Selegiline

Introduction: What is Selegiline?

Selegiline is primarily used in the treatment of Parkinson's disease. The transdermal form (Emsam) is approved for major depressive disorders. It belongs to a class of drugs known as monoamine oxidase inhibitors (MAOIs). By inhibiting the enzyme monoamine oxidase, Selegiline helps increase the levels of certain neurotransmitters in the brain, which can improve mood and motor function.

Uses of Selegiline

Selegiline is approved for several medical uses, including:

• Parkinson's Disease: It is often prescribed to help manage symptoms of Parkinson's disease, particularly in the early stages or as an adjunct to other medications.
• Major Depressive Disorder: The transdermal form (Emsam) is FDA approved for treatment-resistant depression.

How Does It Work?

Selegiline works by blocking the action of monoamine oxidase, an enzyme that breaks down neurotransmitters like dopamine, serotonin, and norepinephrine. By inhibiting this enzyme, Selegiline increases the availability of these neurotransmitters in the brain, which can enhance mood and improve motor control in patients with Parkinson's disease. Selegiline selectively inhibits monoamine oxidase type B (MAO-B) at low doses used in Parkinson's disease, primarily increasing dopamine levels. At higher doses or transdermally, it also inhibits MAO-A.

Dosage and Administration

The dosage of Selegiline can vary based on the condition being treated:

• For Parkinson's Disease: The typical starting dose for the oral selective MAO-B inhibitor is 5 mg taken once daily (often increased to 10 mg/day), based on the patient's response and tolerance.
• For Major Depressive Disorder: The usual dose for transdermal Emsam is 6 mg to 12 mg/24h.

Administration: Selegiline is available in various forms, including oral tablets and transdermal patches. The patch is applied to the skin and provides a continuous release of the medication.

Side Effects of Selegiline

Common side effects of Selegiline may include:

• Nausea
• Dizziness
• Insomnia
• Dry mouth
• Headache

Serious side effects can include:

• Hypertensive crisis: severe increase in blood pressure (due to tyramine or sympathomimetics)
• Serotonin syndrome: a potentially life-threatening condition caused by excessive serotonin (especially with serotonergic agents)
• Allergic reactions

Drug Interactions

Selegiline can interact with several medications and substances, including:

• Other Antidepressants: Combining Selegiline with SSRIs, SNRIs, or other MAOIs can increase the risk of serotonin syndrome.
• Certain Foods: Foods high in tyramine (like aged cheeses and cured meats) can cause hypertensive crises when taken with Selegiline.
• Stimulants: Medications like amphetamines can also interact negatively with Selegiline.

Benefits of Selegiline

The clinical advantages of using Selegiline include:

• Improved Motor Function: In Parkinson's patients, Selegiline can enhance motor control and reduce symptoms.
• Mood Enhancement: It can help alleviate symptoms of depression, particularly in patients who have not responded to other treatments.
• Neuroprotective Effects: Some early studies suggested neuroprotective properties, but larger trials (e.g., DATATOP) showed no disease-modifying effect; benefits are symptomatic.

Contraindications of Selegiline

Certain individuals should avoid using Selegiline, including:

• Pregnant or Nursing Women: Pregnancy (Category C; avoid unless benefits outweigh risks). The effects on fetal development are not well-studied.
• Patients with Liver Disease: Selegiline is metabolized in the liver, and impaired liver function can increase the risk of side effects.
• Individuals with a History of Hypertension: Due to the risk of hypertensive crises.
• Uncontrolled hypertension.

Precautions and Warnings

Before starting Selegiline, patients should discuss their medical history with their healthcare provider. Important precautions include:

• Regular Monitoring: Blood pressure should be monitored regularly, especially when starting treatment.
• Avoiding Certain Foods: Patients should be educated about dietary restrictions related to tyramine.
• Lab Tests: Routine lab tests may be necessary to monitor liver function and overall health.

FAQs

• What is Selegiline used for? Selegiline is primarily used to treat Parkinson's disease. The transdermal form (Emsam) is approved for major depressive disorders.
• How does Selegiline work? It inhibits enzyme monoamine oxidase, increasing levels of neurotransmitters like dopamine and serotonin in the brain.
• What are the common side effects? Common side effects include nausea, dizziness, and dry mouth.
• Can I take Selegiline with other medications? You should consult your doctor, as Selegiline can interact with many medications.
• Is Selegiline safe during pregnancy? It is generally not recommended for pregnant women due to potential risks.
• How is Selegiline administered? It can be taken as an oral tablet or applied as a transdermal patch.
• What should I avoid while taking Selegiline? Avoid foods high in tyramine and certain medications that can cause interactions.
• Can Selegiline cause serotonin syndrome? Yes, especially if taken with other antidepressants.
• How long does it take for Selegiline to work? Patients may start to notice improvements within a few weeks, but it can vary.
• What should I do if I miss a dose? Take it as soon as you remember but skip it if it's almost time for your next dose.

Brand Names

Selegiline is marketed under several brand names, including:

• Eldepryl
• Zelapar
• EMSAM (transdermal patch)

Conclusion

Selegiline is a valuable medication in the management of Parkinson's disease and depression. Its ability to enhance neurotransmitter levels can lead to significant improvements in mood and motor function. However, it is essential to use this medication under the guidance of a healthcare provider due to potential side effects and interactions. Always consult your doctor before starting or stopping any medication.