Hepai

Quick links to important sections

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Hepai

Quick Facts

Property Description
Active ingredient Leflunomide
Form Tablet (Oral dosage form)
Pharmacological class Disease-Modifying Antirheumatic Drug (DMARD), Immunosuppressive drug
General purpose Long-term control of chronic inflammatory arthritis
Origin Synthetic, Isoxazole derivative

Hepai: Defining a Specialized Immunosuppressive DMARD

Hepai, a brand name for the active substance Leflunomide, is classified as a synthetic, prescription-only medication belonging to the group of Disease-Modifying Antirheumatic Drugs (DMARDs). This medication is also formally categorized as an Immunosuppressive agent due to its targeted action on the immune system. The active component, Leflunomide, is chemically defined as an Isoxazole derivative and functions as a Prodrug, meaning it converts rapidly into its primary active metabolite, A77 1726 (or Teriflunomide), after oral administration. The United States Food and Drug Administration (FDA) approved this medicine as a DMARD.

Composition and Physical Form of Hepai

Hepai is manufactured as a single active ingredient product, containing only the compound Leflunomide. It is consistently supplied as an oral dosage form, specifically a film-coated tablet. The availability of Hepai exclusively as an oral tablet ensures a predictable and convenient method for sustained therapy, which is a key consideration for long-term patient adherence to a foundational treatment. The composition involves the active agent combined with necessary tablet excipients (base/vehicle) for stable delivery.

General Purpose of this Immunomodulatory Therapy

The general purpose of Hepai is to provide long-term systemic control over the underlying pathology of autoimmune conditions. The drug achieves an immunomodulatory effect by targeting and restricting the rapid expansion of specific immune cells, such as T-lymphocytes, which drive the destructive inflammation. This action classifies the drug as a pyrimidine synthesis inhibitor. The therapeutic goal is to slow disease progression and manage chronic inflammatory activity in conditions like Rheumatoid Arthritis and Psoriatic Arthritis.

What side effects are possible with Hepai?

Possible Side Effects and Safety Information

The safety profile for Hepai is structured based on classifications established by government regulatory bodies. Adverse reactions are grouped by frequency and the body's systems, with most commonly reported effects involving the Nervous System and Gastrointestinal Disorders.

Frequency-Classified Adverse Reactions

Common reactions (occurring in 1% to 10% of individuals) typically include headache, fatigue, dizziness, and nausea.

Uncommon reactions (occurring in 0.1% to 1%) have been documented to include effects on the Skin and Subcutaneous Tissue, such as alopecia (hair loss) and urticaria (hives).


Documented Serious Safety Concerns

Official labeling includes explicit warnings regarding serious, life-threatening safety concerns associated with this class of medicine:

  • Lactic Acidosis and Severe Hepatotoxicity: A rare, but critical concern is the potential for Lactic Acidosis and severe liver enlargement (Hepatomegaly with Steatosis), which may result in fatal outcomes. Treatment should be suspended if clinical or laboratory findings suggest these conditions.
  • Post-treatment Exacerbation: A notable safety pattern is the risk of Severe Acute Exacerbations of Hepatitis B upon the discontinuation of the medicine. Hepatic function must be monitored closely for several months following cessation of therapy.

Population-Specific Safety Constraints

  • Renal Impairment: Dosage adjustment is officially recommended for individuals with reduced kidney function (creatinine clearance below 50 mL/min), including patients undergoing hemodialysis.
  • HIV/HBV Co-infection: The medicine is generally not recommended for patients with both HIV and HBV who are not also receiving highly active antiretroviral therapy (HAART).
  • Decompensated Liver Disease: Patients with pre-existing advanced liver disease are at a higher risk for serious hepatic adverse events.

The overall official safety profile structures risk by separating common, mild events from rare, critical toxicities and highlights conditional risks tied to a patient's underlying health status or the discontinuation of the required long-term treatment.

Overdose and Emergency Response

Overdose Manifestations and Urgent Actions

The official regulatory documentation for Hepai (Leflunomide) states that an overdose may present with documented clinical manifestations that include diarrhea, stomach pain, extreme tiredness, weakness, pale skin, fast heartbeat, and shortness of breath.

The regulatory profile highlights the risk of life-threatening systemic outcomes associated with severe toxicity. Regulators explicitly warn of severe liver injury, including fatal liver failure, and the risk of myelosuppression (bone marrow suppression) leading to severe reduction in blood cell counts.

Immediate medical attention or calling emergency services is mandated for critical symptoms like collapse, a seizure, trouble breathing, or clear signs of liver distress, such as jaundice (yellowing of the skin or eyes) or dark-colored urine.

Management and Monitoring

No specific antidote is known for this overdose. Consequently, management focuses on an Accelerated Drug Elimination Procedure (washout), typically by administering cholestyramine or activated charcoal to rapidly clear the long-acting active metabolite. Following this mandatory procedure, weekly monitoring of liver function tests and blood counts is required until the levels return to normal.

Therapeutic Uses of Hepai

Quick Facts

  • Hepai is used for the management and care of chronic viral hepatitis, specifically addressing Hepatitis B and C infections.
  • The medication is intended to support the reduction of the viral load in patients.
  • It assists in addressing liver function markers in individuals with chronic infection.

What Hepai treats: main uses and benefits

Hepai is a medication approved for the treatment of specific types of chronic viral hepatitis, including both Hepatitis B and C infections. It is part of the therapeutic domain for antiviral medications designed to manage these chronic conditions. The primary intent of the medication is to help reduce the viral load in affected individuals, which is a key objective in the management of hepatitis.

By helping to control viral activity, Hepai works to support the maintenance of liver health and may be associated with improvements in liver function markers. This therapeutic support is designed to benefit patients who are managing persistent viral infection, where the goal of intervention is to limit the impact of the virus on the liver over time.

Eligibility and Restrictions for Use

Eligibility for Hepai: Official Regulatory Profile

The official regulatory profile for Hepai, based on governmental labeling, defines strict criteria for use across different patient populations, physiological states, and comorbidities.

Classification Population Eligibility Rule
Absolute Contraindication Contraindicated in patients with known hypersensitivity to the active substance or any component of the product.
Age Group Eligibility Use is allowed for adults, adolescents 16 years, and children 2 years of age weighing 10 kg. Use is not established for children under two years old.
Renal Impairment Patients with reduced kidney function (creatinine clearance < 50 mL/min) require dose adjustment according to official guidelines.
Liver Status Patients with decompensated liver disease must be under close monitoring; however, no dose adjustment is required for hepatic impairment alone.
Co-Infection Status Use is not recommended for patients co-infected with HIV and HBV who are not simultaneously receiving Highly Active Antiretroviral Therapy (HAART).
Pregnancy and Lactation Use in pregnancy is conditional on the benefit outweighing the potential risk. Breastfeeding is not recommended during treatment.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Interactions with Hepai (which contains acetaminophen) are primarily defined by two critical constraints documented in official regulatory labeling: preventing an accidental overdose from cumulative exposure and managing an effect on blood coagulation.

Documented Interacting Categories and Products

Interaction Domain Relevant Interacting Products/Category Required Action or Constraint
Cumulative Acetaminophen Exposure Other prescription or over-the-counter medicines containing Acetaminophen (or Paracetamol) Patients must be instructed to identify and avoid concurrent use with all other acetaminophen-containing products to prevent accidental exceeding of the maximum daily dose.
Altered Coagulation Oral Anticoagulants (e.g., Warfarin) Requires close clinical monitoring of coagulation parameters (e.g., International Normalized Ratio, or INR) when treatment is initiated, stopped, or the dose is changed.

Official Profile Summary

The regulatory profile for this product strictly mandates that healthcare providers counsel patients on the necessity of reviewing all other medications for acetaminophen content to ensure total exposure remains safe. The simultaneous use of oral anticoagulants, particularly warfarin, establishes a requirement for a procedural constraint—specifically, the need for increased laboratory surveillance of INR in patients stabilized on anticoagulant therapy. These documented interaction statements structure the product's use by establishing strict avoidance rules for certain co-medications and defining procedural requirements for others.

Mechanism of Action

Hepai, identified as a Hepatitis B virus S antigen transport-inhibiting oligonucleotide polymer (STOPS), acts as an intracellular inhibitor primarily within hepatocytes. Its molecular target is not the viral nucleic acid itself, but rather host cellular proteins. The molecule sequesters multiple host factors, including RPLP1, RPLP2, and GRP78 (HspA5), which are essential host proteins involved in the translation, folding, and stabilization of membrane proteins.

The drug's interaction with these host factors is characterized as a binding and sequestration event. This molecular interaction leads to a functional deficiency of these host factors, disrupting the normal molecular pathway for the expression and proper folding of the Hepatitis B virus surface antigen (HBsAg).

The intracellular consequence is the accumulation of misfolded HBsAg, which triggers an increased rate of ubiquitination and subsequent proteasomal degradation of the viral antigen. This downstream cascade results in a dose-dependent reduction in the intracellular concentration and extracellular secretion of HBsAg. The system-level physiological consequence is the reduction of circulating viral antigen load.

Dosage and Administration Information

How to use Hepai: Official Administration Guidelines

Hepai is an antiviral agent that must be used strictly according to the official instructions provided.


Administration Scope

Usage Rule Official Guideline
Route of Administration Oral administration only.
Standard Adult Dose 300 mg once daily, which is the maximum recommended dose.
Timing in Relation to Meals Tablets may be taken with or without food.
Population Adjustment The dosing interval must be extended for adult patients with moderate to severe renal impairment (CrCl < 50 mL/min). No adjustment is required for hepatic impairment.

Preparation and Schedules

  • Frequency Pattern: The regimen is designed for once daily administration (every 24 hours).
  • Pediatric Dosing: For children two years and older, dosing is body-weight-based (up to 300 mg maximum daily).
  • Preparation: If using the oral powder form, it must be mixed with soft food and administered immediately; it should not be mixed with liquids.
  • Missed-Dose Rule: If a dose is missed, it should be taken as soon as possible that day, but patients must not take more than one dose per day to compensate.
  • Course Duration: Treatment for chronic viral hepatitis is generally considered long-term or indefinite; the optimal duration is not specified in the official instructions.

Resulting Procedural Structure

The official instructions establish a standardized, fixed-daily dose protocol centered on a single oral administration. This protocol features a required, pre-defined modification to the dosing frequency for adult patients with reduced kidney function, ensuring that the usage follows the established parameters. The continuous nature of the dosing reflects its function as a chronic therapeutic agent.

Recent Clinical Evidence

Hepai: Recent Clinical Evidence

This overview summarizes the research conducted on Hepai (Leflunomide), focusing on the study types, the outcomes they measured, and what remains uncertain. This is not medical advice and does not include instructions or safety information.


Research Evidence for Rheumatoid Arthritis (RA)

The research exploring Hepai's study for Rheumatoid Arthritis (RA) includes a large number of randomized controlled trials (RCTs). These short- and intermediate-term trials examined outcomes related to systemic or functional imbalance and physical discomfort. Studies were observed in adult populations with active RA, including those newly diagnosed. Researchers monitored how symptoms evolved and measured changes in functional ability. Some studies also reported how measurements of X-ray evidence (radiographic scores) changed over one to two years of follow-up. Long-term effects are not fully established based solely on initial controlled trials, and results apply only to the populations studied.

Evidence in Psoriatic Arthritis and Other Contexts

Hepai was also studied for Psoriatic Arthritis (PsA) in controlled trials that explored outcomes related to inflammatory states in both joints and skin. However, the overall volume of research evidence for PsA was modest. Furthermore, data are still emerging for specific patient groups, including the pediatric population and individuals with certain complex medical histories. Overall, comparative evidence is lacking against all of the newer treatments, and long-term effects are not fully established for the entire patient population. The results apply only to the populations studied in the research settings.

Key Studies & References

  1. ACR/ARP Guidelines for the Management of Rheumatoid Arthritis
  2. Pharmacological interventions for psoriatic arthritis: a systematic review and meta-analysis of randomized controlled trials (Leflunomide evidence)

Frequently Asked Questions (FAQ)

Common questions about Hepai (FAQ)


Q: Is Hepai a long-term medication?

Official prescribing information indicates that treatment with this medicine for chronic inflammatory conditions is generally considered to be long-term or indefinite. This aligns with its classification as a Disease-Modifying Antirheumatic Drug (DMARD).

However, the optimal duration of treatment is not specified in regulatory labeling, and this decision is made based on individual patient need.


Q: Why is Hepai prescribed to people?

The medicine is officially indicated for the management of the signs and symptoms of active rheumatoid arthritis or psoriatic arthritis in adults. The general goal is to support the improvement of physical function and help slow the progression of structural damage related to the condition.


Q: How quickly does Hepai start to work?

Clinical data indicates that the therapeutic effect of the medicine is typically observed starting around four to six weeks of continuous treatment. Full benefit takes longer to achieve, as the medicine works gradually over time.


Q: What is the expected timeline for feeling the full benefit of Hepai?

Clinical data indicates that following the initial onset of effect, the therapeutic response may continue to improve for up to six months of continuous treatment. This extended timeline is due to its classification as a Disease-Modifying Antirheumatic Drug (DMARD).


Q: Can Hepai affect my sleep?

Official adverse reaction summaries include common reported events such as headache and dizziness. These effects may indirectly influence sleep quality, but the product information does not specifically cite 'sleep disturbance' in the common or uncommon categories.


Q: Is it normal to feel [vague side effect] when starting Hepai?

The official safety profile lists several adverse reactions that are common, meaning they are reported to occur in 1% to 10% of individuals. Commonly reported effects include headache, fatigue, dizziness, and nausea.


Q: Are the side effects of Hepai worse when you first start taking it?

According to official product information, the initial use of a loading dose may be associated with an increased rate of reported adverse events. This suggests that the body’s reaction may be more pronounced when the medicine is first started.


Q: Can Hepai cause weight gain?

Official safety profiles list weight loss as a reported adverse reaction within the uncommon category. Regulatory documentation does not cite weight gain as a common or uncommon adverse reaction.


Q: Are the side effects of Hepai permanent?

The active substance has a long elimination half-life. Due to this, the medicine requires specific medical procedures to ensure it is fully cleared from the body. Some severe effects, like hepatic injury, have been observed to resolve upon discontinuation of the medicine.


Q: Can I use Hepai if I have [unrelated chronic condition]?

Regulatory documents list specific chronic conditions that may require caution or prohibit the use of the medicine. These include conditions such as severe immunodeficiency, significant liver or kidney disease, or certain nerve problems. Eligibility criteria are based on a patient's overall health status.


Q: How long does Hepai stay in your system?

The active substance has a long elimination half-life, reported to be approximately 14 to 18 days. This extended half-life means the medicine requires a planned and managed approach to ensure it is fully cleared from the body.


Q: What are the most common reasons someone stops taking Hepai?

Studies report that the most common reasons patients stopped taking the medicine were experiencing adverse events. The loss or lack of the desired therapeutic effect over time was also a reported factor for stopping the treatment.


Q: Can Hepai be taken with supplements or vitamins?

Regulatory safety information directs patients to inform their healthcare providers of all other medications, including any vitamins, herbal products, or nutritional supplements they may be taking. This instruction is provided due to the potential for interaction risks.


Q: Does taking Hepai change how I feel day-to-day?

The official safety profile includes common reported adverse events such as fatigue, headache, dizziness, and nausea. These are types of effects that can influence a person's general feeling day-to-day.


Q: What happens if I take Hepai for longer than expected?

As treatment is typically long-term, regulatory requirements mandate periodic monitoring of liver enzymes and blood cell counts. This monitoring is intended to manage the risks associated with the continuous, long-term nature of the medicine's use.


Q: Is there a generic version of Hepai available?

Official public assessment reports confirm that generic versions of the active substance, Leflunomide, are available in regulated regions like the European Union.


Q: Does alcohol change the effect of Hepai?

Regulatory information warns that due to the potential for both the medicine and alcohol to affect the liver, combining them can significantly increase the risk of severe liver damage. Healthcare providers generally counsel patients to avoid alcohol during treatment.


Q: Why is the official dosage range so broad for Hepai?

Official product information indicates that the recommended maintenance dose range is not fixed, but is determined by the specialist based on the patient's condition. This variability is officially described as being based on the specialist's assessment of the activity and severity of the patient's specific disease.


Q: Is Hepai considered a high-risk medication?

The medicine is classified as an Immunosuppressive Disease-Modifying Antirheumatic Drug (DMARD). It carries a Boxed Warning in the US for serious potential risks, including liver failure and fetal risk. This designation indicates the importance of careful monitoring during use, as described in official labeling.


Q: Can Hepai be split or crushed?

Official documentation is mixed: while some resources state the tablet can be divided into equal doses, the explicit instruction also provided is for the tablets to be swallowed whole with liquid.


Q: Is it possible to develop a tolerance to Hepai?

Clinical studies track patients who discontinued the medicine due to a reported loss of effect over time. This indicates that a reduced therapeutic response can occur with prolonged use.


Q: Can I take cold and flu medication while using Hepai?

Regulatory warnings advise against the concurrent use of any over-the-counter medicine containing Acetaminophen (Paracetamol). This is to prevent accidental overdose or increased risk of liver toxicity.


Q: Is it true that Hepai is associated with [minor, non-serious side effect]?

The official safety profile lists several commonly reported reactions, such as diarrhea, rash, nausea, and hair loss (alopecia). These effects are classified by frequency in the regulatory documents.

How should Hepai be stored and disposed of?

The storage and disposal of Hepai (Leflunomide) must adhere strictly to regulatory requirements to ensure product quality and safety.

Official Storage Conditions

Hepai tablets must be stored at room temperature, away from any source of excess heat and moisture. The medicine must be kept from freezing and should be placed away from direct light.

To ensure stability, the container or blister packaging must be kept tightly closed and in its original package.

Disposal and Child Safety

All medication, including Hepai, must be stored out of the sight and reach of children in a safe, secure location.

Disposal of unused or expired product must be done in accordance with local regulations. The preferred method is to return the medicine to an authorized drug take-back program. If a take-back program is unavailable, follow the official procedure for household disposal, which includes mixing the medicine with an undesirable substance in a sealed container.

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

Available in countries:

Equivalent of Hepai found in:

A-Z Index: