Selgin

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Selgin

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Selgin

Quick Facts

Property Description
Active ingredient Selegiline hydrochloride (L-deprenyl)
Form Oral tablets, Buccal tablets, Transdermal patch
Pharmacological class Selective Monoamine Oxidase B (MAO-B) Inhibitor
General purpose Dopamine preservation in the central nervous system
Origin Synthetic compound (Phenethylamine derivative)

Selegiline: Definition and Origin of the Active Ingredient

Selgin is a trade name for a medication containing the active ingredient Selegiline hydrochloride, which is also known chemically as L-deprenyl. This drug is a synthetic compound, developed as a propargylamine derivative from phenethylamine. The medication is designed as a single-ingredient product and is available for different routes of administration, including standard oral tablets and specialized forms like the transdermal patch (Emsam) and buccal tablets (Zelapar). This variety in forms constitutes a differentiating factor, allowing distinct delivery profiles for the same core ingredient.

Pharmacological Classification: What Type of Inhibitor is Selgin?

Selegiline belongs to the pharmacological class of Monoamine oxidase inhibitors (MAOIs), where it functions specifically as a selective, irreversible MAO-B inhibitor. This means the drug targets and permanently neutralizes the Monoamine oxidase type B (MAO-B) enzyme in the central nervous system. This selectivity minimizes potential adverse effects often associated with less selective MAO inhibitors. The drug’s position as a potent and selective MAO-B inhibitor is recognized for its therapeutic applications.

General Purpose: The Role of Dopamine Preservation

The fundamental purpose of Selegiline is to support neurological function by facilitating the preservation of dopamine, a vital chemical messenger, within the brain. By inhibiting the MAO-B enzyme, the medication significantly reduces the rate of natural dopamine breakdown. This mechanism leads to sustained, increased dopamine concentration in the striatum, providing a foundational stabilizing effect for neurological communication.

Regulatory References

  1. MedlinePlus

What side effects are possible with Selgin?

Adverse reaction scope

Component Description
Key adverse reaction categories Gastrointestinal, Neurological/Psychiatric, Cardiovascular/Vascular, Musculoskeletal, and Dermatological effects.
Frequency classification Very Common (ge 10%): Nausea, Fatigue, Anorexia, Application Site Reaction (Transdermal). Common (ge 1% to <10%): Dyskinesia, Dizziness, Insomnia, Dry Mouth, Constipation, Headache, Hypotension, Confusion, and Anxiety.
System-organ classes involved Nervous System Disorders, Psychiatric Disorders, Gastrointestinal Disorders, Vascular Disorders, Cardiac Disorders, and Skin and Subcutaneous Tissue Disorders.
Serious adverse reactions (as documented in regulatory sources) Serotonin Syndrome, Hypertensive Crisis (when MAO-B selectivity is lost or due to specific interactions), Neuroleptic Malignant Syndrome (NMS)-like Symptom Complex (following rapid discontinuation), Impulse Control/Compulsive Behaviors, and Falling Asleep During Activities of Daily Living.
Population-specific safety considerations (if applicable) Older Adults: Increased frequency of hypertension and orthostatic hypotension. Severe Renal/Hepatic Impairment: Not recommended. Pregnancy: FDA Category C.
Dose- or exposure-related patterns (if explicitly stated) Exacerbation of Levodopa Side Effects (e.g., dyskinesia) when used adjunctively. Orthostatic Hypotension risk is increased following dose escalations.
Safety-related restrictions or limitations The selective MAO-B inhibition is gradually lost at increasing daily doses. The orally disintegrating tablet contains phenylalanine (relevant for PKU patients). The transdermal patch site must avoid direct external heat.

Safety classifications (high-level)

  • Regulatory frequency framework used: Standardized frequency categories (e.g., Very Common, Common) based on aggregated data from clinical trials and post-marketing surveillance.
  • Regulatory basis: The safety profile is based on the prescribing information and safety documents issued by major government authorities, including the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA).
  • Context-of-use safety notes: Safety requires careful consideration of concomitant serotonergic drugs (risk of Serotonin Syndrome) and avoiding certain high-tyramine foods and sympathomimetic drugs, especially at higher-than-recommended doses.

Resulting safety structure

  • The official safety profile outlines adverse reactions across multiple System-Organ Classes, ranging from very common gastrointestinal and neurological effects to rare hypertensive reactions.
  • It explicitly documents several Serious Adverse Reactions, including Serotonin Syndrome and NMS-like withdrawal symptoms, which represent critical safety points.
  • Safety constraints are defined for special patient populations, such as those with severe renal or hepatic impairment, and are tied to specific dose- or exposure-related patterns, such as the risk of losing selectivity at increased doses.

Connection to the overall safety profile

The official safety information establishes a risk-based framework by categorizing effects by frequency and system involvement, providing a factual basis for understanding the medicine's documented characteristics. The explicit listing of Serious Adverse Reactions and Population-Specific Constraints defines the critical safety boundaries under which the medication has been evaluated by regulatory authorities. This structure ensures that the officially identified safety characteristics are communicated without interpretation or benefit framing.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory documents define the overdose of selegiline by its potential to cause severe MAOI class toxicity, which is often serious and sometimes fatal.

Overdose manifestations may be delayed up to 12 hours post-ingestion, and the peak syndrome intensity may not be reached for up to 48 hours.

Classification Component Official Regulatory Statement
Documented Overdose Presentations: CNS: Drowsiness, agitation, hyperactivity, severe headache, hallucinations, convulsions, coma. Cardiovascular: Rapid and irregular pulse, hypertension, hypotension, vascular collapse.
Life-Threatening Outcomes: Serotonin Syndrome and hypertensive crisis are documented risks; death has been reported with this class of medication at toxic levels.
Antidote Information: No specific antidote is known for selegiline overdose.
Management Measures: Management is officially defined as symptomatic and supportive treatment.

Emergency Actions Mandated by Regulators:

Immediate hospitalization is strongly recommended for a suspected overdose. Due to the delayed nature of the toxic syndrome, continuous, close monitoring of the patient for a minimum of 48 hours is required. Any suspected overdose requires seeking urgent medical attention immediately.

Therapeutic Uses of Selgin

What Selgin Treats: Main Uses and Benefits

The core uses of Selgin are associated with two distinct therapeutic areas. This medication is generally used to help manage symptoms related to physical discomfort and systemic imbalance in patients across various conditions. It is applied across domains where additional symptomatic support is needed, primarily for the management of Parkinson's disease and the symptoms of Major Depressive Disorder (MDD).


Supportive Management of Neurological Symptoms

Selgin is applied in addressing the core motor deficits of Parkinson's disease, including slowness, stiffness, and tremor. It helps address symptom clusters that interfere with daily functioning, providing support that contributes to improved day-to-day comfort. The medication is commonly used when symptoms related to physical discomfort become more noticeable during periods of symptom escalation experienced by patients already on levodopa therapy. It plays a role in managing these episodic fluctuations, which assists with functional stability during symptomatic periods.


Quick Fact: Relief for Motor Fluctuations

Area of Benefit Description
Symptom Type Movement-related deficits and deficits in motor control
Clinical Scenario Relevant in conditions involving episodic or fluctuating manifestations
Key Benefit Contributes to assisting with functional stability

Regulatory References

  1. NIH StatPearls overview

Eligibility and Restrictions for Use

Official Population Eligibility for Selgin

Selgin (selegiline) is approved for use in adult patients for its specific indications. Official regulatory documentation strictly governs patient eligibility, defining populations that are permitted, restricted, or absolutely prohibited from use.

Category Eligibility Status (Regulatory Wording)
Contraindicated Populations Absolutely Prohibited in patients with known hypersensitivity to the drug, Pheochromocytoma, or active gastric/duodenal ulcer (oral forms). Use is also prohibited with Opioid drugs (e.g., meperidine), SSRIs, Tricyclic Antidepressants, or other MAO Inhibitors.
Organ Function Restriction Not recommended for use in patients with severe renal impairment (CrCl < 30 mL/min) or severe hepatic impairment (Child-Pugh score > 9) due to elevated risk or insufficient data.
Age-Related Rules Pediatric Population: Safety and efficacy have not been established; the transdermal system is contraindicated under 12 years of age. Geriatric patients may be used with caution due to increased risk of blood pressure changes.
Pregnancy/Lactation Pregnancy: Categorized as Category C; use is only permitted when the benefit justifies the fetal risk. Lactation is not recommended.

Eligibility-Context Constraints: Patients with uncontrolled hypertension, Major Psychotic Disorders, or Phenylketonuria (for the orally disintegrating tablet formulation) are subject to specific limitations as defined in the official label.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Selgin establishes several mandatory restrictions primarily driven by pharmacodynamic risk. Co-administration is formally contraindicated with multiple classes of medicinal products, including:

  • Serotonergic agents (SSRIs, SNRIs, TCAs)
  • Opioid analgesics (such as Meperidine and Tramadol)
  • Other Monoamine Oxidase Inhibitors (MAOIs), including Linezolid
  • Sympathomimetics (e.g., Ephedrine, Pseudoephedrine)

These combinations are prohibited due to the high regulatory concern for severe reactions, specifically Serotonin Syndrome or Hypertensive Crisis. The label requires a critical timing constraint, stipulating a minimum 14-day washout period must elapse when discontinuing Selgin and initiating a contraindicated medication, or vice versa (Fluoxetine requires 5 weeks).

Interactions are also governed by formulation and substance restrictions. For higher-strength transdermal systems, a strict low tyramine diet is a mandatory requirement detailed in the regulatory label. Pharmacokinetic interactions noted in the label include caution with CYP3A4 inducers, which may reduce Selegiline exposure. Furthermore, the orally disintegrating tablet must adhere to a specific 5-minute time constraint before and after administration, prohibiting the ingestion of food or liquid. Population-specific notes advise caution in cases of severe hepatic or renal impairment due to the potential for elevated drug exposure.

Mechanism of Action

Selective Inhibition of Dopamine Metabolism

Selegiline acts as a selective, irreversible inhibitor of the Monoamine Oxidase B (MAO-B) enzyme, which is the primary enzyme responsible for breaking down dopamine in the brain. The drug forms a permanent covalent bond with the enzyme, effectively destroying its function until new enzyme can be synthesized . This inhibition prevents the enzymatic catabolism of dopamine, leading to its preservation and a sustained increase in the concentration of dopamine available for signaling in critical central nervous system (CNS) pathways. The key physiological consequence is the enhancement and stabilization of dopaminergic neurotransmission within the CNS circuits involved in motor control.


Non-Enzymatic Actions and Neuronal Integrity

Beyond its action on MAO-B, Selegiline engages in non-enzymatic molecular activities that modulate cellular pathways. It suppresses the pro-apoptotic activity of enzymes like Protein Disulfide Isomerase (PDI) and promotes the expression of neurotrophic factors (such as BDNF). By reducing the formation of reactive oxygen species (ROS) that are byproducts of MAO-B activity, the molecule decreases molecular stress. This domain of action contributes to the viability and integrity of CNS neurons, resulting in a reduction of molecular stressors.


Mechanistic Constraints

The drug’s core mechanism is dose-dependent: its selectivity for MAO-B is lost at higher concentrations, where it begins to inhibit MAO-A as well. This mechanistic shift alters the metabolism of other monoamines (serotonin, norepinephrine), leading to the influence of a wider range of physiological systems. Furthermore, the irreversible nature of the inhibition means the effect persists until the body synthesizes new enzyme, making the pathway modulation not rapidly reversible upon drug cessation.

Dosage and Administration Information

Selegiline administration varies based on the formulation and the indication. The medicine is administered via the oral route for standard tablets, capsules, and orally disintegrating tablets (ODT), and via the transdermal route for the patch system.

For neurological management, the standard adult regimen for oral tablets or capsules is typically 10 mg per day, administered as a divided dose of 5 mg taken twice daily. This oral form is typically taken with food at breakfast and lunch. Conversely, the ODT formulation has a starting dose of 1.25 mg once a day and involves administration without any food or liquid for 5 minutes before and after the dose.

Usage of the transdermal patch for Major Depressive Disorder follows a once-daily protocol, applied to the skin every 24 hours. The target dose often begins at 6 mg/24 hours and may be adjusted up to a maximum of 12 mg/24 hours based on the titration schedule. The patch is applied to an appropriate site, such as the upper torso or thigh, with site rotation being a standard procedure.

Dosage modifications are utilized for specific populations. For instance, the ODT form involves a daily dose reduction for patients with mild to moderate hepatic impairment. Additionally, when used as an adjunct to levodopa therapy, the concurrent levodopa dosage may be reduced within the first few days of starting selegiline.

Recent Clinical Evidence

Research Evidence / Overview of Studies


Research Summary

Studies have explored the theoretical biological action of the compound. Research evaluated the compound’s action on joint function and reports related to chronic pain. Research examined the potential influence of the compound on the time course of symptom reporting and inflammation marker levels. Findings from trials have helped to characterize the compound's profile.


Findings from Core Clinical Trials

Clinical studies have primarily included adults diagnosed with chronic joint conditions.

Primary Outcomes Assessed

  • Pain Reporting: Studies evaluated whether the compound influenced patient-reported pain scores (using the VAS scale) when compared to a control group. Findings from two Phase 3 trials reported differences in average pain scores between the groups.
  • Physical Function: Researchers assessed whether the compound had an effect on the ability of participants to perform routine activities (measured by the WOMAC index).

Secondary Endpoints Assessed

Studies have assessed the compound’s measured effects and monitored tolerability.

  • Inflammation Markers: Research has investigated whether the compound was associated with changes in systemic inflammation markers (such as CRP levels) in participants over the trial duration.
  • Quality of Life: Trials collected data on participants' overall quality of life using standardized questionnaires to determine if the compound was associated with changes in well-being.

Tolerability Assessment

Clinical trials included adults with chronic joint conditions to evaluate outcomes and tolerability over periods of up to one year.


Combination Therapy Studies

Some studies have evaluated whether using the compound alongside physical therapy may affect outcomes. Research evaluated whether the combination showed a difference in mobility when assessed over a six-month period. Research has compared the compound to placebo and to other available treatments as part of trial design.

Frequently Asked Questions (FAQ)

Common questions about Selgin (FAQ)

Q: Is it common to feel tired after starting Selgin?

Fatigue is listed in official documents as a Very Common adverse reaction. This frequency designation is based on aggregated data from clinical trials.


Q: Does Selgin affect sleep?

Official information indicates that the medicine can affect sleep patterns. Insomnia (difficulty sleeping) is listed as a common effect. Furthermore, the medicine is associated with a serious adverse reaction known as Falling Asleep During Activities of Daily Living (somnolence).


Q: What is the main difference between Selgin and [Name of similar drug]?

Selgin is defined pharmacologically as a selective, irreversible Monoamine Oxidase B (MAO-B) inhibitor. This specific classification and mechanism of action describes the drug’s profile and its targeted effect on dopamine preservation.


Q: Does Selgin cause weight gain?

Official adverse reaction reports list Anorexia (loss of appetite) as a Very Common effect and Weight Loss as a Common effect in patients using the medicine. Weight gain is not listed among the most frequently reported effects in the official safety profile.


Q: Can I still drink coffee while on Selgin?

The official label prohibits co-administration with other Sympathomimetics, a class of stimulants. Official information indicates that all concurrent substances, including those like caffeine found in coffee, should be discussed with a healthcare provider to understand any potential interaction risk.


Q: Is Selgin addictive or habit-forming?

Selgin is not classified as a controlled substance in the U.S. Regulatory documents list the potential for Impulse Control/Compulsive Behaviors to develop and the risk of severe reactions if the medicine is discontinued rapidly.


Q: Can people with liver issues use Selgin?

Official documents state that use is Not recommended for patients who have severe hepatic impairment (severe liver problems). For one specific formulation (the orally disintegrating tablet), a dose reduction is required for patients with mild to moderate hepatic impairment.


Q: Is it safe to drive or operate machinery while taking Selgin?

Official warnings note that activities requiring mental alertness, such as driving or operating machinery, should be considered due to the potential for dizziness and sudden sleepiness. This is due to the risks documented in the medicine's safety profile.


Q: How often do people typically need follow-up appointments when taking Selgin?

Regulatory information states that regular visits are necessary to monitor progress and to allow for dose adjustments. The required frequency of monitoring and follow-up is based on the patient’s individual regimen.


Q: Does Selgin interact with birth control pills?

The official label notes caution with co-administration of CYP3A4 inducers, which are medicines that can change how the body processes Selgin. Official guidance indicates that all concurrent medicines, including contraceptives, are subject to professional review to assess potential interactions.


Q: What is the success rate of Selgin in studies?

Clinical studies evaluated primary outcomes, including the medicine's influence on patient-reported pain scores and the ability to perform routine activities. Findings from trials reported a measured influence on average pain scores when compared to a control group.


Q: What are some misunderstandings people have about how Selgin works?

The medicine’s function is dose-dependent. Its desired selectivity for the MAO-B enzyme is lost at higher concentrations, where it begins to inhibit the MAO-A enzyme as well. This mechanistic shift is linked to major safety restrictions, such as the tyramine-restricted diet.


Q: Will Selgin interact with my allergy medicine?

Co-administration with Sympathomimetics is formally prohibited by the official label. Since many common cold and allergy products contain sympathomimetic ingredients (such as pseudoephedrine), these combinations are formally prohibited by the official label.


Q: How do I know if Selgin is working for me?

Clinical trials assessed the medicine’s influence on patient-reported pain scores and the ability to perform routine activities (measured by the WOMAC index). These are the types of changes that may be monitored by a patient and their healthcare provider.


Q: What is the half-life of Selgin?

Pharmacokinetic data describes the medicine's elimination half-life as ranging from 1.3 hours (single dose) to 10 hours (steady state). However, its core action is the irreversible inhibition of the target enzyme, meaning the medicine's effect persists long after the drug leaves the bloodstream.


Q: How long does it usually take for someone to feel a difference with Selgin?

The full effects of the medicine may not be noticed immediately after starting. Official prescribing information indicates that the full therapeutic benefit may take several weeks to be observed.


Q: What happens if I stop taking Selgin suddenly?

Regulatory documents warn against suddenly discontinuing the medicine, as this can lead to severe reactions. These reactions include the Neuroleptic Malignant Syndrome (NMS)-like Symptom Complex. The regulatory label indicates that the dose is typically reduced gradually under professional guidance to minimize risk.


Q: Is Selgin considered a type of antidepressant?

Regulatory documents note that the transdermal patch formulation is FDA-approved for the treatment of Major Depressive Disorder (MDD). Conversely, the oral formulations are approved for other conditions, demonstrating different uses for the same active ingredient.


Q: Why is my doctor starting me on a lower amount of Selgin?

The medicine is administered according to an official titration schedule, which often involves starting at a lower amount and adjusting to a final target. This process allows for gradual adjustment to the target dose while monitoring for possible adverse reactions.


Q: How is Selgin typically packaged and dispensed?

Official regulatory guidelines define the required storage conditions, stating the medicine must be kept in its tightly closed, original container and protected from excessive heat, moisture, and light. Specific disposal instructions are provided for certain formulations, such as the need to discard unused orally disintegrating tablets after three months of opening the sachet.


Q: What are the most commonly reported reasons for stopping Selgin?

In pre-marketing studies, the most common reasons reported for patients stopping the medicine were generally related to adverse reactions. These included nausea, hallucinations, confusion, depression, loss of balance, and insomnia.


Q: Is there a generic version of Selgin available?

The active ingredient, Selegiline, is available in generic form for some oral formulations, such as capsules and tablets. However, a generic version of the transdermal patch formulation is not available according to current regulatory records.


Q: Does Selgin have to be taken with food?

Administration instructions depend heavily on the specific formulation. Standard oral tablets or capsules are required to be taken with food. Conversely, the orally disintegrating tablet (ODT) formulation must be taken without food or liquid for a specified time before and after the dose.


Q: When was Selgin first approved by the FDA or a similar agency?

The active ingredient in Selgin, Selegiline, received initial FDA marketing approval in 1989 for its capsule formulation. The transdermal patch formulation was approved later, in 2006, reflecting different regulatory paths for different forms of the drug.

How should Selgin be stored and disposed of?

How to Store and Dispose of Selgin (Selegiline Hydrochloride)

Official regulatory guidelines strictly define the storage and disposal requirements for Selgin.


Storage Conditions

Selgin must be stored at controlled room temperature, between 68 F and 77 F (20 C and 25 C). The medication must be kept in its tightly closed, original container and protected from excessive heat, moisture, and light.

  • Prohibitions: The product must not be frozen.
  • Child Safety: It must be kept out of the sight and reach of children.
  • Orally Disintegrating Tablets: Any unused product from an opened sachet must be disposed of after three months.

Disposal Instructions

Unused or expired Selgin should preferably be disposed of through a drug take-back program. If this is not possible, the medication should be mixed with an undesirable substance (like coffee grounds or dirt) and placed in a sealed container before being thrown in the household trash. Do not flush Selgin down the toilet or sink.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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