Selegiline - MAO-B Inhibitor for Parkinson's Disease

Selegiline (Eldepryl, Zelapar)

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">Selegiline - MAO-B Inhibitor for Parkinson's Disease</th>
</tr>
<tr>
<td class="label">Drug Class</td>
<td>MAO-B Inhibitor</td>
</tr>
<tr>
<td class="label">Approval Status</td>
<td>FDA Approved (1989)</td>
</tr>
<tr>
<td class="label">Brand Names</td>
<td>Eldepryl, Zelapar, Emsam (transdermal)</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Irreversible MAO-B inhibition</td>
</tr>
<tr>
<td class="label">Route of Administration</td>
<td>Oral, Transdermal</td>
</tr>
<tr>
<td class="label">Half-life</td>
<td>1-2 hours (oral), 18-25 hours (transdermal)</td>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Value</td>
</tr>
<tr>
<td class="label">Bioavailability</td>
<td>~25% (oral)</td>
</tr>
<tr>
<td class="label">Protein Binding</td>
<td>~90%</td>
</tr>
<tr>
<td class="label">Metabolism</td>
<td>Hepatic (CYP450 enzymes)</td>
</tr>
<tr>
<td class="label">Elimination</td>
<td>Renal (~80%)</td>
</tr>
<tr>
<td class="label">Duration of MAO-B Inhibition</td>
<td>Irreversible (requires new enzyme synthesis, ~2 weeks)</td>
</tr>
<tr>
<td class="label">Interacting Drug</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">SSRIs (fluoxetine, sertraline)</td>
<td>Serotonin syndrome risk</td>
</tr>
<tr>
<td class="label">*Tyramine-rich foods

...

Selegiline (Eldepryl, Zelapar)

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">Selegiline - MAO-B Inhibitor for Parkinson's Disease</th>
</tr>
<tr>
<td class="label">Drug Class</td>
<td>MAO-B Inhibitor</td>
</tr>
<tr>
<td class="label">Approval Status</td>
<td>FDA Approved (1989)</td>
</tr>
<tr>
<td class="label">Brand Names</td>
<td>Eldepryl, Zelapar, Emsam (transdermal)</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Irreversible MAO-B inhibition</td>
</tr>
<tr>
<td class="label">Route of Administration</td>
<td>Oral, Transdermal</td>
</tr>
<tr>
<td class="label">Half-life</td>
<td>1-2 hours (oral), 18-25 hours (transdermal)</td>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Value</td>
</tr>
<tr>
<td class="label">Bioavailability</td>
<td>~25% (oral)</td>
</tr>
<tr>
<td class="label">Protein Binding</td>
<td>~90%</td>
</tr>
<tr>
<td class="label">Metabolism</td>
<td>Hepatic (CYP450 enzymes)</td>
</tr>
<tr>
<td class="label">Elimination</td>
<td>Renal (~80%)</td>
</tr>
<tr>
<td class="label">Duration of MAO-B Inhibition</td>
<td>Irreversible (requires new enzyme synthesis, ~2 weeks)</td>
</tr>
<tr>
<td class="label">Interacting Drug</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">SSRIs (fluoxetine, sertraline)</td>
<td>Serotonin syndrome risk</td>
</tr>
<tr>
<td class="label">Tyramine-rich foods</td>
<td>Hypertensive crisis (high doses)</td>
</tr>
<tr>
<td class="label">Meperidine</td>
<td>Potentially fatal interaction</td>
</tr>
<tr>
<td class="label">TCAs</td>
<td>Serotonin syndrome risk</td>
</tr>
</table>

Introduction

Overview

Selegiline is a monoamine oxidase-B (MAO-B) inhibitor used in the treatment of Parkinson's disease and major depressive disorder. It acts by irreversibly inhibiting the enzyme MAO-B, which metabolizes dopamine in the brain, thereby increasing dopamine availability and extending the duration of levodopa's effect. [@parkinson1989]

Mechanism of Action

Selegiline selectively and irreversibly inhibits monoamine oxidase type B (MAO-B) in the brain:

Dopamine Protection: MAO-B normally degrades dopamine; inhibition preserves endogenous dopamine

Levodopa Enhancement: When combined with levodopa/carbidopa, selegiline allows for lower levodopa doses

Neuroprotective Effects: May provide independent neuroprotective activity through antioxidant effects

Metabolite Effects: Produces amphetamine metabolites (l-methamphetamine, l-amphetamine) at low doses

Clinical Applications

Parkinson's Disease

• Early Monotherapy: Used as initial treatment for mild PD symptoms
• Adjunct to Levodopa: Reduces "off" time and extends "on" time
• Motor Fluctuation Management: Helps manage wearing-off phenomenon

Major Depressive Disorder

• Transdermal Form (Emsam): FDA-approved for treatment-resistant depression
• Low Risk of Tyramine Interaction: At low doses, does not require dietary restrictions

Off-Label Uses

• Cognitive enhancement in Alzheimer's disease
• Narcolepsy management
• Binge eating disorder

Pharmacokinetics

Side Effects

Common Side Effects

• Nausea, dry mouth
• Insomnia or sleep disturbances
• Headache
• Orthostatic hypotension
• Dyskinesia (especially with levodopa)

Serious Side Effects

• Hypertensive crisis (with high-dose oral or tyramine-rich foods)
• Serotonin syndrome (when combined with SSRIs)
• Hallucinations or psychosis

Drug Interactions

Therapeutic Considerations

Advantages

• Long-term efficacy established in PD
• Once-daily oral dosing
• May slow disease progression (controversial)
• Transdermal option avoids first-pass metabolism

Limitations

• Must be discontinued 2 weeks before SSRIs
• Dietary restrictions at higher doses
• Dyskinesia emergence with long-term use
• Limited efficacy as monotherapy in advanced PD

Clinical Trials

KEY TRIALS

DATATOP Study (1989): Selegiline delayed need for levodopa in early PD

Pinkelman et al. (1995): Reduced off-time in levodopa-treated patients

The Selegiline Research Group: Confirmed motor symptom improvement

Research Directions

• Neuroprotection: Investigating disease-modifying potential
• Combination Therapies: Studies with dopamine agonists
• Transdermal Delivery: Expanding use in depression
• Biomarker Studies: Identifying responders

See Also

• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Levodopa](/therapeutics/levodopa)
• [Rasagiline](/therapeutics/rasagiline)
• [MAO-B Inhibitors](/therapeutics/mao-b-inhibitors)
• [Dopamine Agonists](/therapeutics/dopamine-agonists)
• [COMT Inhibitors](/therapeutics/entacapone)

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/)
• [ClinicalTrials.gov](https://clinicaltrials.gov/)

Background

The study of Selegiline Mao B Inhibitor For Parkinson'S Disease has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Allen Brain Atlas Resources

• [Allen Brain Atlas - Gene Expression](https://human.brain-map.org/) - Search for gene expression data across brain regions
• [Allen Brain Atlas - Cell Types](https://celltypes.brain-map.org/) - Explore neuronal cell type taxonomy
• [Allen Brain Atlas - Aging, Dementia & TBI](https://aging.brain-map.org/) - Data on aging and traumatic brain injury

Mechanism of Action

References

[Unknown, Parkinson Study Group. "Effect of selegiline on the progression of Parkinson's disease." JAMA. 1989;261(19):2883-2898 (1989)](https://pubmed.ncbi.nlm.nih.gov/2523976/)

[Unknown, The Selegiline Research Group. "A controlled trial of selegiline in Parkinson disease." Arch Neurol. 1993;50(10):1023-1029 (1993)](https://pubmed.ncbi.nlm.nih.gov/8215957/)

[Youdim MB, Bakhle YS, "Monoamine oxidase: isoforms and inhibitors in Parkinson's disease and depressive illness." Br J Pharmacol (2006)](https://pubmed.ncbi.nlm.nih.gov/16402108/)

[Riederer P, Laux G, "MAO-inhibitors in Parkinson's disease." Exp Neurobiol (2011)](https://pubmed.ncbi.nlm.nih.gov/21472060/)

[Factor SA, Weiner WJ, "Selegiline in the treatment of Parkinson's disease." Expert Opin Pharmacother (2002)](https://pubmed.ncbi.nlm.nih.gov/12150685/)

[Birkmayer W, Riederer P, Youdim MB, "Selegiline (Eldepryl): from tissue culture to neuronal rescue." J Neural Transm Suppl (1996)](https://pubmed.ncbi.nlm.nih.gov/8988462/)

[Knoll J, "The pharmacology of selegiline ((-)-deprenyl)." J Neural Transm Suppl (1994)](https://pubmed.ncbi.nlm.nih.gov/7953065/)

[Amiri S, et al, "Selegiline in the treatment of major depressive disorder." Neuropsychiatr Dis Treat (2014)](https://pubmed.ncbi.nlm.nih.gov/25082973/)

Related Hypotheses

From the [SciDEX Exchange](/exchange) — scored by multi-agent debate

• [Microbial Metabolite-Mediated α-Synuclein Disaggregation](/hypothesis/h-74777459) — <span style="color:#ffd54f;font-weight:600">0.57</span> · Target: SNCA, HSPA1A, DNMT1