Promacta

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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 Promacta

Quick Facts

Property Description
Active ingredient Eltrombopag (as Eltrombopag Olamine salt)
Form Tablets; Powder for oral suspension
Pharmacological class Thrombopoietin Receptor Agonist (TPO-RA)
Common purpose To increase platelet counts to mitigate bleeding risk
Origin Synthetic, non-peptide small molecule

Promacta is the brand name for the oral prescription medicine that contains the active ingredient Eltrombopag. The compound is a synthetic, non-peptide small molecule, which means it is chemically manufactured and is not a protein. It belongs to the pharmacological class known as a Thrombopoietin Receptor Agonist (TPO-RA). A distinguishing feature of Promacta is its availability in two distinct dosage forms for oral administration: film-coated tablets and a powder for oral suspension. This dual formulation ensures flexibility for administration across different patient groups.

What Type of Medicine is Eltrombopag?

Eltrombopag is fundamentally a highly targeted hematologic agent clinically recognized for its ability to address platelet deficiencies. Its mechanism involves binding to the TPO receptor in the bone marrow, triggering a selective signaling cascade that stimulates the proliferation and differentiation of megakaryocytes. This mechanism is key because it provides a dedicated, focused method for addressing the production deficiency at its source.

The general purpose of the medicine is to counteract the effects of thrombocytopenia, a condition characterized by abnormally low platelet counts. By stimulating the bone marrow to produce these essential clotting cells, Eltrombopag helps to elevate the platelet count, thereby reducing the patient's elevated risk of bleeding events.

Regulatory References

  1. Eltrombopag: Thrombopoietin Receptor Agonists
  2. Eltrombopag: MedlinePlus Drug Information

What side effects are possible with Promacta?

Possible Side Effects and Safety Information

The official safety profile for Eltrombopag (Promacta) is defined by a range of documented adverse reactions and strict monitoring requirements, as established by regulatory authorities. The adverse events are categorized by frequency and the body's organ systems involved.

Frequency-Classified Adverse Reactions

Adverse reactions are classified based on the frequency observed in clinical studies. Very Common or Most Common events, occurring in ge 1/10 patients, include nausea, diarrhea, upper respiratory tract infection, and increases in liver transaminases, specifically Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST). Common reactions, occurring in ge 1/100 to < 1/10 patients, include headache, fatigue, cough, and rash.

Serious Safety Considerations

The most serious safety concerns documented in regulatory labeling relate to the liver and the vascular system. The medicine is associated with a risk of Severe Hepatotoxicity (liver damage). Additionally, there is a documented risk of Thrombotic and Thromboembolic Complications (blood clots), which is heightened when platelet counts become excessively high. For patients with Chronic Hepatitis C (HCV) and cirrhosis, there is an explicit warning regarding the risk of Hepatic Decompensation.

Population and Safety Limitations

Specific safety considerations exist for certain patient groups. Individuals with hepatic impairment or of East-/Southeast-Asian ancestry require a lower initial starting dose due to increased systemic exposure. The label also sets a critical safety restriction: the goal of treatment is not to normalize platelet counts, but to reach a level that reduces bleeding risk, specifically advising that platelet counts exceeding 200 imes 10^9/ L may increase the risk of thrombotic events.

Overdose and Emergency Response

Overdose and When to Seek Help

Overexposure to Promacta (Eltrombopag) is officially documented by regulatory authorities to lead primarily to an excessive increase in platelet counts. This physiological response poses a severe risk of thrombotic or thromboembolic complications, which are classified as potentially life-threatening outcomes. In observed cases of overexposure, reported manifestations have also included systemic signs such as bradycardia (slowed heartbeat), fatigue, rash, and laboratory findings like elevated serum liver tests (transaminases).

Management is focused on symptomatic and supportive treatment due to the absence of a specific known antidote. Official protocols mandate frequent monitoring of platelet counts to mitigate the risk of severe thrombotic events, along with required monitoring of liver function to assess potential hepatotoxicity.

Immediate medical attention must be sought if an overdose is suspected. Regulatory guidance states that emergency services must be called immediately if the person has collapsed, had a seizure, is experiencing trouble breathing, or cannot be awakened. Furthermore, patients with hepatic impairment are noted to have a higher risk of overexposure due to their reduced ability to clear Eltrombopag, which impacts initial dose considerations.

Therapeutic Uses of Promacta

Promacta (Eltrombopag) is commonly used in clinical settings that involve acute or unstable symptom patterns where low platelet counts (thrombocytopenia) create noticeable physiological strain or interfere with necessary medical intervention. The medication plays a role in managing symptoms and supports functional stability by helping to increase the number of platelets. The medication is applied across specific therapeutic domains.

The medication is commonly used across conditions presenting with significant symptomatic burden, including Chronic Immune Thrombocytopenia (ITP), support for Severe Aplastic Anemia (SAA), and the treatment of thrombocytopenia associated with Chronic Hepatitis C (HCV) infection.

This treatment helps address hemorrhagic manifestations—symptoms like frequent bruising, petechiae, and excessive surface bleeding. It is often applied during phases when symptoms become more noticeable, offering supportive relief when low platelet counts affect the ability to receive necessary care.

“The medication supports patients during difficult episodes by easing distress and contributes to easing the overall symptom load by assisting with the management of bleeding risk.”


Quick Fact: Relief for Hemorrhagic Manifestations

Therapeutic Focus Benefit to Patient
Symptom Category Symptoms related to systemic imbalance
Clinical Context Applied in clinical settings that involve acute or unstable symptom patterns
Core Benefit Contributes to improved comfort by minimizing the frequency of surface bleeding

Eligibility and Restrictions for Use

Promacta (eltrombopag) is authorized for specific conditions and patient groups, as defined by official regulatory bodies like the FDA and EMA.

Populations for Use

Eligibility generally requires a diagnosis of Chronic Immune Thrombocytopenia (ITP) in patients 1 year of age, Severe Aplastic Anemia (SAA) in patients 2 years of age (first-line in combination therapy), or Chronic Hepatitis C (HCV)-associated thrombocytopenia in adults (to facilitate interferon-based therapy). Use is explicitly limited to patients whose low platelet count increases their risk for bleeding; it must not be used to attempt to normalize platelet counts.

Use Restrictions and Exclusions

Classification Population or Condition
Contraindicated Patients with known hypersensitivity to eltrombopag or any excipients.
Not Indicated Patients with Myelodysplastic Syndromes (MDS), due to increased risk of death and progression to Acute Myeloid Leukemia (AML).
Special Consideration Patients with hepatic impairment (Child-Pugh Class A, B, or C) or of East/Southeast Asian ancestry require a lower starting dose.
Pregnancy/Lactation Use in pregnancy is permitted only if the potential benefit justifies the risk to the fetus. It is unknown if the drug passes into breast milk; a decision must be made to discontinue nursing or the medicine.

Safety and efficacy have not been established in pediatric patients under 1 year old (ITP) or in combination with non-interferon Direct-Acting Antiviral (DAA) agents for HCV.

What should I know about interactions with other medicines?

Promacta (Eltrombopag) has documented interaction patterns that are primarily pharmacokinetic. The most critical constraint involves polyvalent cations found in certain medicines, supplements, and foods, such as dairy products, antacids, and mineral supplements containing iron, calcium, or magnesium. These cations can significantly reduce the absorption of Eltrombopag. To manage this interaction, the regulatory label specifies a mandatory timing rule: Promacta must be administered at least 2 hours before or 4 hours after any products containing these cations.

Eltrombopag also functions as an inhibitor of several drug transporters and metabolic enzymes. Specifically, it inhibits the transporters OATP1B1 and BCRP, as well as UGT1A1 and UGT1A6 enzymes. This inhibition can officially increase the plasma exposure of co-administered medicines that are substrates for these systems, including drugs such as Rosuvastatin and Acetaminophen.

The official interaction profile includes a specific combination risk: when used alongside interferon and ribavirin for Chronic Hepatitis C, there is an increased risk of hepatic decompensation. Furthermore, certain populations have documented differences in drug clearance, leading to higher systemic exposure. A reduced starting dose is a requirement for patients with moderate or severe hepatic impairment and those of East/Southeast Asian ancestry.

Mechanism of Action

How Promacta Works

Eltrombopag initiates its mechanism by acting as a highly selective agonist of the Thrombopoietin Receptor (TPO-R), a protein found on the surface of megakaryocyte progenitor cells in the bone marrow. The drug employs non-competitive binding, engaging the TPO-R's transmembrane domain, a site distinct from where the body's natural ligand, Thrombopoietin, binds. This molecular engagement triggers the receptor to send an activation signal.

Once activated, the TPO-R initiates the crucial JAK/STAT signaling cascade within the progenitor cell. This intracellular process accelerates the necessary gene expression and cellular processes for megakaryopoiesis (the creation and maturation of platelet-forming cells). The functional consequence of this sustained molecular signaling is an increase in the proliferation and differentiation of megakaryocytes, which leads directly to an increase in the number of functional platelets released into the bloodstream. A chemical constraint on the mechanism is the drug's ability to act as a chelator of polyvalent cations (such as calcium and iron) in the digestive tract, which prevents absorption and blocks the drug from reaching its TPO-R target.

Dosage and Administration Information

Administration and Dosing Instructions

Promacta (eltrombopag) is administered orally and must be taken once daily. The medicine is available as a tablet and as a powder for oral suspension. All patients are started on a specific initial daily dose, which is lower for those of East/Southeast-Asian ancestry or those with certain degrees of hepatic impairment.


Timing and Preparation Rules

To ensure proper absorption, the medicine must be taken with respect to meals and other products.

  • Food Timing: Take Promacta without a meal (i.e., at least 1 hour before or 2 hours after a meal) or with a meal low in calcium (less than or equal to 50 mg of calcium).
  • Cation Separation: A time interval of at least 4 hours must be allowed between taking Promacta and consuming any medications, supplements, or foods (including dairy and calcium-fortified juices) that contain polyvalent cations (e.g., calcium, iron, aluminum, magnesium, selenium, and zinc).
  • Tablet Form: Tablets must be swallowed whole and should not be crushed, broken, or chewed.
  • Oral Suspension Form: The powder must be mixed with cool or cold water only and taken immediately after preparation, or discarded if not taken within 30 minutes.

Dose Adjustment and Monitoring

Official instructions require the dose to be actively managed based on laboratory results. After starting, platelet counts are monitored regularly (e.g., weekly initially, then monthly) until a stable dose is reached. The daily dose is adjusted in specific increments, usually 25 mg, to maintain the platelet count within a target range. The dosage should not exceed a set maximum daily dose (e.g., 75 mg for most adults with Chronic Immune Thrombocytopenia). If a dose is missed, the patient should skip that dose and continue with the regular once-daily schedule, as double doses are not permitted.

Recent Clinical Evidence

Promacta: Recent Clinical Evidence

Promacta (eltrombopag) is a thrombopoietin receptor agonist indicated for the treatment of thrombocytopenia (low platelet counts) in several conditions. Research has primarily focused on its use in chronic Immune Thrombocytopenia (ITP) and Severe Aplastic Anemia (SAA).


Chronic Immune Thrombocytopenia (ITP)

Controlled clinical trials in adults with previously treated chronic ITP have demonstrated that the drug may be associated with statistically significant increases in platelet counts compared to placebo. A key goal of treatment in these trials was to achieve and maintain a platelet count of 50 imes 10^9/L or higher, which is generally considered a level that helps manage the risk of bleeding.

The long-term, open-label EXTEND study evaluated the drug's safety and effectiveness over several years. Results from this study indicated that a majority of participants achieved and maintained the target platelet count. The study also reported that the incidence of bleeding symptoms often decreased over time, and some patients were able to reduce or discontinue the use of concomitant ITP medications while maintaining a platelet response.


Severe Aplastic Anemia (SAA)

Promacta is also indicated for patients with SAA, including first-line treatment in combination with standard immunosuppressive therapy. Clinical findings in SAA patients who had an insufficient response to prior immunosuppressive therapy suggested that the drug may be associated with multilineage hematologic response, including improvements in platelet, red cell, and white cell counts.

Monitoring of liver enzymes and platelet counts is an integral component of the treatment protocol across all indications, as trial data have highlighted the potential for increases in liver enzymes and the risk of thrombotic events if platelet counts become excessively elevated.

Frequently Asked Questions (FAQ)

Common questions about Promacta (FAQ)

Q: What happens if I stop taking Promacta suddenly?

Regulatory documents indicate that platelet counts generally return to the level they were before treatment within one to two weeks after stopping the medication. This decrease can lead to worsened thrombocytopenia (low platelet count) and an increased risk of bleeding. Platelet counts are monitored for at least four weeks after discontinuation, according to official guidance.

Q: How long might I need to take Promacta?

The duration of treatment is determined by the prescribing physician based on the patient's specific condition and how the platelet count responds. According to clinical studies, including long-term research, the medication has been evaluated and used for extended periods, sometimes for up to several years, in people with chronic Immune Thrombocytopenia (ITP). The goal is to achieve and maintain a stable, non-bleeding platelet count.

Q: Is Promacta safe to take during pregnancy?

Official information states that there is currently insufficient data available to fully assess the drug's risks regarding birth defects, miscarriage, or other adverse outcomes in humans. Therefore, it is permitted to be used during pregnancy only if the potential benefits clearly justify the potential risks to the fetus. This assessment is a required discussion point with a healthcare provider.

Q: What is the difference between Promacta and other TPO-receptor agonists?

Promacta (eltrombopag) is an oral, non-peptide type of thrombopoietin receptor agonist (TPO-RA). This means it is a chemically manufactured small molecule, rather than a protein. It is noted for binding to a unique location (transmembrane domain) on the TPO-receptor in the bone marrow, which is different from where the body's natural signaling protein binds. Other TPO-RAs may be peptide-based or bind to the receptor in a different way.

Q: Is Promacta a blood thinner?

No, Promacta is not a blood thinner. The medication is classified as a Thrombopoietin Receptor Agonist (TPO-RA). Its mechanism is to actively stimulate the bone marrow to produce more platelets, which are the cells responsible for clotting. This action is the opposite of a blood thinner (anticoagulant), which would reduce the body's ability to form clots.

Q: Why is Promacta only prescribed by specialist doctors?

In some regions, the medicine was managed under a Risk Evaluation and Mitigation Strategy (REMS) program. This type of program is put in place by regulatory bodies to help manage known serious risks, such as liver toxicity and the potential for blood clots. Such programs often involve restricted distribution and may require prescribers to have specific qualifications to ensure the medication is used safely.

Q: Can Promacta be taken alongside blood transfusions?

Official product information discusses the use of this medication in treating conditions like Severe Aplastic Anemia, where patients often receive blood transfusions. The medication's purpose is to help increase the platelet count to reduce the need for transfusions. The label indicates the drug is used in contexts where transfusions may occur, but does not specify a direct interaction.

Q: What if I take Promacta and feel no change in my platelet count?

Official regulatory guidance states that if the platelet count does not increase to a level sufficient to avoid clinically important bleeding after four weeks at the maximum allowed dose, the medication should be discontinued. Because dosage adjustments are managed closely, the prescribing doctor will regularly monitor platelet count and adjust the dose to ensure an appropriate response is achieved.

Q: Can Promacta cause or worsen cataracts?

Official safety information for Promacta notes that the medication is associated with a risk of developing cataracts, and it may also worsen cataracts that are already present. This is a documented side effect observed in clinical studies.

Q: Why is it important to have regular eye exams while taking Promacta?

Due to the documented risk of cataracts associated with the medication, regulatory guidelines state that patients are monitored for eye changes. An eye examination is typically performed before starting treatment, and patients are routinely monitored for any signs or symptoms of cataracts throughout the course of therapy.

Q: What distinguishes Promacta's use in chronic hepatitis C from its use in ITP?

The purpose of the medication differs between the two conditions. In Chronic Hepatitis C, the treatment goal is specifically to raise platelet counts high enough to allow patients to initiate and maintain standard interferon-based therapy. For Chronic ITP, the goal is simply to increase the platelet count to a level that reduces the patient's overall risk of bleeding.

Q: Does the time of day matter when taking Promacta?

Official dosing instructions specify that the medication must be taken once daily, and they impose strict rules regarding its relationship to meals and supplements containing polyvalent cations (such as iron or calcium). However, the label does not specify a required time of day for administration.

Q: Is it possible to become resistant to the effects of Promacta over time?

Long-term clinical studies, such as the EXTEND trial, have monitored patients for several years. This evidence suggests that many patients are able to sustain a long-term response and maintain platelet counts in the desired range over time.

Q: How does Promacta's mechanism contrast with corticosteroid treatments for ITP?

Promacta and corticosteroids work through entirely different mechanisms. Promacta is a TPO-R agonist that acts directly on the bone marrow to stimulate the production of new platelets. Corticosteroid treatments, by contrast, work by acting on the immune system to suppress the destruction of platelets that are already circulating in the blood.

Q: What happens when treatment with Promacta is successfully stopped?

When a successful course of treatment is completed and the medication is stopped, platelet counts are expected to return to their baseline levels within approximately one to two weeks. Because there is a risk of severe thrombocytopenia (worsened low platelets) after stopping, close monitoring for at least four weeks is noted in official guidance.

Q: How quickly does Promacta start to affect platelet numbers?

Clinical trial data indicate that in most patients, platelet counts typically begin to increase within one to two weeks after the start of therapy. Regular monitoring and dose adjustments are part of the standard treatment protocol to achieve an optimal platelet count.

How should Promacta be stored and disposed of?

How to Store and Dispose of Promacta (Eltrombopag)

Promacta must be stored at controlled room temperature, specifically between 20 C and 25 C (68 F and 77 F), while protecting it from excess heat and moisture. The tablets must be kept in the original container, tightly closed, and any desiccant packet must remain inside. Tablets should not be crushed, split, or chewed.

The powder for oral suspension has a strict post-preparation limit: once mixed, it must be swallowed immediately or discarded within 30 minutes. Unused liquid mixture should be thrown away in the trash and must not be poured down the sink or flushed. Promacta, like all medicines, must always be kept out of the reach of children.

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

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