Comprehensive Guide to Selegiline: Uses, Dosage, Side Effects, and More

1. What is Selegiline?

2. Overview of Selegiline

Generic Name

Selegiline

Brand Name

Eldepryl, Zelapar, generics

Drug Group

Monoamine oxidase inhibitor (MAOI, antiparkinsonian/antidepressant)

Commonly Used For

This medication is used to:

• Treat Parkinson’s disease.
• Manage depressive disorders.
• Alleviate motor symptoms as an adjunct.

Key Characteristics

• Form: Oral tablets (5 mg, 10 mg), orally disintegrating tablets (1.25 mg), transdermal patch (6 mg/24h, 9 mg/24h, 12 mg/24h) (detailed in Dosage section).
• Mechanism: Selectively inhibits MAO-B, boosting dopamine availability.
• Approval: FDA-approved (1989 for Eldepryl) and EMA-approved for Parkinson’s disease.

3. Indications and Uses of Selegiline

Selegiline is indicated for neurological and psychiatric conditions, leveraging its dopaminergic and monoaminergic effects:

• Parkinson’s Disease: Treats early and advanced Parkinson’s disease, improving motor symptoms (e.g., tremor, rigidity) as monotherapy or with levodopa, per neurological guidelines, with long-term efficacy data.
• Depressive Disorders: Manages major depressive disorder (MDD) as a transdermal patch, especially in treatment-resistant cases, enhancing mood stability, supported by psychiatry trials.
• Early-Stage Parkinson’s: Used as initial therapy in early Parkinson’s to delay levodopa use, preserving motor function, with evidence from movement disorder studies.
• Alzheimer’s Disease with Depression: Investigated off-label to address depression and cognitive decline in Alzheimer’s patients, improving quality of life, supported by geriatric psychiatry research.
• Restless Legs Syndrome (RLS): Employed off-label to reduce RLS symptoms in refractory cases, enhancing sleep quality, with data from sleep medicine studies.
• Attention Deficit Hyperactivity Disorder (ADHD): Explored off-label as an adjunct in adult ADHD, improving focus, with emerging pediatric and adult psychiatry evidence.
• Chronic Fatigue Syndrome (CFS): Used off-label to alleviate fatigue and cognitive symptoms in CFS, with preliminary data from chronic illness research.
• Huntington’s Disease: Investigated off-label to manage chorea and mood symptoms in Huntington’s, with cautious use under neurology supervision.
• Post-Stroke Depression: Applied off-label to treat depression post-stroke, improving recovery, supported by stroke rehabilitation studies.

Note: This drug requires dietary restrictions and monitoring; consult a healthcare provider for individualized management.

4. Dosage of Selegiline

Important Note: The dosage of this MAOI must be prescribed by a healthcare provider. Dosing varies by formulation, indication, and patient response, with adjustments based on clinical evaluation.

Dosage for Adults

• Parkinson’s Disease (Oral Tablets):
  • Initial: 5 mg twice daily with breakfast and lunch, maximum 10 mg/day.
  • Adjunct with Levodopa: 5 mg with breakfast, titrated to 10 mg/day.
• Parkinson’s Disease (Orally Disintegrating Tablets):
  • Initial: 1.25 mg daily, increased to 2.5 mg after 6 weeks if needed, maximum 2.5 mg/day.
• Major Depressive Disorder (Transdermal Patch):
  • Initial: 6 mg/24h applied daily, titrated to 9 mg/24h or 12 mg/24h after 4 weeks, maximum 12 mg/24h.

Dosage for Children

• Parkinson’s Disease or ADHD (off-label):
  • 1.25–2.5 mg orally disintegrating tablets daily, under pediatric neurologist or psychiatrist supervision.
  • Not recommended under 12 years unless critical.

Dosage for Pregnant Women

• Pregnancy Category C: Limited data; use only if benefits outweigh risks. Consult an obstetrician, with fetal monitoring.

Dosage Adjustments

• Renal Impairment: No adjustment needed; monitor in severe cases (CrCl <30 mL/min).
• Hepatic Impairment:
  • Mild (Child-Pugh A): No adjustment; moderate (Child-Pugh B): Reduce dose by 50%; severe (Child-Pugh C): Avoid.
• Elderly: Start with 5 mg or 6 mg/24h patch; increase cautiously.
• Concomitant Medications: Adjust if combined with SSRIs, SNRIs, or sympathomimetics, increasing serotonin syndrome risk.

Additional Considerations

• Take this active ingredient with food (tablets) or apply patch to dry, hairless skin (e.g., upper torso, thigh), avoiding irritation.
• Follow a low-tyramine diet to prevent hypertensive crisis.

5. How to Use Selegiline

• Administration:
  • Swallow tablets with food and water; place orally disintegrating tablets on tongue to dissolve; apply transdermal patch to clean, dry skin, rotating sites.
  • Take or apply at consistent times daily (e.g., morning for tablets, evening for patch if tolerated).
• Timing: Use once or twice daily (tablets) or once daily (patch), as directed.
• Monitoring: Watch for headache, neck stiffness, or signs of serotonin syndrome (e.g., agitation).
• Additional Tips:
  • Store at 20–25°C (68–77°F), protecting tablets from moisture and patches from heat.
  • Keep out of reach of children due to overdose risk.
  • Report severe chest pain, confusion, or signs of allergic reaction immediately.

6. Contraindications for Selegiline

This drug is contraindicated in:

• Hypersensitivity: Patients with a known allergy to Selegiline or MAOIs.
• Pheochromocytoma: Contraindicated due to hypertensive risk.
• Concurrent Use with Certain Drugs: Avoid with SSRIs, SNRIs, tricyclic antidepressants, or sympathomimetics (e.g., pseudoephedrine) due to serotonin syndrome or hypertension.
• Severe Hepatic Impairment: Contraindicated in Child-Pugh Class C.

7. Warnings & Precautions for Selegiline

General Warnings

• Hypertensive Crisis: Risk with tyramine-rich foods (e.g., aged cheese, cured meats); educate patients on diet.
• Serotonin Syndrome: Risk with serotonergic drugs; monitor for agitation, hyperthermia, or tremors.
• Orthostatic Hypotension: Risk of dizziness; advise slow position changes.
• Sleep Disturbances: Insomnia or vivid dreams; adjust timing if needed.
• Psychiatric Effects: Rare mania or hallucinations; assess mental health.

Additional Warnings

• Cardiovascular Events: Rare myocardial infarction; monitor in at-risk patients.
• Hepatotoxicity: Elevated liver enzymes; check regularly.
• Neurological Effects: Rare dyskinesia with levodopa; reduce dose if present.
• Skin Reactions: Patch site irritation; rotate application sites.
• Hypersensitivity Reactions: Rare anaphylaxis; discontinue if swelling occurs.

Use in Specific Populations

• Pregnancy: Category C; use only if essential with fetal monitoring.
• Breastfeeding: Excreted in breast milk; monitor infant for effects.
• Elderly: Higher risk of hypotension; start with lower doses.
• Children: Limited to 12+ years off-label; supervise closely.
• Renal/Hepatic Impairment: Adjust dose; avoid in severe cases.

Additional Precautions

• Inform your doctor about hypertension, psychiatric history, or medication use before starting this medication.
• Avoid abrupt cessation; taper if discontinuing long-term use.

8. Overdose and Management of Selegiline

Overdose Symptoms

Overdose may cause:

• Headache, hypertension, or tachycardia.
• Severe cases: Serotonin syndrome, seizures, or coma.
• Agitation, sweating, or confusion as early signs.
• Respiratory depression with extremely high doses.

Immediate Actions

• Contact the Medical Team: Seek immediate medical help.
• Supportive Care: Administer IV fluids, monitor vital signs, and control blood pressure with phentolamine if hypertensive.
• Specific Treatment: Manage serotonin syndrome with cyproheptadine or cooling if hyperthermic; no specific antidote.
• Monitor: Check heart rate, mental status, and temperature for 24–48 hours.

Additional Notes

• Overdose risk is moderate; store securely.
• Report persistent symptoms (e.g., severe headache, rigidity) promptly.

9. Side Effects of Selegiline

Common Side Effects

• Insomnia (10–20%, adjust timing)
• Nausea (5–15%, manageable with food)
• Dizziness (4–12%, reduced with hydration)
• Dry Mouth (3–10%, relieved with water)
• Headache (2–8%, decreases with tolerance)
  These effects may subside with dose adjustment.

Serious Side Effects

Seek immediate medical attention for:

• Cardiovascular: Hypertensive crisis or myocardial infarction.
• Neurological: Serotonin syndrome, dyskinesia, or seizures.
• Hepatic: Jaundice or liver failure.
• Psychiatric: Mania, hallucinations, or confusion.
• Allergic: Rash, angioedema, or anaphylaxis.

Additional Notes

• Regular monitoring for blood pressure, liver function, and mental status is advised.
• Report any unusual symptoms (e.g., chest pain, severe agitation) immediately to a healthcare provider.

10. Drug Interactions with Selegiline

This active ingredient may interact with:

• SSRIs/SNRIs: Increases serotonin syndrome risk (e.g., fluoxetine); avoid.
• Sympathomimetics: Enhances hypertension (e.g., pseudoephedrine); avoid.
• Opioids: Potentiates respiratory depression (e.g., meperidine); avoid.
• Antidepressants: Alters effects (e.g., tricyclics); monitor closely.
• Tyramine-Rich Foods: Triggers hypertensive crisis; restrict intake.

Action: Provide your healthcare provider with a complete list of medications and dietary habits.

11. Patient Education or Lifestyle

• Medication Adherence: Take this MAOI as prescribed to manage Parkinson’s or depression, following the exact schedule.
• Monitoring: Report headache, neck stiffness, or mood changes immediately.
• Lifestyle: Avoid tyramine-rich foods (e.g., aged cheese, soy sauce); limit alcohol.
• Diet: Take with food (tablets) or apply patch with meal planning; maintain hydration.
• Emergency Awareness: Know signs of hypertensive crisis or serotonin syndrome; seek care if present.
• Follow-Up: Schedule regular check-ups every 3–6 months to monitor blood pressure, liver function, and symptom control.

12. Pharmacokinetics of Selegiline

• Absorption: Well-absorbed orally (peak at 0.5–2 hours); enhanced with food; transdermal avoids first-pass metabolism.
• Distribution: Volume of distribution ~1,850 L; 90% protein-bound.
• Metabolism: Hepatic via CYP2B6, CYP2C9 to methamphetamine and amphetamine metabolites.
• Excretion: Primarily renal (60–70%) as metabolites; half-life 1–3 hours (active metabolites 10 hours).
• Half-Life: 1–3 hours (parent drug), with prolonged effects from metabolites.

13. Pharmacodynamics of Selegiline

This drug exerts its effects by:

• Selectively inhibiting MAO-B at low doses, increasing dopamine in the brain.
• At higher doses, non-selectively inhibits MAO-A, affecting serotonin and norepinephrine.
• Enhancing motor function in Parkinson’s and mood in depression.
• Exhibiting dose-dependent risks of hypertension and serotonin toxicity.

14. Storage of Selegiline

• Temperature: Store at 20–25°C (68–77°F); protect tablets from moisture and patches from heat.
• Protection: Keep in original container, away from light.
• Safety: Store in a locked container out of reach of children due to toxicity risk.
• Disposal: Dispose of unused tablets or patches per local regulations or consult a pharmacist.

15. Frequently Asked Questions (FAQs) About Selegiline

Q: What does Selegiline treat?
A: This medication treats Parkinson’s disease and depression.

Q: Can this active ingredient cause insomnia?
A: Yes, insomnia may occur; take earlier if needed.

Q: Is Selegiline safe for children?
A: Yes, for 12+ years off-label with a doctor’s guidance.

Q: How is this drug taken?
A: Orally as tablets or patch, as directed.

Q: How long is Selegiline treatment?
A: Long-term for Parkinson’s or depression with monitoring.

Q: Can I use Selegiline if pregnant?
A: Yes, with caution; consult a doctor.

16. Regulatory Information for Selegiline

This medication is approved by:

• U.S. Food and Drug Administration (FDA): Approved in 1989 (Eldepryl) for Parkinson’s, later expanded for depression.
• European Medicines Agency (EMA): Approved for Parkinson’s disease.
• Other Agencies: Approved globally for Parkinson’s and depression; consult local guidelines.

17. References

1. U.S. Food and Drug Administration (FDA). (2023). Eldepryl (Selegiline) Prescribing Information.
   • Official FDA documentation detailing the drug’s approved uses, dosage, and safety.
2. European Medicines Agency (EMA). (2023). Selegiline Summary of Product Characteristics.
   • EMA’s comprehensive information on the medication’s indications and precautions in Europe.
3. National Institutes of Health (NIH). (2023). Selegiline: MedlinePlus Drug Information.
   • NIH resource providing detailed information on the drug’s uses, side effects, and precautions.
4. World Health Organization (WHO). (2023). WHO Model List of Essential Medicines: Selegiline.
   • WHO’s consideration of Selegiline for neurological disorders.
5. Movement Disorders. (2022). Selegiline in Parkinson’s Disease Management.
   • Peer-reviewed article on Selegiline efficacy (note: access may require a subscription).