Мисолин

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Мисолин

Medically reviewed

Laura Arias

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 Мисолин

Property Description
Active ingredient Primidone
Form Oral Tablet
Pharmacological class Anticonvulsant (Antiepileptic Agent)
Common purpose Stabilizing neurological electrical activity
Origin Synthetic; Barbiturate derivative

What is the Composition and Origin of Мисолин (Primidone)?

Мисолин is a medication containing the active ingredient Primidone, which is a synthetic compound classified as a barbiturate derivative. It is supplied as a single-ingredient product in an oral tablet form, intended for systemic effect via the oral route. Primidone is particularly unique because the body actively metabolizes a portion of the original compound into two other active substances, phenobarbital and phenylethylmalonamide (PEMA), a pathway clinically recognized for broadening the overall anticonvulsant effect.

What Type of Medicine is Мисолин Classified as?

Мисолин is formally classified within the high-level pharmacological class of Anticonvulsants, making it an Antiepileptic Agent. This designation is given to medicines used to stabilize states of abnormal electrical activity in the central nervous system. Its chemical structure as a barbiturate derivative (or first-generation antiepileptic) distinguishes it from newer agents, placing it within a foundational group of compounds supported by decades of pharmacological studies. This classification confirms the drug's core functional identity: to manage nerve cell hyperexcitability.

What is the General Therapeutic Purpose of Anticonvulsant Agents?

The general therapeutic purpose of an anticonvulsant like Мисолин is to manage and prevent abnormal, recurring electrical discharges within the central nervous system. By acting to modulate the excitability of nerve cells and supporting inhibitory signals, the medicine serves to counteract the underlying physiological basis for neurological instability. The goal of using a compound like Primidone is to achieve a protective neurophysiological state where the brain is less susceptible to uncontrolled electrical events, thereby establishing and sustaining a more balanced environment for neuronal communication.

Regulatory References

  1. Source: NIH LiverTox

What side effects are possible with Мисолин?

Possible Side Effects and Safety Information

This section outlines the officially documented adverse reactions and regulatory safety constraints for Primidone (Мисолин), based on government regulatory labeling.

Frequency and Common Adverse Reactions

Adverse reactions are classified by how often they occur. The most frequently occurring side effects, especially at the start of therapy, are related to the nervous system and often decrease with continued use. These commonly include ataxia (loss of coordination), vertigo, drowsiness, and nausea.

Classification Examples of Documented Side Effects
Most Common Ataxia, Vertigo, Drowsiness, Listlessness
Common Nausea, Nystagmus, Visual disturbances
Uncommon Headache, Dizziness, Hyperirritability

Serious Adverse Reactions and Systemic Risks

Regulatory documents highlight rare but serious risks that may require immediate attention:

  • Severe Cutaneous Adverse Reactions (SCARs): These include rare, life-threatening skin reactions such as Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).
  • Hematologic Abnormalities: Rare occurrences of blood disorders such as megaloblastic anemia and agranulocytosis have been reported.
  • Psychiatric Risk: As with all anti-epileptic drugs, the risk of suicidal thoughts or behavior is documented.
  • Long-Term Effects: Osteomalacia (softening of the bones) and decreased bone density are associated with long-term therapy.

Safety Constraints and Special Populations

Contraindications include known hypersensitivity to Primidone or barbituric acid derivatives, and a history of acute intermittent porphyria.

  • Pregnancy and Childbearing Potential: The drug is associated with specific risks during pregnancy, including an elevated incidence of birth defects and neonatal hemorrhage. Use in women of childbearing potential necessitates the use of highly effective contraception, as Primidone may reduce the effectiveness of hormonal birth control.
  • Monitoring: Regular monitoring of complete blood count and other key lab values is recommended for patients on long-term treatment.

Overdose and Emergency Response

Overdose and When to Seek Help

This section details the officially documented signs of overdose with Мисолин (Primidone) and the required help-seeking actions, based strictly on government regulatory sources.

Documented Overdose Manifestations

Overdose with Primidone, a drug that is partly metabolized into phenobarbital, is associated with the risk of significant central nervous system (CNS) and respiratory depression. Regulator-derived information notes the following clinical signs:

  • Central Nervous System Effects: Confusion and potential progression to coma.
  • Ocular/Visual Effects: The appearance of double vision and continuous, uncontrolled rolling eye movements.
  • Respiratory Effects: Experiencing troubled breathing.

Required Emergency Actions

Due to the potential for severe, life-threatening outcomes, including respiratory failure, immediate emergency action is mandated in official prescribing information:

Required Action Description (Label-Derived Phrasing)
Immediate Contact Call your healthcare provider or local Poison Control Center right away.
Urgent Care Seek immediate medical help if any suspected overdose or symptom like troubled breathing occurs.

Management and Considerations

There is no specific antidote available for Primidone overdose. Treatment is primarily symptomatic and supportive, focused on maintaining vital functions. While not distinct manifestations, regulatory caution is advised for use in elderly or those with impaired renal, hepatic, or respiratory function, suggesting increased vulnerability to toxicity should an overdose occur.

Therapeutic Uses of Мисолин

Control of Chronic Epileptic Seizure Patterns

Мисолин is commonly used in conditions characterized by periods of heightened symptoms related to epilepsy, with its use applicable in addressing clinically relevant seizure types including generalized tonic-clonic seizures, complex partial seizures, and various focal epileptic seizures. This medication is considered relevant in clinical settings that involve acute or unstable symptom patterns, and may assist with managing symptoms of increased neurological activity that create noticeable physiological strain. The primary therapeutic benefit may be supportive in reducing the recurrence of seizures, which supports general well-being during symptomatic phases.


Symptomatic Relief for Essential Tremor

This medication is applied across domains where additional symptomatic support is needed for Essential Tremor (Familial Tremor). This involves addressing symptom clusters that may become intense or disruptive, specifically the persistent involuntary shaking that interferes with daily functioning. Мисолин is commonly used to help with managing symptoms that create noticeable functional strain. It may assist with maintaining functional stability and helps improve day-to-day comfort during symptomatic periods.

“The therapeutic role is relevant across domains where additional symptomatic support is needed for recurrent, disruptive neurological events.”

Quick Fact: Supportive Management for Involuntary Shaking Мисолин is considered relevant for managing the persistent, disruptive shaking associated with Essential Tremor, may help with managing the effect on daily activities.

Eligibility and Restrictions for Use

Population Eligibility Rules for Мисолин (Primidone)

Official regulatory documents define strict criteria for who is eligible to use Мисолин. The medicine is approved for use in adults and children 8 years of age and older for the control of grand mal and psychomotor seizures. Safety and efficacy in children under 8 years of age have not been established by certain authorities.


Absolute Contraindications

Мисолин is formally contraindicated in patients with a history of Porphyria and in those with known hypersensitivity or allergic reactions to Primidone or to its active metabolite, Phenobarbital. Use is also prohibited in patients with severe respiratory depression or certain conditions like sleep apnea.


Conditional Use and Restrictions

Use of the medicine requires specific caution and reduced dosing in older adults and debilitated patients. Eligibility is restricted for those with hepatic impairment (liver disease) or renal impairment (kidney disease). During pregnancy, Мисолин is classified as Pregnancy Category D by the FDA, indicating positive evidence of human fetal risk, and is generally not recommended unless necessary. For nursing mothers, a decision must be made to discontinue nursing or discontinue the drug, as it passes into breast milk.

What should I know about interactions with other medicines?

The active substance of Мисолин (Primidone) is a known strong inducer of hepatic enzyme metabolism, primarily the Cytochrome P450 3A4 (CYP3A4) system and UGT enzymes. This effect accelerates the breakdown and clearance of many co-administered medicinal products, which can lead to clinically significant decreases in their blood concentrations and potential loss of therapeutic effect.

Documented Interactions

Classification Interacting Product Category/Specific Examples
Contraindicated Strong CYP3A4-metabolized antivirals (e.g., Atazanavir, Fostemsavir, Lenacapavir, Elbasvir/Grazoprevir); Antifungal agents (e.g., Voriconazole); and certain Hormonal Contraceptives (e.g., Estradiol Valerate/Dienogest).
Use with Caution Anticoagulants (e.g., Warfarin); other Anticonvulsants; Antimalarials (e.g., Artemether/Lumefantrine); and other CNS Depressants, including alcohol.

Co-administration with other CNS depressants increases the risk of enhanced sedation, dizziness, or respiratory depression. Because of its enzyme-inducing properties, Primidone can reduce the efficacy of oral hormonal contraceptives; a highly reliable, non-hormonal method of contraception is generally recommended. Use with herbal products, such as St. John's Wort, may also decrease the Primidone concentration. Furthermore, Primidone is documented to affect the metabolism of Vitamin K and Folate, requiring attention, particularly in certain patient populations.

Mechanism of Action

How Мисолин works — Mechanism of Action

Мисолин exerts its effects primarily through the targeted modulation of specific receptor systems located in [Tissue/System]. The drug functions as a [specific interaction type], engaging [Receptor Type] to directly modify its activity. This molecular-level interaction serves as the critical initiation point for the drug’s pharmacodynamic profile.

Following the initial receptor binding, a defined mechanistic cascade is triggered. This sequence involves the alteration of [Intracellular Mediator] activity, which modulates the subsequent flow of information through the [Specific Signaling Pathway]. This action is concentrated on pathways associated with [Type of Signaling] dynamics.

Collectively, the molecular and intracellular effects lead to the system-level physiological consequence of Мисолин. The drug contributes to the adjustment of overall activity within the targeted neural or humoral pathways and reduces the presence or functional activity of specific mediators. This action results in a predictable modulation of the [Physiological Function] system, shaping the drug’s effect profile without referencing clinical outcomes.

Dosage and Administration Information

How to use Мисолин (Primidone) — Official Administration Guidelines

Мисолин (primidone) is administered orally. Dosing requires a gradual increase (titration) over a period of days to weeks, which is essential for minimizing initial effects and achieving a proper maintenance dose. The tablets should be swallowed whole with a glass of water.

Administration is generally in divided doses taken at regular intervals, often twice daily, unless directed otherwise by a healthcare provider. Taking the medication with food is permissible and may help minimize gastrointestinal irritation.

Official Dosing Schedule

For adults and children 8 years of age and older who are starting treatment, the initial regimen involves a progressive increase in dosage. Treatment often begins with 100 to 125 mg once daily at bedtime for the first 3 days, followed by structured increases in frequency and amount over the subsequent 6 days. The usual adult maintenance dose is 250 mg three to four times a day, with a maximum daily dose not to exceed 2 g.

Age Group Days 1–3 Days 4–6 Days 7–9 Maintenance Dose Max Daily Dose
≥ 8 Years 100–125 mg at bedtime 100–125 mg twice daily 100–125 mg three times daily 250 mg three to four times daily 2 g
< 8 Years 50 mg at bedtime 50 mg twice daily 100 mg twice daily 125–250 mg three times daily 2 g

Missed Dose Instructions

If a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the patient should return to the regular dosing schedule. Double doses must not be taken to make up for a missed dose.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Мисолин

Evidence for use in Controlling Chronic Epileptic Seizure Patterns

Мисолин (Primidone) was studied in research exploring specific types of epileptic seizures, including generalized tonic-clonic and certain focal epileptic seizures. The evidence base includes foundational randomized controlled trials (RCTs) and extensive long-term observational studies. Studies monitored outcomes such as seizure frequency and the proportion of participants with sustained periods without recorded seizures over a defined time interval. Findings describe patterns where some study participants had sustained periods without recorded seizures. However, comparative evidence is lacking in terms of modern, head-to-head RCTs against all of the newer antiepileptic agents.


Evidence for use in Symptomatic Relief for Essential Tremor

The compound was evaluated in research for conditions associated with acute or disruptive episodes like Essential Tremor (ET). The research framework includes randomized, double-blind, placebo-controlled trials and systematic reviews. These studies monitored outcomes reflecting daily functioning, such as the physical measurement of tremor amplitude and scores on specialized functional scales. Systematic reviews described observed measurements when the compound was evaluated in trials. Studies also noted that a proportion of participants discontinued the study early, which impacted long-term follow-up.


Research Gaps and Limitations

The research highlights several areas where more information is needed. Long-term effects are not fully established by large-scale, prospective controlled trials, as follow-up durations were limited in the initial efficacy studies. Data for specific groups, such as children with epilepsy, is available, but the results apply only to the populations studied, and the interpretation of these findings requires careful context. Furthermore, comparative evidence is lacking for many direct comparisons against newer therapeutic options. Research remains ongoing to fill these existing gaps.

Key Studies & References Primidone - LiverTox: Clinical and Research Information on Drug-Induced Liver Injury

Frequently Asked Questions (FAQ)

Common questions about Мисолин (FAQ)


Q: What is the main reason doctors prescribe Мисолин?

According to official product information, Мисолин is primarily prescribed for the management and control of epileptic seizures, specifically including generalized tonic-clonic and certain focal seizures. It is approved to be used either alone or in conjunction with other anti-seizure medicines to help stabilize neurological activity.


Q: Is Мисолин the same thing as other similar medicines for this condition?

Мисолин (Primidone) is classified as an anticonvulsant medicine, which is a class that includes many different drugs. While it is chemically distinct, a key part of its action comes from its major metabolite, phenobarbital, which is another anticonvulsant. Therefore, while similar in its overall effect, Мисолин is a unique compound with its own profile.


Q: Why do people say Мисолин helps with more than just its main use?

Official information indicates that while the primary use of Мисолин is for seizures, it has also been evaluated in clinical research for other neurological conditions. It may also be prescribed for symptomatic relief of Essential Tremor, a condition characterized by uncontrollable shaking. This represents another documented therapeutic area for the medicine.


Q: How long does it typically take to feel the effect of Мисолин?

While the medicine reaches its peak blood concentration in about four hours after a dose, reaching the full therapeutic effect may take longer. Official guidelines recommend a gradual increase in dosage over several weeks. Therefore, it may take this period of gradual adjustment to assess the full therapeutic effect.


Q: Can Мисолин make you feel tired or sleepy during the day?

Yes, regulatory documents list drowsiness and listlessness as common adverse effects associated with Мисолин, especially during the initial phase of treatment. The administration guidelines often describe taking the initial dose at bedtime. These effects frequently lessen as the body adjusts to the medication.


Q: Are there any common foods or drinks that should be avoided with Мисолин?

Official warnings state that the consumption of alcohol with Мисолин is discouraged, as this can enhance central nervous system (CNS) depressant effects, potentially leading to increased sedation, dizziness, or respiratory issues. No specific foods are routinely contraindicated in the official labeling.


Q: Is it possible to become dependent on Мисолин?

As a derivative of the barbiturate class, regulatory warnings state that prolonged use of Мисолин carries a potential for physical dependence. Official guidance indicates that treatment should not be stopped suddenly. Instead, it must be withdrawn gradually under medical guidance to avoid potential withdrawal reactions.


Q: Does Мисолин interact with common pain relievers?

Official drug interaction information indicates that Мисолин is an enzyme inducer. This means it can speed up the way the body breaks down other drugs, including some common pain relievers like acetaminophen. This may result in reduced concentrations of the pain reliever and, particularly with regular or high doses, may carry a risk of liver toxicity.


Q: Is it normal to feel a little dizzy when first taking Мисолин?

Yes, regulatory data indicates that it is common and expected to experience nervous system effects, such as dizziness and a sensation of spinning (vertigo), when initiating treatment. These effects often occur because the body is adjusting to the medication and typically resolve or lessen over the first few weeks of therapy.


Q: What are the signs that a person might be having a known allergic reaction to Мисолин?

Official warnings describe when immediate medical attention is necessary, such as if signs of a severe allergic reaction occur. These signs include swelling of the face, lips, tongue, or throat. Official warnings also describe the appearance of a severe, progressive skin rash (often with blisters or mucosal lesions) as a concern.


Q: What happens if I stop taking Мисолин suddenly?

Regulatory documents explicitly warn against the abrupt cessation of Мисолин. Stopping the medication suddenly can carry a serious risk of withdrawal symptoms or precipitating prolonged or repeated seizures, known as status epilepticus. Changes to treatment are generally described as needing to be done gradually and under the direction of a healthcare provider.


Q: Does taking Мисолин affect the ability to concentrate?

Yes, official warnings caution that Мисолин can cause side effects that impair cognitive function. These effects include drowsiness, dizziness, and problems with coordination. These known effects can negatively impact a patient's judgment, reaction time, and ability to concentrate.


Q: What is the difference between the immediate-release and extended-release versions of Мисолин, if they exist?

The most widely approved formulation of Мисолин is the standard oral tablet form, which is intended for multiple daily administrations. Regulatory documents describe the pharmacokinetics of this standard form but do not list or provide comparative information for an officially approved extended-release version of the medication.


Q: What is the typical experience people have when starting Мисолин?

To minimize initial effects, the administration schedule typically starts with a low dose taken at bedtime and involves a gradual increase. The most typical initial experiences are related to the central nervous system, which may include feeling drowsy, dizzy, or experiencing ataxia (clumsiness), which often improves over time.


Q: Are there any reports of long-term side effects from Мисолин?

Official regulatory warnings acknowledge specific risks associated with long-term therapy using Мисолин. These documented risks include a potential decrease in bone density and the development of osteomalacia (softening of the bones), as well as rare occurrences of certain blood disorders.


Q: Is it true that Мисолин can affect mood?

Yes, official product information indicates that like all anti-epileptic drugs, Мисолин carries a documented risk of potentially causing or worsening suicidal thoughts or behavior. Changes in emotional state, including the emergence or exacerbation of depression and anxiety, may also occur.


Q: Does Мисолин interact with medication for high blood pressure?

Yes, Мисолин is an enzyme inducer, meaning it can affect the levels of other medicines in the body. Because of this, it may alter the blood concentrations of various co-administered medications, including some used to treat high blood pressure (antihypertensive agents). These potential interactions are described in official documents as requiring caution and monitoring.


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

Official warnings describe that patients should avoid driving or performing hazardous tasks that require mental alertness until they fully understand how the medication affects them. This caution is necessary due to the risk of side effects like drowsiness, dizziness, and impaired coordination.


Q: What have patient studies generally concluded about Мисолин?

Clinical trial summaries indicate that Мисолин has shown an effect in controlling and reducing the frequency of epileptic seizures. Furthermore, in studies concerning Essential Tremor, the compound demonstrated an ability to improve symptoms for some of the patients evaluated.


Q: How is the need for continued treatment with Мисолин usually determined?

The decision for continued treatment with Мисолин is determined by the individual patient's sustained response to the medication over time. Because the dose is adjusted gradually, the full therapeutic effect may take several weeks to assess. Monitoring blood concentrations can also be used as a guide for ongoing therapy.


Q: Can men and women expect different effects from Мисолин?

Official documentation does not specifically differentiate the general expected effects or efficacy in adult men versus women. However, there are explicit warnings for women of childbearing potential concerning potential risks during pregnancy and the risk of reduced effectiveness of hormonal contraceptives.


Q: Is the tiredness caused by Мисолин similar to other sedating drugs?

Regulatory information classifies Мисолин as a Central Nervous System (CNS) depressant, which means it has sedating properties. Due to its chemical structure, its sedative actions are similar to those of other barbiturate-derivative anticonvulsants, including its major metabolite, phenobarbital.


Q: Why is it described that Мисолин changes into another substance in the body?

Official pharmacology information notes that Мисолин (Primidone) undergoes metabolism in the body, changing into two other active substances: phenobarbital and phenylethylmalonamide (PEMA). This unique process is clinically recognized as contributing to and broadening the overall anticonvulsant effect of the medication.


Q: How quickly does Мисолин leave the body after the last dose?

The elimination of Мисолин is a multi-step process involving the parent drug and its active metabolites. The half-life of Мисолин itself is approximately 10 to 12 hours. However, its active metabolite, PEMA, has a significantly longer half-life, which can range from approximately 24 to 48 hours.

How should Мисолин be stored and disposed of?

The storage and disposal of Мисолин (Primidone) tablets must adhere strictly to regulatory standards to ensure product stability and public safety.

Storage Requirements

The tablets must be stored at controlled room temperature, specifically maintained between 20 C and 25 C (68 F and 77 F). The container must be kept tightly closed to protect the medicine from environmental factors and avoid excessive heat. As a general rule for all prescription medicines, the product must be kept out of the sight and reach of children.

Disposal Instructions

Unused or expired Мисолин should be disposed of using an authorized drug take-back program. If a take-back option is not available, the tablets should be mixed with an unappealing substance, placed in a sealed container, and discarded in the household trash. The medicine must not be flushed down the toilet or sink, as it is not listed on the FDA flush list for immediate disposal.

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

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