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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Zelapar
Generic Name
Selegiline Hydrochloride
Active Ingredient
SelegilineCategory
Monoamine Oxidase Inhibitor [EPC]
Salt Form
Hydrochloride
Variants
1
Different strengths and dosage forms
| Strength | Form | Route | NDC |
|---|---|---|---|
| 1.25 mg/1 | TABLET, ORALLY DISINTEGRATING | ORAL | 0187-0453 |
Detailed information about Zelapar
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Zelapar, you must consult a qualified healthcare professional.
Selegiline is a selective monoamine oxidase type B (MAO-B) inhibitor used primarily as an adjunct treatment for Parkinson's disease and, in transdermal form, for major depressive disorder. It works by increasing dopamine levels in the brain to improve motor control and mood.
Dosage of Selegiline varies significantly based on the formulation and the condition being treated.
Selegiline is generally not approved for use in pediatric patients. For Major Depressive Disorder, the Emsam patch carries a specific warning regarding the increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Safety and effectiveness in patients under the age of 18 have not been established for any indication.
For patients with mild to moderate kidney disease, dosage adjustments are typically not required for the oral forms. However, there is limited data on the use of Selegiline in patients with severe renal impairment or end-stage renal disease (ESRD). Healthcare providers will monitor these patients closely for signs of toxicity.
The liver is the primary site of Selegiline metabolism. In patients with hepatic (liver) impairment, the concentration of the drug in the blood can increase significantly. For the Emsam patch, no adjustment is usually needed for mild impairment, but caution is advised in moderate to severe cases. For oral forms, a lower dose or less frequent administration may be considered by the physician.
In clinical trials, elderly patients (over 65) did not show significant differences in safety compared to younger adults. However, because older adults are more prone to orthostatic hypotension (a drop in blood pressure when standing up) and may have age-related declines in kidney or liver function, healthcare providers often start at the lower end of the dosing range.
If you miss a dose of Selegiline, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and return to your regular schedule. Do not double the dose to catch up. For the patch, if you forget to change it, apply a new one as soon as possible and resume your normal 24-hour cycle.
An overdose of Selegiline can be life-threatening and may mimic the symptoms of other MAO inhibitor toxicities. Signs of overdose may not appear immediately and can be delayed by 12 to 24 hours. Symptoms include:
If an overdose is suspected, contact your local poison control center or seek emergency medical attention immediately.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking Selegiline without medical guidance, as sudden discontinuation can lead to a worsening of symptoms.
Side effects of Selegiline can vary depending on whether it is taken orally for Parkinson's or via a patch for depression. Common experiences include:
> Warning: Stop taking Selegiline and call your doctor immediately if you experience any of these symptoms. These may indicate a life-threatening reaction.
With prolonged use, some patients may develop a tolerance to the drug's effects, requiring dosage adjustments. Long-term use in Parkinson's disease is generally well-tolerated, but the risk of levodopa-induced dyskinesia may increase over years of combined therapy. There is also a theoretical risk of 'impulse control disorders,' where patients develop intense urges to gamble, spend money, or engage in other repetitive behaviors, though this is more common with dopamine agonists than with Selegiline.
Suicidality in Children and Young Adults (Emsam Patch only):
The FDA has issued a black box warning for the Selegiline transdermal patch (Emsam). Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies. Anyone considering the use of Emsam in a child or young adult must balance this risk with the clinical need. Families and caregivers should be advised of the need for close observation and communication with the prescriber. It is important to note that Emsam is not approved for use in pediatric patients.
Report any unusual symptoms or changes in mood to your healthcare provider promptly. Monitoring by a physician is essential for the safe long-term use of this medication.
Selegiline is a powerful medication that requires careful monitoring. Patients must be aware of the 'tyramine trap.' At standard doses for Parkinson's (10 mg/day or less), Selegiline is selective for MAO-B and usually does not require a special diet. However, at higher doses (such as the 9 mg or 12 mg Emsam patch), Selegiline loses its selectivity and inhibits MAO-A in the gut. This prevents the breakdown of tyramine, an amino acid found in aged and fermented foods. High levels of tyramine can cause a sudden, massive release of norepinephrine, leading to a hypertensive crisis.
Suicidality Warning (Transdermal Patch):
According to the FDA, Emsam (Selegiline transdermal) is associated with an increased risk of suicidal thinking and behavior in children, adolescents, and young adults (ages 18-24) during initial treatment. Healthcare providers must monitor all patients starting antidepressants for clinical worsening and emergence of suicidal thoughts, especially during the first few months of drug therapy or at times of dose changes.
Your healthcare provider may require the following during Selegiline therapy:
Selegiline may cause dizziness, hallucinations, or sudden 'sleep attacks' (somnolence). Do not drive, operate heavy machinery, or engage in dangerous activities until you know how this medication affects you. If you experience increased sleepiness during the day, consult your doctor immediately.
Alcohol should be avoided while taking Selegiline. Alcohol can increase the sedative effects of the medication and may also contain tyramine (especially tap beers and certain wines), which increases the risk of a hypertensive crisis.
Do not stop taking Selegiline abruptly. Sudden discontinuation can lead to a 'withdrawal' effect or a rapid worsening of Parkinson's symptoms (Neuroleptic Malignant-like Syndrome). If the drug must be stopped, your doctor will provide a tapering schedule to slowly reduce the dose.
> Important: Discuss all your medical conditions, including any history of high blood pressure, heart disease, or mental health issues, with your healthcare provider before starting Selegiline.
Certain drugs should NEVER be used with Selegiline due to the risk of fatal reactions:
Selegiline metabolites (L-methamphetamine) may cause a false positive result on urine drug screens for amphetamines. If you are required to take a drug test for employment or legal reasons, ensure the testing lab is aware you are taking Selegiline so they can perform a confirmatory test (GC/MS) to distinguish between the drug's metabolites and illicit substances.
For each major interaction, the mechanism usually involves either the inhibition of neurotransmitter breakdown (pharmacodynamic) or the competition for liver enzymes (pharmacokinetic). The clinical consequence is often an 'overload' of serotonin or norepinephrine, leading to toxicity. The management strategy is always to maintain a strict 'washout period' when changing medications and to consult a pharmacist before starting any new over-the-counter product.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, including those for cough, cold, or weight loss.
Selegiline must NEVER be used in the following circumstances:
Conditions requiring careful risk-benefit analysis by a physician:
While Selegiline is chemically distinct from other MAOIs, patients who have had severe adverse reactions to other MAO inhibitors (like Rasagiline or Safinamide) should be monitored closely for similar reactions. There is no documented cross-allergy between Selegiline and other classes of antidepressants or Parkinson's medications, but caution is always warranted when introducing a new drug to a sensitive patient.
> Important: Your healthcare provider will evaluate your complete medical history, including any history of heart rhythm problems or mental health disorders, before prescribing Selegiline. Always ensure your medical record is up to date.
Selegiline is classified as FDA Pregnancy Category C. This means that animal reproduction studies have shown an adverse effect on the fetus, but there are no adequate and well-controlled studies in humans. In animal studies, Selegiline was associated with decreased pup survival and body weight. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. If you are planning a pregnancy or become pregnant while taking Selegiline, consult your neurologist or psychiatrist immediately to discuss alternative treatments.
It is not known whether Selegiline or its metabolites are excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants (such as irritability or changes in blood pressure), a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. Most clinicians advise against breastfeeding while taking MAOIs.
Selegiline is not approved for use in children. In the case of the Emsam patch, there is a specific risk of suicidality. Furthermore, the risk of a hypertensive crisis (the 'cheese effect') may be harder to manage in children who may not adhere strictly to dietary restrictions. For Parkinson's disease, the condition is extremely rare in children, and Selegiline's safety in this context has never been studied.
Parkinson's disease primarily affects older adults, so Selegiline has been studied extensively in this population. While generally effective, elderly patients are at a higher risk for:
In patients with mild to moderate renal impairment, the pharmacokinetics of Selegiline are not significantly altered. However, for those with severe impairment or those on dialysis, the metabolites (amphetamine/methamphetamine) may accumulate. While no specific dose adjustment is mandated by the FDA, a 'start low, go slow' approach is recommended.
For patients with liver disease, the oral forms of Selegiline should be used with caution. The transdermal patch (Emsam) has been studied in patients with hepatic impairment; while mild impairment doesn't require a dose change, the 6 mg/24 hour dose is usually the maximum recommended for those with more significant liver dysfunction to prevent toxicity.
> Important: Special populations require individualized medical assessment. Never share your medication with others, especially those in these sensitive categories.
Selegiline is a 'suicide' or 'irreversible' inhibitor of Monoamine Oxidase (MAO). It works by binding to the FAD (flavin adenine dinucleotide) cofactor of the MAO enzyme. At clinical doses of 10 mg/day or less, it is highly selective for the MAO-B isoform. MAO-B is the primary enzyme responsible for the oxidative deamination of dopamine in the human striatum. By blocking this enzyme, Selegiline increases the concentration of synaptic dopamine. Additionally, Selegiline may interfere with the reuptake of dopamine from the synaptic cleft, further enhancing dopaminergic activity. At higher doses (typically >20 mg orally or the higher-strength patches), it loses selectivity and inhibits MAO-A, which is why dietary restrictions become necessary at higher doses.
The onset of MAO-B inhibition is rapid, occurring within hours of the first dose. However, the clinical 'benefit' in Parkinson's symptoms may take several weeks to become apparent. Because the inhibition is irreversible, the effect persists for approximately 10 to 14 days after the last dose is taken—this is the time required for the body to manufacture new MAO enzymes. This 'lag time' is critical when switching to other medications that might interact with Selegiline.
| Parameter | Value |
|---|---|
| Bioavailability | <10% (Oral); ~73% (Transdermal) |
| Protein Binding | 90% - 94% |
| Half-life | 1.5 - 2 hours (Parent drug); 18-25 hours (Metabolites) |
| Tmax | 0.5 - 2 hours (Oral) |
| Metabolism | Hepatic (CYP2B6, CYP3A4, CYP2C19) |
| Excretion | Renal (~73%), Fecal (~15%) |
Selegiline is classified as a Monoamine Oxidase Type B Inhibitor [EPC]. It is part of the broader category of antiparkinsonian agents and antidepressants. Related medications include Rasagiline (Azilect) and Safinamide (Xadago), which are also selective MAO-B inhibitors, and Phenelzine (Nardil), which is a non-selective MAO inhibitor.
Common questions about Zelapar
Selegiline is primarily used as an add-on treatment for Parkinson's disease to help manage 'wearing-off' symptoms associated with levodopa/carbidopa therapy. In its transdermal patch form (Emsam), it is also FDA-approved to treat Major Depressive Disorder in adults. By inhibiting the enzyme that breaks down dopamine, it helps improve motor control in Parkinson's patients. For depression, it works by increasing levels of mood-regulating chemicals like serotonin and norepinephrine in the brain. It is not a cure for either condition but helps manage symptoms effectively.
The most common side effects depend on the form of the medication used. For oral tablets used in Parkinson's, nausea, dizziness, abdominal pain, and insomnia are frequently reported. For the transdermal patch used for depression, skin irritation at the application site is the most common issue. Some patients also experience dry mouth and a drop in blood pressure when standing up. Most mild side effects decrease over time as the body adjusts to the medication, but you should always report persistent symptoms to your doctor.
It is strongly recommended to avoid alcohol while taking Selegiline. Alcohol can worsen the side effects of the drug, such as dizziness and sleepiness, increasing the risk of falls or accidents. Furthermore, certain types of alcohol, particularly tap beers and some red wines, contain tyramine. Combining tyramine with an MAO inhibitor like Selegiline can lead to a dangerous spike in blood pressure known as a hypertensive crisis. To ensure your safety, it is best to abstain from alcohol entirely during treatment.
Selegiline is classified as Pregnancy Category C, meaning its safety in human pregnancy has not been established. Animal studies have suggested potential risks to the fetus, including decreased birth weight and survival rates. Because of the lack of human data, it is only prescribed during pregnancy if the benefits clearly outweigh the potential risks. If you are pregnant or planning to become pregnant, you must discuss your treatment options with your healthcare provider. They will help you weigh the risks of the medication against the risks of untreated Parkinson's or depression.
While Selegiline begins inhibiting enzymes in the brain shortly after the first dose, the clinical benefits are not immediate. For Parkinson's disease, it may take 2 to 4 weeks of consistent use to notice an improvement in 'wearing-off' symptoms or motor control. For the treatment of depression using the transdermal patch, it typically takes 2 to 6 weeks for a significant improvement in mood to occur. It is important to continue taking the medication exactly as prescribed, even if you do not feel better right away.
No, you should never stop taking Selegiline suddenly without consulting your doctor. Abruptly stopping the medication can cause a rapid return of Parkinson's symptoms and, in rare cases, a dangerous condition called Neuroleptic Malignant-like Syndrome, characterized by high fever and muscle rigidity. For those taking it for depression, stopping suddenly can lead to withdrawal symptoms or a relapse of depressive symptoms. Your doctor will provide a gradual tapering schedule to safely reduce the dose over several weeks.
If you miss a dose of Selegiline, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, skip the missed dose and continue with your regular routine. You should never take two doses at once to make up for a missed one, as this increases the risk of side effects and blood pressure spikes. If you are using the patch and forget to change it, apply a new one as soon as possible. Consistency is key to maintaining stable levels of the drug in your system.
Weight gain is not a common side effect of Selegiline; in fact, some patients may experience slight weight loss due to side effects like nausea or a decrease in appetite. This is a notable difference from some other antidepressants or psychiatric medications that are frequently associated with significant weight gain. However, everyone's body reacts differently to medication. If you notice significant or rapid changes in your weight while taking Selegiline, you should discuss this with your healthcare provider to determine the underlying cause.
Selegiline has many serious drug interactions, so it must be used with caution alongside other medications. It should never be taken with meperidine, certain cough medicines containing dextromethorphan, or other MAO inhibitors. Combining Selegiline with SSRIs or SNRIs can lead to a life-threatening condition called Serotonin Syndrome. Always provide your doctor and pharmacist with a complete list of all prescription drugs, over-the-counter medicines, and herbal supplements you are taking to avoid dangerous interactions.
Yes, Selegiline is available as a generic medication in its oral tablet and capsule forms, which can significantly reduce the cost for patients. The orally disintegrating tablet (Zelapar) and the transdermal patch (Emsam) may also have generic versions available, depending on your region and the current patent status. Generic medications are required by the FDA to have the same active ingredient, strength, and effectiveness as the brand-name versions. Check with your pharmacist to see if a generic version is appropriate for your prescription.
Other drugs with the same active ingredient (Selegiline)