Pronunciation: pro-MAC-ta
Generic name: eltrombopag
Dosage form: tablet (12.5 mg, 25 mg, 50 mg, 75 mg), for oral suspension (12.5 mg, 25 mg)
Drug class: Platelet-stimulating agents

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 17, 2025.

What is Promacta?

Promacta is a man-made form of a protein that stimulates cells in the bone marrow to produce more platelets (blood-clotting cells). Eltrombopag belongs to a class of medications called thrombopoietin receptor agonists.

Promacta is used to increase the number of platelets (cells that help the blood clot) to decrease the risk of bleeding in adults and children one year of age and older who have chronic immune thrombocytopenia (ITP; an ongoing condition that may cause unusual bruising or bleeding due to an abnormally low number of platelets in the blood) and who have not been helped or cannot be treated with other treatments, including medications or surgery to remove the spleen.

Promacta is also used to increase the number of platelets in people who have hepatitis C (a viral infection that may damage the liver) so that they can begin and continue treatment with interferon (Peginterferon, Pegintron, others) and ribavirin (Rebetol).

Promacta is also used in combination with other medications to treat aplastic anemia (a condition in which the body does not make enough new blood cells) in adults and children 2 years of age and older.

Promacta is also used to treat aplastic anemia in adults who have not been helped with other medications. Promacta is used to increase the number of platelets enough to decrease the risk of bleeding in people with ITP or aplastic anemia, or to allow treatment with interferon and ribavirin in people with hepatitis C. However, it is not used to increase the number of platelets to a normal level.

Promacta should not be used to treat people who have low numbers of platelets due to conditions other than ITP, hepatitis C, or aplastic anemia.

Promacta is not for use in treating myelodysplastic syndrome (also called "preleukemia").

Warnings

Before you take Promacta, tell your doctor if you have kidney disease, blood cancer, a bone marrow disorder, high platelet levels, liver problems (if you are not being treated for hepatitis C), a history of cataracts or blood clots, if your spleen has been removed, or if you are of East Asian descent. Also, tell your doctor about all other medications you use.

BOXED WARNING: Promacta with interferon/ribavirin in chronic hepatitis C patients increases the risk of potentially fatal liver damage (hepatic decompensation). Regular liver function monitoring is required. Discontinue if liver problems develop. Call your doctor at once if you have signs of liver problems: nausea, upper stomach pain, confusion, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Take Promacta on an empty stomach, at least 1 hour before or 2 hours after a meal. Do not take this medication with milk. Avoid all dairy products or products that contain calcium (including fortified fruit juice) for at least 4 hours before or after you take Promacta.

After you stop taking this medicine, your risk of bleeding may be even higher than it was before you started treatment. Be extra careful to avoid cuts or injury for at least 4 weeks after you stop taking this medicine. Your blood will need to be tested weekly during this time.

Before taking this medicine

To make sure Promacta is safe for you, tell your doctor if you have ever had:

• a blood clot;

• blood cancer or a bone marrow disorder:

• myelodysplastic syndrome (MDS);

• bleeding problems;

• cataracts;

• surgery to remove your spleen;

• kidney disease;

• if you are of East or Southeast Asian descent, or

• liver disease (unless you are being treated for hepatitis C).

May harm an unborn baby. Do not use if you are pregnant. Use effective birth control while using Promacta and for at least 7 days after your last dose. Tell your doctor if you become pregnant.

You should not breastfeed while using this medicine.

How should I take Promacta?

Take Promacta exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

You may take Promacta in any of the following ways:

• on an empty stomach, at least 1 hour before or 2 hours after eating;

• with a meal containing fewer than 50 milligrams of calcium; or

• at least 2 hours before or 4 hours after eating foods high in calcium (dairy products, calcium-fortified juices, certain fruits and vegetables).

Swallow the tablet whole and do not crush, chew, break it or mix with food or liquid.

Mix the oral suspension powder only with cool or cold water. Use a new dosing syringe each time you mix the medicine to measure the water and to give the correct dose.

You may need frequent medical tests to check your bone marrow cells or liver function. Your eyes may also need to be checked for signs of cataracts.

Promacta is usually taken for 6 months. It may take up to 4 weeks before the medicine prevents major bleeding episodes.

Keep taking Promacta as directed. Tell your doctor if you have any bruising or bleeding that happens while you take and after you stop taking Promacta.

If you take Promacta with medication to treat chronic hepatitis C, tell your doctor if you stop using any of your hepatitis medications.

Store at room temperature away from moisture and heat. Keep the tablets in their original container. After mixing Promacta oral suspension, use it right away; if it is not used within 30 minutes, throw it away in the trash only.

After you stop taking Promacta, your risk of bleeding or bruising may be even higher than it was before you started treatment. Your blood will need to be tested weekly during this time.

Eltrombopag doses are based on weight in children younger than 6 years old. Your child's dose needs may change if the child gains or loses weight.

Dosing Information

Adults

Severe Aplastic Anemia (First-Line)

• Standard: 150 mg once daily
• Asian ancestry: 75 mg once daily
• Duration: 6 months

Severe Aplastic Anemia (Refractory)

• Standard: Start 50 mg once daily
• Asian ancestry: Start 25 mg once daily
• Adjust by 50 mg every 2 weeks to maintain platelets 50-200 × 10⁹/L
• Maximum: 150 mg once daily
• Discontinue if no response after 16 weeks

Immune Thrombocytopenic Purpura (ITP)

• Standard: Start 50 mg once daily
• East Asian ancestry: Start 25 mg once daily
• Titrate to maintain platelets 50-200 × 10⁹/L
• Maximum: 75 mg once daily
• Discontinue if inadequate response after 4 weeks at maximum dose

Thrombocytopenia (with Hepatitis C treatment)

• Start: 25 mg once daily
• Maximum: 100 mg once daily
• Discontinue when antiviral therapy stops

Pediatrics

Immune Thrombocytopenic Purpura (ITP)

• Ages 1-5 years: Start 25 mg once daily
• Ages 6+ years: Start 50 mg once daily
• East Asian ancestry (all ages): Start 25 mg once daily
• Titrate to maintain platelets 50-200 × 10⁹/L
• Maximum: 75 mg once daily
• Discontinue if inadequate response after 4 weeks at maximum dose

Severe Aplastic Anemia (First-Line)

Standard Dosing:

• Ages 2-5 years: 2.5 mg/kg once daily
• Ages 6-11 years: 75 mg once daily
• Ages 12+ years: 150 mg once daily

Asian Ancestry:

• Ages 2-5 years: 1.25 mg/kg once daily
• Ages 6-11 years: 37.5 mg once daily
• Ages 12+ years: 75 mg once daily

Duration: 6 months

Note: All doses are oral, once daily. Adjust to the lowest effective dose, maintaining target platelet counts.

What happens if I miss a dose?

Skip the missed dose and take your next dose at the regular time. Do not take two doses in one day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Taking too much eltrombopag may cause a life-threatening blood clot.

What should I avoid while taking Promacta?

Ask your doctor before using an antacid, and use only the type your doctor recommends. Some antacids can make it harder for your body to absorb eltrombopag and should not be taken at the same time.

Avoid activities that may increase your risk of bleeding or injury for at least 4 weeks after you stop taking Promacta. Use extra care while shaving or brushing your teeth.

Promacta side effects

Most Common Side Effects

• Low red blood cell counts (anemia)
• Nausea
• Fever
• Abnormal liver function tests
• Cough
• Tiredness
• Headache
• Diarrhea

Laboratory tests may show abnormal changes to the cells in your bone marrow

Serious Side Effects 

Liver Problems:

Promacta may increase your risk of liver problems that may be severe and possibly life-threatening. Your healthcare provider will do blood tests to check your liver function before you start taking Promacta and during your treatment. Your healthcare provider may stop your treatment with Promacta if you have changes in your liver function blood tests. Tell your healthcare provider right away if you have any of these signs and symptoms of liver problems:

• Yellowing of the skin or the whites of the eyes (jaundice)
• Unusual darkening of the urine
• Unusual tiredness
• Right upper stomach area (abdomen) pain
• Confusion
• Swelling of the stomach area (abdomen).

Worsening of a Precancerous Blood Condition:

There is an increased risk of worsening of a precancerous blood condition called myelodysplastic syndrome (MDS) to acute myelogenous leukemia (AML) in patients taking Promacta. Promacta is not for use in people with MDS.

High Platelet Counts and a Higher Risk for Blood Clots:

Your risk of getting a blood clot is increased if your platelet count is too high during treatment with Promacta. Your risk of getting a blood clot may also be increased during treatment with Promacta if you have normal or low platelet counts. You may have severe problems or die from some forms of blood clots, such as clots that travel to the lungs or that cause heart attacks or strokes. Your healthcare provider will check your blood platelet counts and change your dose or stop Promacta if your platelet counts get too high. 

Call your doctor or get emergency medical help if you have:

• signs of a stroke - sudden numbness or weakness, severe headache, slurred speech, problems with vision or balance;

• signs of a blood clot in the lung - chest pain, sudden cough or shortness of breath, dizziness, coughing up blood;

• signs of a blood clot deep in the body - pain, swelling, or warmth in one leg; or

• signs of a blood clot in the stomach - severe stomach pain, vomiting, diarrhea.

People with chronic liver disease may be at risk for a type of blood clot in the stomach area (abdomen). Tell your healthcare provider right away if you have stomach-area (abdomen) pain, nausea, vomiting, or diarrhea, as these may be symptoms of this type of blood clot.

New or worsened cataracts (a clouding of the lens in the eye):

New or worsened cataracts can happen in people taking Promacta. Your healthcare provider will check your eyes before and during your treatment with Promacta. Tell your healthcare provider about any changes in your eyesight.

Allergic Reactions

Get emergency medical help if you have signs of an allergic reaction to Promacta: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

What other drugs will affect Promacta?

Some medicines can make Promacta much less effective when taken at the same time. If you take any of the following medicines, take your Promacta dose 2 hours before or 4 hours after you take the other medicine:

• antacids that contain calcium, magnesium, or aluminum; or

• vitamin or mineral supplements that contain aluminum, calcium, iron, magnesium, selenium, or zinc.

Tell your doctor about all your other medicines, especially:

• medicine used to prevent blood clots - alteplase, clopidogrel, dipyridamole, warfarin, enoxaparin, apixaban, ticlopidine, and others; or

• cholesterol-lowering medicine - atorvastatin, ezetimibe, fluvastatin, pitavastatin, pravastatin, rosuvastatin, or simvastatin.

Promacta's color can interfere with laboratory tests, including bilirubin, creatinine, protein, and albumin, causing inaccurate results. Inform laboratories that you take Promacta.

This list is not complete. Other drugs may interact with eltrombopag, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Ingredients

Active ingredient: eltrombopag olamine
Inactive ingredients: Tablet Core: magnesium stearate, mannitol, microcrystalline cellulose, povidone, and sodium starch glycolate.
Coating: FD& C Blue No. 2 aluminum lake (50-mg tablet), FD& C Yellow No. 6 aluminum lake (25-mg tablet), hypromellose, Iron Oxide Black and Iron Oxide Red (75-mg tablet), polyethylene glycol 400, polysorbate 80 (12.5-mg tablet), or titanium dioxide.

Manuacturer

Distributed by: Novartis Pharmaceuticals Corporation, East Hanover, New Jersey 07936.

Popular FAQ

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer