Eldepryl (Selegiline)
MAO-B inhibitor for the treatment of Parkinson's disease
Eldepryl contains the active ingredient selegiline, a selective and irreversible inhibitor of monoamine oxidase type B (MAO-B). It is used to treat Parkinson's disease, either as monotherapy in early-stage disease to delay the need for levodopa, or as adjunctive therapy with levodopa to enhance its effect and reduce motor fluctuations. This comprehensive guide covers uses, dosage, side effects, drug interactions, and important safety information based on international clinical guidelines.
Quick Facts
Key Takeaways
- Eldepryl (selegiline) is a selective MAO-B inhibitor used to treat Parkinson's disease by increasing dopamine levels in the brain.
- It can be used as monotherapy in early Parkinson's disease to delay the need for levodopa by approximately 9 months.
- When combined with levodopa, Eldepryl extends the duration of levodopa's effect and may allow dose reduction.
- Eldepryl must never be combined with SSRIs, SNRIs, tricyclic antidepressants, pethidine, tramadol, or other MAO inhibitors due to the risk of serotonin syndrome.
- Common side effects include dizziness, dry mouth, nausea, and involuntary movements, which are usually mild and manageable.
What Is Eldepryl and What Is It Used For?
Eldepryl belongs to a class of medications known as monoamine oxidase type B (MAO-B) inhibitors. The active substance, selegiline, works by selectively and irreversibly inhibiting the MAO-B enzyme in the brain. This enzyme is responsible for the metabolic breakdown of dopamine, the neurotransmitter that is progressively lost in Parkinson's disease. By inhibiting MAO-B, selegiline increases the availability of dopamine in the striatum, thereby helping to improve motor function and reduce the symptoms of Parkinson's disease.
Parkinson's disease is a chronic, progressive neurodegenerative disorder characterised by the loss of dopamine-producing neurons in the substantia nigra region of the brain. The resulting dopamine deficiency leads to the cardinal motor symptoms: resting tremor, rigidity (muscle stiffness), bradykinesia (slowness of movement), and postural instability. These symptoms typically develop gradually and worsen over time, significantly impacting quality of life and functional independence.
Eldepryl may be used in two distinct clinical scenarios. In early-stage Parkinson's disease, it can be prescribed as monotherapy to provide symptomatic relief and delay the point at which levodopa therapy becomes necessary. The landmark DATATOP (Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism) trial demonstrated that selegiline can postpone the need for levodopa by approximately 9 months in newly diagnosed patients. This delay is clinically meaningful because it allows patients to avoid the long-term complications of levodopa therapy, such as motor fluctuations and dyskinesias, for a longer period.
In later-stage disease, Eldepryl is used as an adjunct to levodopa-containing medications. When added to levodopa therapy, selegiline extends the duration of each levodopa dose by slowing the breakdown of the dopamine produced from levodopa. This is particularly beneficial for patients experiencing "wearing-off" phenomena — the recurrence of parkinsonian symptoms before the next scheduled levodopa dose. By enhancing the effect of levodopa, selegiline often allows a reduction in the total daily levodopa dose, which may in turn reduce levodopa-related side effects.
It is important to understand that selegiline does not cure Parkinson's disease or halt the underlying neurodegenerative process. However, by optimising dopaminergic transmission, it provides meaningful symptom control and can improve the patient's ability to perform daily activities. Whether selegiline has true neuroprotective properties — that is, whether it slows the progression of neuronal loss independently of its symptomatic effects — remains a topic of ongoing research and scientific debate.
What Should You Know Before Taking Eldepryl?
Contraindications
There are several important situations in which Eldepryl must not be used. Your doctor will assess whether this medication is appropriate for you, but it is essential that you are aware of the following absolute contraindications:
- Allergy to selegiline — Do not take Eldepryl if you have a known hypersensitivity to selegiline hydrochloride or any of the excipients (mannitol, magnesium stearate, povidone, microcrystalline cellulose, maize starch).
- Active peptic ulcer disease — Eldepryl is contraindicated in patients with active duodenal or gastric ulcers.
- Concurrent use of SSRIs — Selective serotonin reuptake inhibitors such as fluoxetine, sertraline, paroxetine, citalopram, and escitalopram must not be combined with Eldepryl.
- Concurrent use of SNRIs — Serotonin-norepinephrine reuptake inhibitors such as venlafaxine and duloxetine are contraindicated.
- Concurrent use of tricyclic antidepressants — Medications such as amitriptyline, nortriptyline, and imipramine must not be used with Eldepryl.
- Concurrent use of sympathomimetics — Drugs that stimulate the sympathetic nervous system are contraindicated.
- Concurrent use of other MAO inhibitors — Including linezolid (an antibiotic with MAO-inhibiting properties).
- Concurrent use of opioids containing pethidine (meperidine) — This combination can cause a potentially fatal reaction characterised by hyperthermia, rigidity, myoclonus, and altered consciousness.
Combining Eldepryl with serotonergic medications (SSRIs, SNRIs, tricyclic antidepressants, pethidine, tramadol) can trigger serotonin syndrome — a potentially life-threatening condition characterised by agitation, hyperthermia, rigidity, tremor, tachycardia, and altered mental status. Seek emergency medical attention immediately if you experience these symptoms.
Warnings and Precautions
Your doctor should be informed if you have any of the following conditions, as special monitoring or dose adjustments may be required:
- History of peptic ulcer disease — Even if the ulcer has healed, the risk of recurrence should be considered.
- Unstable hypertension — Selegiline may affect blood pressure regulation in some patients.
- Cardiac arrhythmias — Particularly relevant in patients with pre-existing rhythm disturbances.
- Severe angina pectoris — Careful cardiac monitoring is advisable.
- Severe hepatic impairment — Selegiline is extensively metabolised by the liver, and impaired hepatic function may alter drug metabolism and increase the risk of adverse effects.
- Severe renal impairment — Dose adjustments may be necessary.
- Psychosis — Selegiline may exacerbate psychotic symptoms, including hallucinations and confusion.
Patients with Parkinson's disease treated with dopaminergic medications, including selegiline, may develop impulse control disorders. These include pathological gambling, increased libido, hypersexuality, compulsive eating, compulsive shopping, and repetitive purposeless behaviours (punding). If you or your carers notice any of these behaviours, inform your doctor promptly, as dose adjustment or discontinuation of the medication may be necessary.
Pregnancy and Breastfeeding
There is limited clinical experience with the use of selegiline during pregnancy. Animal studies have not been conducted with adequate assessment of reproductive toxicity. As a precautionary measure, Eldepryl should not be used during pregnancy unless the potential benefit clearly outweighs the potential risk to the foetus. Women of childbearing potential should discuss contraceptive options with their doctor.
It is not known whether selegiline or its metabolites pass into breast milk. Given the pharmacological profile of the drug and its metabolites (which include L-methamphetamine and L-amphetamine), Eldepryl should not be used during breastfeeding. If treatment with selegiline is deemed essential, breastfeeding should be discontinued.
Driving and Operating Machinery
Eldepryl may cause dizziness, which can impair your ability to drive or operate machinery safely. If you experience dizziness while taking Eldepryl, you should refrain from driving or operating dangerous machinery until the symptoms resolve. This is particularly important during the initial period of treatment or after dose adjustments. Parkinson's disease itself may also affect driving ability, and this should be assessed individually.
How Does Eldepryl Interact with Other Drugs?
Drug interactions are a major safety concern with Eldepryl. Because selegiline inhibits monoamine oxidase, it can interact with a wide range of medications that affect monoamine neurotransmitters (serotonin, norepinephrine, dopamine). Understanding these interactions is critical to safe prescribing and patient safety. Always inform your doctor and pharmacist about all medications you are currently taking, including over-the-counter drugs and herbal supplements.
Major Interactions (Contraindicated)
The following medications must never be used together with Eldepryl due to the risk of serious or life-threatening adverse reactions:
| Drug / Drug Class | Risk | Clinical Significance |
|---|---|---|
| SSRIs (fluoxetine, sertraline, paroxetine, citalopram) | Serotonin syndrome | Potentially fatal; allow 2-5 weeks washout after SSRI discontinuation |
| SNRIs (venlafaxine, duloxetine) | Serotonin syndrome | Potentially fatal; absolute contraindication |
| Tricyclic antidepressants (amitriptyline, nortriptyline) | Enhanced serotonergic and noradrenergic effects | Risk of hypertensive crisis and serotonin syndrome |
| Pethidine (meperidine) | Hyperthermia, rigidity, death | Potentially fatal; inform surgeon/anaesthetist before any procedure |
| Tramadol | Serotonin syndrome, seizures | Must not be combined; use alternative analgesics |
| Buprenorphine | Enhanced opioid effects | Must not be combined with Eldepryl |
| Sympathomimetics (ephedrine, pseudoephedrine) | Hypertensive crisis | Includes many cold/flu remedies; check all OTC medications |
| Other MAO inhibitors (linezolid, moclobemide) | Hypertensive crisis, serotonin syndrome | Absolute contraindication; allow adequate washout period |
Interactions Requiring Caution or Dose Adjustment
The following medications may be used with Eldepryl but require careful medical supervision, monitoring, or dose adjustments:
| Drug | Interaction | Action Required |
|---|---|---|
| Levodopa | Selegiline enhances levodopa effect; may increase dyskinesias and other dopaminergic side effects | Levodopa dose reduction (typically 10-30%) may be needed |
| Dopamine (intravenous) | Enhanced pressor response | Use with caution in shock or cardiac emergencies |
| Oral contraceptives | May enhance the effect of selegiline through enzyme inhibition | Monitor for increased side effects; inform your doctor |
| Digitalis glycosides | Possible altered drug levels | Careful monitoring required |
| Anticoagulants (warfarin) | Possible altered anticoagulant effect | More frequent INR monitoring |
Food and Alcohol Interactions
At the standard therapeutic dose of 10 mg daily, selegiline is selective for MAO-B and does not significantly inhibit MAO-A in the gut. This means that the strict tyramine-free diet required with non-selective MAO inhibitors is generally not necessary with Eldepryl at recommended doses. However, if selegiline is used concurrently with moclobemide (an MAO-A inhibitor), tyramine-rich foods — such as aged cheeses, fermented meats, sauerkraut, soy sauce, and yeast extracts — should be avoided to prevent hypertensive reactions.
Alcohol should be avoided while taking Eldepryl. Alcohol can potentiate the sedative effects of selegiline and may worsen dizziness, a common side effect. Additionally, some alcoholic beverages (particularly red wine and unpasteurised beers) contain tyramine.
What Is the Correct Dosage of Eldepryl?
Eldepryl should always be taken exactly as prescribed by your doctor. The tablets should be swallowed whole with water. Timing of administration is important — selegiline should be taken in the morning to minimise the risk of sleep disturbances, as its metabolites include amphetamine-like compounds that can cause insomnia if taken later in the day.
Adults
Monotherapy (Early Parkinson's Disease)
The usual dose is 10 mg daily, taken as a single dose in the morning. This may be administered as one 10 mg tablet or two 5 mg tablets.
Combination Therapy (With Levodopa or Other Parkinson's Medications)
The dose is 5–10 mg daily. This may be taken as a single morning dose or divided between morning and lunchtime (e.g., 5 mg in the morning and 5 mg at lunch). When selegiline is added to levodopa therapy, the levodopa dose may need to be reduced by 10–30% to avoid excessive dopaminergic stimulation.
Elderly Patients
No specific dose adjustment is generally required for elderly patients. However, given that Parkinson's disease predominantly affects older adults, and that hepatic and renal function may decline with age, careful dose titration and monitoring are recommended. Elderly patients may be more susceptible to orthostatic hypotension and psychiatric side effects such as hallucinations and confusion.
Children
Eldepryl is not recommended for use in children and adolescents. Parkinson's disease is exceedingly rare in the paediatric population, and the safety and efficacy of selegiline have not been established in patients under 18 years of age.
Missed Dose
If you forget to take a dose of Eldepryl, take it as soon as you remember, provided it is still morning or early afternoon. If more than 12 hours have elapsed since the scheduled dose, skip the missed dose and take the next dose at the usual time the following morning. Do not take a double dose to make up for a forgotten dose. Taking selegiline late in the day may cause difficulty sleeping.
Overdose
There is limited clinical experience with selegiline overdose. However, at supratherapeutic doses, selegiline loses its selectivity for MAO-B and begins to inhibit MAO-A as well, which significantly increases the risk of hypertensive crisis and serotonin syndrome. Symptoms of overdose may include agitation, irritability, severe headache, hallucinations, rapid heartbeat, increased blood pressure, hyperthermia, and in severe cases, seizures and cardiovascular collapse.
If you suspect an overdose, seek emergency medical attention immediately. Contact your local poison control centre or go to the nearest emergency department. There is no specific antidote for selegiline overdose; treatment is supportive and symptomatic.
What Are the Side Effects of Eldepryl?
Like all medicines, Eldepryl can cause side effects, although not everyone experiences them. The nature and frequency of side effects may differ depending on whether selegiline is used as monotherapy or in combination with levodopa. When used with levodopa, selegiline enhances levodopa's effects, which means that levodopa-related side effects may become more prominent. In many cases, these can be managed by reducing the levodopa dose.
Common
May affect up to 1 in 10 people
- Dizziness
- Involuntary movements (dyskinesia)
- Dry mouth
- Nausea
- Transient and/or mildly elevated liver enzymes
- Confusion
- Anxiety
- Hallucinations
- Psychiatric reactions
- Headache
- Slow heart rate (bradycardia)
Uncommon
May affect up to 1 in 100 people
- Mood swings
- Rapid heart rate (tachycardia)
- Dry mouth
- Mild transient sleep disturbances
Rare
May affect up to 1 in 1,000 people
- Skin rash
- Restlessness (akathisia)
- Difficulty urinating
- Orthostatic hypotension (drop in blood pressure upon standing)
Frequency Not Known
Cannot be estimated from available data
- Impulse control disorders: pathological gambling, increased libido, hypersexuality, compulsive eating, compulsive shopping
- Repetitive purposeless behaviours (punding)
- Urinary retention
Side Effects When Used With Levodopa
When Eldepryl is used in combination with levodopa, it enhances the effect of levodopa and may amplify levodopa-related side effects. The most commonly reported combination-related side effects include:
- Restlessness and agitation — Often manageable by reducing the levodopa dose.
- Abnormal involuntary movements (dyskinesia) — May indicate that the levodopa dose is too high.
- Confusion and hallucinations — More common in elderly patients or those with cognitive impairment.
- Orthostatic hypotension — Dizziness or lightheadedness when standing up quickly, caused by a drop in blood pressure.
- Cardiac arrhythmias — Irregular heartbeat, particularly in patients with pre-existing cardiac conditions.
These side effects typically resolve or improve when the levodopa dose is reduced. Your doctor will monitor you closely and adjust your medication regimen as needed. Do not alter your medication doses without consulting your doctor.
Contact your doctor promptly if you experience severe or persistent side effects, signs of serotonin syndrome (agitation, fever, rapid heartbeat, muscle rigidity), new or worsening psychiatric symptoms (hallucinations, paranoia, unusual behaviour), unexplained skin rash, or any allergic reaction. Seek emergency medical attention if you experience difficulty breathing, severe chest pain, or loss of consciousness.
How Should You Store Eldepryl?
Proper storage of Eldepryl is essential to maintain the stability and effectiveness of the medication. Selegiline is sensitive to light, which can cause chemical degradation of the active ingredient over time. Follow these storage guidelines:
- Temperature: Store at or below 25°C (77°F). Do not freeze.
- Light protection: Keep the tablets in the original packaging to protect from light.
- Moisture: Store in a dry place. Avoid storing in bathrooms or near sinks.
- Child safety: Keep out of sight and reach of children.
- Expiry date: Do not use Eldepryl after the expiry date stated on the packaging. The expiry date refers to the last day of that month.
Do not dispose of medications via the toilet or household waste. Ask your pharmacist how to dispose of medicines that are no longer needed. These measures help to protect the environment and prevent accidental exposure.
What Does Eldepryl Contain?
Understanding the full composition of your medication is important, particularly if you have known allergies or intolerances to specific pharmaceutical excipients. Below is the complete list of ingredients in Eldepryl tablets:
Active Ingredient
Selegiline hydrochloride — Each tablet contains 5 mg of selegiline hydrochloride. Selegiline is the (R)-enantiomer of deprenyl and is also known as L-deprenyl. It is a propargylamine derivative that acts as an irreversible, selective inhibitor of monoamine oxidase type B (MAO-B).
Inactive Ingredients (Excipients)
- Mannitol — A sugar alcohol used as a tablet filler and sweetening agent.
- Magnesium stearate — A lubricant that prevents the tablet from sticking to manufacturing equipment during compression.
- Povidone (polyvinylpyrrolidone) — A binding agent that helps hold the tablet together.
- Microcrystalline cellulose — A plant-derived filler and binder that provides structural integrity to the tablet.
- Maize starch — A disintegrant that helps the tablet break down in the gastrointestinal tract for absorption.
Tablet Appearance
Eldepryl 5 mg tablets are white, round, and convex, with a diameter of 6 mm. They are supplied in plastic containers of 100 tablets.
Eldepryl is manufactured by Orion Corporation Orion Pharma (Salo, Finland) and marketed by Orion Pharma. The marketing authorisation is held by Orion Corporation (Espoo, Finland).
Frequently Asked Questions About Eldepryl
Eldepryl (selegiline) is a selective MAO-B inhibitor, meaning it primarily blocks the MAO-B enzyme at therapeutic doses. This is distinct from non-selective MAO inhibitors (such as phenelzine and tranylcypromine), which inhibit both MAO-A and MAO-B. The selectivity of selegiline for MAO-B at standard doses means that the strict tyramine-free diet required with non-selective MAO inhibitors is generally not necessary. Additionally, selegiline is used specifically for Parkinson's disease, whereas non-selective MAO inhibitors are primarily used for depression. Another MAO-B inhibitor, rasagiline (Azilect), is also used for Parkinson's disease and has a similar mechanism but different pharmacokinetic properties.
If you are scheduled for surgery, it is essential to inform your surgeon, anaesthetist, and all healthcare providers involved that you are taking Eldepryl. This is critically important because pethidine (meperidine), a pain medication commonly used during and after surgical procedures, must never be combined with selegiline due to the risk of a potentially fatal reaction. Your anaesthetist will choose alternative analgesics that are safe to use with MAO-B inhibitors. Your doctor may advise discontinuing Eldepryl before elective surgery, but this decision should be made on a case-by-case basis.
This is one of the most debated questions in Parkinson's disease research. The DATATOP trial initially suggested that selegiline might have neuroprotective properties, as it delayed the need for levodopa therapy. However, subsequent analyses suggested that much of this benefit could be attributed to selegiline's symptomatic (dopamine-sparing) effect rather than true neuroprotection. Laboratory studies have shown that selegiline has antioxidant and anti-apoptotic properties that could theoretically protect neurons, but this has not been conclusively demonstrated in clinical trials. At present, selegiline is classified as a symptomatic treatment for Parkinson's disease.
Selegiline begins inhibiting MAO-B within hours of the first dose, but the full clinical benefit may take several weeks to develop. This is because the therapeutic effect depends on the gradual accumulation of dopamine in the brain as more and more MAO-B enzyme molecules are irreversibly inhibited. When used as monotherapy, improvement in motor symptoms such as tremor, rigidity, and bradykinesia typically becomes noticeable within 2 to 6 weeks. When added to levodopa therapy, the benefit — such as reduced "wearing-off" effects — may be apparent sooner, sometimes within days.
While selegiline does not typically cause physical dependence or a withdrawal syndrome, abruptly stopping the medication is not recommended. Because MAO-B inhibition by selegiline is irreversible, the enzyme activity takes approximately 2–3 weeks to fully recover after discontinuation (as new enzyme must be synthesised). However, if you are also taking levodopa, stopping selegiline may lead to a noticeable worsening of Parkinson's symptoms because the dopamine-sparing effect of selegiline is lost. Your doctor should manage any changes to your medication regimen, including gradual adjustments to levodopa dosing if selegiline is discontinued.
Both Eldepryl (selegiline) and Azilect (rasagiline) are selective, irreversible MAO-B inhibitors used to treat Parkinson's disease. However, they differ in important ways. Selegiline is metabolised to L-methamphetamine and L-amphetamine, which may contribute to some side effects (such as insomnia). Rasagiline is metabolised to 1(R)-aminoindan, which does not have amphetamine-like properties. Clinically, both medications are effective at reducing motor symptoms and extending levodopa's effect. Your doctor will choose the most appropriate MAO-B inhibitor based on your individual clinical profile, tolerability, and other medications you are taking.
References
This article is based on the following peer-reviewed sources and international clinical guidelines:
- Parkinson Study Group. (1993). Effects of tocopherol and deprenyl on the progression of disability in early Parkinson's disease (DATATOP). New England Journal of Medicine, 328(3), 176–183. DOI: 10.1056/NEJM199301213280305
- European Medicines Agency (EMA). Selegiline — Summary of Product Characteristics. Available at: www.ema.europa.eu
- National Institute for Health and Care Excellence (NICE). (2017, updated 2024). Parkinson's disease in adults: diagnosis and management. NICE Guideline NG71. Available at: www.nice.org.uk/guidance/ng71
- Fox, S.H., et al. (2018). International Parkinson and Movement Disorder Society Evidence-Based Medicine Review: Update on Treatments for the Motor Symptoms of Parkinson's Disease. Movement Disorders, 33(8), 1248–1266.
- Riederer, P., & Laux, G. (2011). MAO-inhibitors in Parkinson's Disease. Experimental Neurobiology, 20(1), 1–17. DOI: 10.5607/en.2011.20.1.1
- World Health Organization (WHO). Model List of Essential Medicines, 23rd List (2023). Geneva: WHO.
- British National Formulary (BNF). Selegiline hydrochloride. Available at: bnf.nice.org.uk
- Olanow, C.W., et al. (2009). A double-blind, delayed-start trial of rasagiline in Parkinson's disease (ADAGIO study). New England Journal of Medicine, 361(13), 1268–1278.
- Ives, N.J., et al. (2004). Monoamine oxidase type B inhibitors in early Parkinson's disease: meta-analysis of 17 randomised trials involving 3525 patients. BMJ, 329(7466), 593.
Editorial Team
This article was written and reviewed by the iMedic Medical Editorial Team, comprising licensed specialist physicians in neurology, clinical pharmacology, and movement disorders.
iMedic Medical Editorial Team — specialists in neurology and clinical pharmacology with expertise in Parkinson's disease and neurodegenerative disorders.
iMedic Medical Review Board — independent panel of medical experts who review all content according to WHO, EMA, AAN, and NICE guidelines using the GRADE evidence framework.
Published: | Last reviewed: | Evidence level: 1A (systematic reviews and meta-analyses of RCTs)