What do you know about Selegiline?

Selegiline 5mg is a medication primarily used to treat Parkinson’s disease and major depressive disorder (MDD). It works by inhibiting the enzyme monoamine oxidase B (MAO-B) in the brain, which plays a role in breaking down certain neurotransmitters like dopamine, serotonin, and norepinephrine. By inhibiting MAO-B, selegiline helps increase the levels of dopamine in the brain, which is beneficial for individuals with Parkinson’s disease, who suffer from dopamine deficiency.

Here are the key details about selegiline:

1. Parkinson’s Disease Treatment:

• Selegiline 5mg  is often used as an adjunct treatment to levodopa (a common Parkinson’s drug), especially in the early stages. It can help enhance the effects of levodopa and reduce motor fluctuations.
• The MAO-B inhibition slows the breakdown of dopamine, which helps improve movement control.

2. Depression:

• Selegiline 5mg  is also prescribed for major depressive disorder (MDD), especially in cases where other antidepressants haven’t been effective. The transdermal form (patch) is frequently used for depression.
• It acts as a monoamine oxidase inhibitor (MAOI) but specifically targets MAO-B at lower doses. At higher doses, it can also inhibit MAO-A, which is involved in breaking down serotonin and norepinephrine.

3. Mechanism of Action:

• Selegiline 5mg  is a selective, irreversible MAO-B inhibitor at lower doses. This is important because MAO-B is responsible for breaking down dopamine, and its inhibition results in more available dopamine in the brain.
• At higher doses, selegiline can inhibit MAO-A, leading to increased levels of serotonin and norepinephrine. This effect is typically seen when used for depression.

4. Forms and Dosage:

• Oral tablets are commonly used for Parkinson’s, taken once or twice a day.
• Transdermal patch (for depression) is applied to the skin and provides a more consistent dose.
• Oral disintegrating tablets (ODTs) are another form that can be used for depression.

5. Side Effects:

• Common side effects include nausea, dizziness, headache, insomnia, and dry mouth.
• At higher doses (especially when it acts as a MAOI), there may be a risk of hypertensive crisis (high blood pressure) if combined with foods containing tyramine (like aged cheeses, cured meats, and certain alcoholic beverages). This is due to the MAO-A inhibition at higher doses.
• Serotonin syndrome is also a risk when selegiline is taken with other drugs that increase serotonin levels (e.g., selective serotonin reuptake inhibitors, or SSRIs).

6. Drug Interactions:

• Care must be taken when combining selegiline with antidepressants (especially other MAOIs, SSRIs, or SNRIs) due to the potential for serotonin syndrome.
• It can also interact with sympathomimetic drugs (e.g., certain cold medications, stimulants) and cause dangerous blood pressure increases.

7. Precautions:

• Patients with liver or kidney problems may need to have their dosage adjusted.
• It should be used cautiously in patients with a history of hypertension, heart disease, or glaucoma.

Selegiline has been a cornerstone in the treatment of Parkinson’s disease, and its role in managing depression, particularly with its transdermal formulation, continues to be explored.