Key takeaways

  • Promacta (eltrombopag) can cause side effects ranging from mild issues like nausea and fatigue to more serious complications, such as cataracts.
  • Promacta has boxed warnings about the potential for liver damage and increased risk of liver problems, especially in people with chronic hepatitis C. This requires regular liver function monitoring by your doctor.
  • While some side effects, like hair loss, are more common, others, like blood clots, are rare. If you’re concerned about side effects, tell your doctor, as they can adjust your treatment plan as needed.

Promacta is used in adults and certain children to treat the following conditions in specific situations:

Keep reading to learn about the common, mild, and serious side effects Promacta can cause.

Promacta has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section.

Some people may experience mild to serious side effects during their Promacta treatment. Examples of this drug’s commonly reported side effects include:

  • cough
  • fever
  • headache
  • nausea
  • anemia (low level of red blood cells)

Keep reading to learn about other possible mild and serious side effects of Promacta.

Promacta may cause mild side effects for some people. Examples that have been reported with this drug include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop taking Promacta unless your doctor recommends it.

Promacta may cause mild side effects other than those listed above. See the drug’s prescribing information for details. To learn more about some of these side effects, see the “Side effects explained” section.

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Although uncommon, serious side effects can happen with Promacta. Serious side effects that have been reported with this drug include:

If you develop serious side effects while taking Promacta, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Promacta and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

To learn more about some of these side effects, see the “Side effects explained” section.

Get answers to some frequently asked questions about Promacta’s side effects.

What are Promacta’s long-term side effects?

Promacta may cause long-term side effects, such as:

  • liver damage or liver problems in people with chronic hepatitis C
  • increased risk of blood clots, which can cause serious problems such as heart attack or stroke
  • cataracts, which can lead to vision loss

These side effects may start during treatment and continue for a long time, even possibly after treatment ends. So if you do experience them, your doctor may stop Promacta treatment to help lower the risk of long-term complications.

If you have concerns about the long-term side effects of Promacta, talk with your doctor. To learn more about some of these side effects, see the “Side effects explained” section.

Is Promacta safe for older adults?

Yes, Promacta is considered safe for older adults. In studies, people ages 65 years and older generally had the same side effects as younger adults. To learn more about Promacta and possible age-related side effects, talk with your doctor or pharmacist.

Does Promacta cause weight gain?

No, it’s not likely. Weight gain wasn’t reported as a side effect in studies of Promacta. But other treatments for blood disorders may cause this side effect. For example, corticosteroids are known to cause weight gain. Examples include Hemady (dexamethasone) and Rayos (prednisone).

If you’re concerned about weight gain with Promacta or other treatments you may be receiving, talk with your doctor. They can advise you on your risk of this side effect and suggest ways to manage it.

Learn more about some of the side effects Promacta may cause.

Risk of liver damage

Promacta has a boxed warning for the risk of liver damage. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). Liver damage was a rare side effect in studies of Promacta. But in extreme cases, this side effect can be life threatening.

Symptoms of liver damage can include:

What might help

Before starting Promacta, your doctor will order liver function tests to check how well your liver is working. They’ll repeat these tests from time to time during your treatment. If you have a liver problem before starting this drug, your doctor will determine whether it’s the right treatment option for you.

If you have symptoms of liver damage while taking Promacta, tell your doctor right away. They can determine whether it’s safe for you to keep taking the drug. If you do continue taking Promacta but your liver damage worsens or returns, your doctor may change your treatment.

Risk of liver problems in people with chronic hepatitis C

Promacta has a boxed warning for the risk of liver problems in people with chronic (long-term) hepatitis C. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

If you have chronic hepatitis C, taking Promacta with certain hepatitis C treatments may increase your risk of decompensated liver disease. This was a less common side effect in Promacta studies. With this condition, your liver doesn’t work as well as it should. This can lead to ascites (fluid buildup in your abdomen) and encephalopathy (a severe brain condition).

Other symptoms of liver problems include:

  • jaundice
  • dark urine
  • right upper abdominal pain
  • fatigue

What might help

Tell your doctor right away if you have symptoms of liver problems while taking Promacta. If you’re found to have liver problems, they’ll likely stop your Promacta and hepatitis C treatments. They’ll discuss any treatments that are needed for your liver problems.

Cataracts

Cataracts were a less common side effect in studies of Promacta. Cataracts are cloudy areas in the lens of your eye. Symptoms may include:

What might help

If you have symptoms of cataracts while taking Promacta, talk with your doctor. They may suggest seeing an eye doctor to check and treat your symptoms. If you have cataracts before starting Promacta or develop them during treatment, your doctor will determine whether it’s safe for you to take this medication.

Hair loss

Hair loss was one of the more common side effects in studies of Promacta. Symptoms can include:

What might help

While taking Promacta, treating your hair gently may help lessen hair loss. This includes avoiding styling tools, such as curling irons and straighteners, and hair treatments, such as hair color or perms.

You can also talk with your doctor for tips on how to manage this side effect.

Allergic reaction

Like most drugs, Promacta can cause an allergic reaction in some people, but this side effect wasn’t reported in studies.

Symptoms of an allergic reaction can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

If your doctor confirms you’ve had a mild allergic reaction to Promacta, they’ll determine whether you should continue taking it.

Call 911 or your local emergency number right away if you have symptoms of a severe allergic reaction, such as swelling or trouble breathing. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Promacta, they may have you switch to a different treatment.

Consider the following important information before starting Promacta

Boxed warnings

Promacta has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section.

Other precautions

Before taking Promacta, discuss your health history with your doctor. Promacta may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.