration, particularly at the start of treatment or after dose changes. You are personally responsible for assessing whether you are fit to drive or perform tasks requiring alertness.
How Does Edronax Interact with Other Drugs?
Edronax can interact with several medications, including MAO inhibitors, other antidepressants, antifungals, antibiotics, epilepsy drugs, and herbal supplements such as St. John's Wort. Always inform your doctor about all medications you are taking, including over-the-counter products and herbal remedies.
Reboxetine is primarily metabolised by the liver enzyme CYP3A4. Drugs that inhibit this enzyme can increase reboxetine blood levels, while drugs that induce CYP3A4 can decrease its effectiveness. Additionally, combining Edronax with other medications that affect norepinephrine or serotonin pathways can increase the risk of serious adverse effects, including serotonin syndrome.
Major Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| MAO Inhibitors (e.g. phenelzine, tranylcypromine, moclobemide) | Antidepressant | Risk of serotonin syndrome and hypertensive crisis due to combined noradrenergic and serotonergic potentiation | Do not combine. Wait at least 2 weeks after stopping an MAO inhibitor before starting Edronax |
| Linezolid | Antibiotic (MAO inhibitor) | Linezolid has MAO-inhibiting properties; risk of serotonin syndrome | Avoid combination unless no alternative; close monitoring required |
| Methylene blue | Diagnostic/therapeutic agent (MAO inhibitor) | Methylene blue inhibits MAO; risk of serotonin syndrome | Avoid combination; use alternative agents when possible |
| SSRIs (e.g. fluvoxamine, fluoxetine, sertraline) | Antidepressant | Increased risk of serotonin syndrome; fluvoxamine also inhibits CYP3A4, raising reboxetine levels | Avoid combination or use with extreme caution under specialist supervision |
| SNRIs (e.g. venlafaxine, duloxetine) | Antidepressant | Additive noradrenergic and serotonergic effects; risk of serotonin syndrome | Avoid combination |
| Tricyclic antidepressants (e.g. amitriptyline, nortriptyline) | Antidepressant | Overlapping noradrenergic effects and risk of serotonin syndrome | Avoid combination; allow adequate washout period when switching |
Moderate Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Ketoconazole | Antifungal | Strong CYP3A4 inhibitor that significantly increases reboxetine blood levels | Dose reduction of Edronax may be necessary; monitor for increased side effects |
| Erythromycin | Macrolide antibiotic | CYP3A4 inhibitor that increases reboxetine levels | Monitor for increased side effects; consider dose adjustment |
| Rifampicin | Antibiotic (TB treatment) | Strong CYP3A4 inducer that decreases reboxetine effectiveness | Monitor for reduced antidepressant effect; dose increase may be needed |
| Carbamazepine / Phenytoin / Phenobarbital | Antiepileptics | CYP3A4 inducers that reduce reboxetine blood levels | Monitor antidepressant effect; dose adjustment may be required |
| St. John's Wort (Hypericum perforatum) | Herbal supplement | CYP3A4 inducer that may reduce reboxetine levels; also risk of serotonin syndrome | Avoid concurrent use |
| Ergotamine derivatives | Migraine / Parkinson's treatment | Potential pharmacodynamic interaction affecting cardiovascular system | Use with caution; monitor blood pressure and cardiovascular status |
| Triptans (e.g. sumatriptan) | Migraine treatment | Risk of serotonin syndrome when combined with noradrenergic antidepressants | Use with caution; monitor for symptoms of serotonin syndrome |
| Opioids (e.g. tramadol, buprenorphine) | Pain management | Increased risk of serotonin syndrome, especially with tramadol | Use with caution; monitor for signs of serotonin syndrome |
| Thiazide diuretics (non-potassium-sparing) | Diuretic | May increase the risk of hyponatraemia (low sodium levels) when combined with reboxetine | Monitor serum sodium levels, particularly in elderly patients |
Always tell your doctor or pharmacist about all medications you are taking, including prescription drugs, over-the-counter medicines, herbal remedies, and vitamin or mineral supplements. Your doctor will determine whether it is safe for you to take Edronax alongside other medications.
Edronax can be taken with or without food. There are no specific food interactions that require dietary restrictions. However, alcohol should be used with caution as it may enhance the sedative effects of the medication and can worsen depressive symptoms.
What Is the Correct Dosage of Edronax?
The recommended starting dose for adults is 8 mg per day, taken as 4 mg twice daily (morning and evening). Your doctor may increase the dose to 10 mg per day after 3–4 weeks if needed. The maximum daily dose is 12 mg.
Always take Edronax exactly as your doctor or pharmacist has told you. Do not change your dose without consulting your doctor first. Swallow the tablets with a glass of water. The tablet can be split into two equal halves along the score line if needed. Do not chew the tablets.
Adults
Major Depressive Disorder
Starting dose: 8 mg per day (one 4 mg tablet twice daily)
Dose adjustment: After 3–4 weeks, your doctor may increase the dose to 10 mg per day if you have not responded adequately
Maximum dose: 12 mg per day
Take one dose in the morning and one dose in the evening, ideally at the same times each day to maintain consistent blood levels. Like other antidepressants, Edronax will not relieve your symptoms immediately. You should start to feel better within a couple of weeks, but it may take longer for the full effect to develop.
It is important to continue taking your tablets even if you feel better, until your doctor advises you to stop. Stopping treatment too early increases the risk of your symptoms returning. Most international guidelines recommend continuing antidepressant treatment for at least 6 to 12 months after achieving remission from a first depressive episode, and longer in patients with recurrent depression.
Patients with Kidney or Liver Impairment
Reduced Starting Dose
Starting dose: 4 mg per day (one 4 mg tablet once daily)
This dose may be increased depending on individual response and tolerability. Reboxetine is extensively metabolised by the liver and excreted via the kidneys, so impaired function of either organ can lead to higher drug levels in the blood. Your doctor will monitor you more closely and adjust the dose carefully.
Elderly Patients
The use of Edronax is not recommended in elderly patients. Clinical experience in this population is limited, and elderly patients may be more susceptible to side effects such as orthostatic hypotension (drop in blood pressure upon standing), urinary retention, and dizziness. If your doctor decides that Edronax is appropriate for you, they will start with a lower dose and monitor you carefully.
Children and Adolescents
Edronax should not be used by children and adolescents under 18 years of age due to an increased risk of suicidal behaviour and lack of established efficacy and safety data in this age group.
Missed Dose
If you forget to take a dose of Edronax, simply take your next dose at the usual time. Do not take a double dose to make up for the missed one. If you frequently forget doses, consider setting a daily alarm or keeping your medication alongside items you use every morning and evening.
Overdose
If you take more Edronax than prescribed, or if a child accidentally ingests the medication, contact your doctor, hospital, or poison control centre immediately for risk assessment and advice. Never take more tablets than your doctor recommends. Overdose symptoms may include low blood pressure (hypotension), anxiety, and elevated blood pressure (hypertension). Seek emergency medical attention without delay.
Stopping Edronax
You should not stop taking Edronax without first talking to your doctor, as your depressive symptoms may return. There have been reports of withdrawal symptoms when patients have abruptly discontinued Edronax, including headache, dizziness, nervousness, and nausea. Your doctor will typically recommend a gradual dose reduction over several weeks to minimise the risk of withdrawal effects.
What Are the Side Effects of Edronax?
The most common side effects of Edronax include insomnia, dizziness, dry mouth, constipation, nausea, and excessive sweating. These affect more than 1 in 10 people but are usually mild and tend to improve after the first few weeks of treatment.
Like all medicines, Edronax can cause side effects, although not everyone experiences them. Most side effects are mild and tend to diminish after the first few weeks of continued treatment. If any side effects become severe or troublesome, or if you notice effects not listed here, contact your doctor or pharmacist.
- Signs of serotonin syndrome: confusion, agitation, rapid heartbeat, fever, sweating, muscle twitching, tremor, diarrhoea
- Suicidal thoughts or thoughts of self-harm
- Severe allergic reactions: skin rash, swelling of the face or throat, difficulty breathing
- Inability to urinate (urinary retention)
- Signs of glaucoma: severe eye pain, blurred vision, seeing halos around lights
Very Common
May affect more than 1 in 10 people
- Insomnia (difficulty sleeping)
- Dizziness
- Dry mouth
- Constipation
- Nausea
- Excessive sweating (hyperhidrosis)
Common
May affect up to 1 in 10 people
- Headache
- Loss of appetite (anorexia)
- Agitation, anxiety, restlessness
- Paraesthesia (tingling or numbness), akathisia (inability to sit still), altered taste
- Blurred vision (difficulty focusing)
- Increased heart rate (tachycardia), palpitations
- Vasodilation, orthostatic hypotension (drop in blood pressure when standing), elevated blood pressure
- Vomiting
- Skin rash
- Urinary hesitancy, feeling of incomplete bladder emptying, urinary tract infection, painful urination, urinary retention
- Erectile dysfunction (impotence), painful ejaculation, delayed ejaculation
- Chills
Uncommon
May affect up to 1 in 100 people
- Dilated pupils (mydriasis)
- Vertigo (sensation of spinning)
Rare and Very Rare
May affect up to 1 in 1,000 people or fewer
- Glaucoma (increased pressure in the eye)
Frequency Not Known
Reported from post-marketing surveillance
- Serotonin syndrome (see Warnings section)
- Hyponatraemia (very low sodium levels in the blood)
- Aggression, hallucinations
- Suicidal thoughts and suicidal behaviour
- Cold hands and feet, Raynaud's phenomenon (poor blood circulation in extremities, causing pale, cold, and numb skin)
- Allergic skin inflammation (dermatitis)
- Testicular pain
- Irritability
- Increased intraocular pressure
If you experience any side effects not listed here, or if any side effect becomes severe, contact your doctor or pharmacist. Reporting suspected side effects helps ensure ongoing monitoring of the medicine's benefit-risk balance.
How Should You Store Edronax?
Store Edronax tablets below 25°C, out of the reach and sight of children. If supplied in a bottle, keep it tightly closed as the tablets are moisture-sensitive. Do not use after the expiry date.
Keep Edronax out of the sight and reach of children at all times. Do not use this medicine after the expiry date stated on the carton or packaging. The expiry date refers to the last day of the stated month.
Store at or below 25°C (77°F). If your tablets come in a high-density polyethylene (HDPE) bottle, keep the bottle tightly closed as the tablets are moisture-sensitive. The bottle contains a desiccant cylinder (silica gel) that must remain in the bottle to protect your tablets. Do not swallow the desiccant.
Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer need. These measures help protect the environment.
What Does Edronax Contain?
Each Edronax tablet contains 4 mg of reboxetine as the active ingredient. The tablets are white, round, convex, and scored for easy splitting.
The active substance is reboxetine. Each tablet contains 4 mg of reboxetine (as reboxetine mesilate).
The other ingredients (excipients) are:
- Microcrystalline cellulose
- Dibasic calcium phosphate dihydrate
- Crospovidone
- Colloidal anhydrous silica (silicon dioxide)
- Magnesium stearate
Appearance: Edronax 4 mg tablets are white, round, convex tablets with a score line on one side. The tablet is marked "P" on the left and "U" on the right side of the score line. On the other side, the tablet is marked "7671". The tablet can be divided into two equal halves.
Available pack sizes: 10, 20, 50, 60, 100, 120, or 180 tablets in blister packs, and multipacks of 3×60, 5×60, and 10×60 tablets. Bottles of 20 or 60 tablets in HDPE bottles with child-resistant caps are also available. Not all pack sizes may be marketed in every country.
Frequently Asked Questions About Edronax
Edronax (reboxetine) is used to treat major depressive disorder (clinical depression) in adults. It is prescribed for both the acute treatment of depressive episodes and for maintenance therapy to prevent relapse. It works by selectively increasing norepinephrine levels in the brain, helping to improve mood, energy, motivation, and concentration. Unlike SSRIs, Edronax primarily targets the noradrenergic system, which may make it particularly effective for symptoms such as fatigue, psychomotor slowing, and social withdrawal.
Edronax works by a fundamentally different mechanism than SSRIs. While SSRIs (such as sertraline or fluoxetine) selectively block serotonin reuptake, Edronax selectively blocks norepinephrine reuptake. This means it targets a different neurotransmitter system in the brain. Clinically, this may translate to different side-effect profiles – for example, Edronax is less likely to cause sexual dysfunction of the type commonly associated with SSRIs, but is more likely to cause urinary difficulties and insomnia. The choice between an SSRI and Edronax depends on individual patient factors and symptom profile.
Like most antidepressants, Edronax typically takes approximately 2 to 4 weeks to produce noticeable improvement in depressive symptoms. Some patients may notice early improvements in energy levels and motivation within the first week, but the full antidepressant effect usually develops gradually over several weeks. It is crucial to continue taking Edronax as prescribed even if you do not feel immediate improvement, and to discuss your progress with your doctor at regular follow-up appointments.
While there is no absolute contraindication to alcohol consumption while taking Edronax, it is generally advisable to limit or avoid alcohol. Alcohol is a central nervous system depressant that can worsen the symptoms of depression. Additionally, combining alcohol with Edronax may increase the risk of side effects such as dizziness, drowsiness, and impaired judgement. Discuss alcohol use with your doctor, especially if you have concerns about interactions with your medication.
Edronax (reboxetine) is generally considered weight-neutral and may even cause a slight reduction in appetite and body weight in some patients. Loss of appetite is listed as a common side effect. This differentiates Edronax from some other antidepressants, particularly mirtazapine, paroxetine, and tricyclic antidepressants, which are more commonly associated with weight gain. If weight management is a concern, discuss this with your doctor when choosing an antidepressant.
There is limited safety data on the use of reboxetine during pregnancy. Do not take Edronax if you are pregnant unless your doctor has carefully evaluated the risks and benefits and concluded it is absolutely necessary. If you become pregnant while taking Edronax, inform your doctor immediately. Your doctor may recommend an alternative antidepressant with a more established safety profile during pregnancy, or may determine that continuing Edronax is the best option given your clinical circumstances.
References
- European Medicines Agency (EMA). Edronax – Summary of Product Characteristics (SmPC). Available at: www.ema.europa.eu. Accessed January 2026.
- National Institute for Health and Care Excellence (NICE). Depression in adults: treatment and management. NICE guideline [NG222]. Updated 2022. Available at: www.nice.org.uk.
- American Psychiatric Association (APA). Practice Guideline for the Treatment of Patients with Major Depressive Disorder, Third Edition. 2010. Available at: psychiatryonline.org.
- World Health Organization (WHO). Depression: Key Facts. 2023. Available at: www.who.int.
- Cipriani A, et al. Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. The Lancet. 2018;391(10128):1357-1366. doi:10.1016/S0140-6736(17)32802-7.
- Eyding D, et al. Reboxetine for acute treatment of major depression: systematic review and meta-analysis of published and unpublished placebo and selective serotonin reuptake inhibitor controlled trials. BMJ. 2010;341:c4737. doi:10.1136/bmj.c4737.
- British National Formulary (BNF). Reboxetine. Available at: bnf.nice.org.uk. Accessed January 2026.
- Hajak G, et al. Reboxetine in the treatment of major depressive disorder: pooled analysis of efficacy and tolerability. International Clinical Psychopharmacology. 2004;19(3):115-124.
Editorial Team
Written by
iMedic Medical Editorial Team
Specialists in Psychiatry and Clinical Pharmacology
Reviewed by
iMedic Medical Review Board
Independent panel following WHO, NICE and APA guidelines