Nplate (romiplostim) is a prescription drug that’s used to treat a low level of blood platelets. Nplate can cause side effects that range from mild to serious. Examples include joint pain and dizziness.

Nplate is used in adults and certain children to:

The active ingredient in Nplate is romiplostim. (An active ingredient is what makes a drug work.) Nplate is a biologic drug, which means it’s made from living cells.

Nplate comes as a powder that’s mixed into a liquid solution. A healthcare professional will administer it as an injection under the skin.

Keep reading to learn about the common, mild, and serious side effects that Nplate can cause. For a general overview of the drug, including details about its uses, see this article.

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

* To learn more about this side effect, see the “Side effects explained” section below.

Mild side effects have been reported with Nplate. These 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 Nplate treatment unless your doctor recommends it.

Nplate may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.

Serious side effects have been reported with Nplate. These include:

If you develop serious side effects during Nplate treatment, 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.

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Nplate, visit MedWatch.

Nplate may cause some different side effects in children. The drug is used in children ages 1 year and older to treat immune thrombocytopenia that doesn’t respond to other medications. It’s also used to increase survival in children who’ve been exposed to radiation that’s affected their bone marrow.

Some common side effects in children include:

Below are answers to some frequently asked questions about Nplate’s side effects.

Can Nplate cause long-term side effects?

While most side effects of Nplate are temporary, a few long-term side effects were reported by people using the drug in studies. Long-term side effects refer to those which may last a long time or those which may start or continue after treatment ends. Possible long-term side effects of Nplate include:

Your doctor will monitor your blood levels during your Nplate treatment. If they notice blood clots or any problems with your bone marrow, they’ll determine whether it’s safe for you to continue treatment.

If you have questions about long-term side effects of this drug, ask your doctor for more information.

If I stop using Nplate, will I experience certain side effects?

This isn’t likely. Because Nplate is used to increase the level of platelets in your blood, your platelet level may drop when you stop taking the drug. This could increase your risk of bleeding.

Your doctor will monitor your blood levels and suggest a different treatment to manage your condition, if necessary. Talk with them if you have concerns about possible side effects that may occur from stopping Nplate.

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


Insomnia (trouble sleeping) was commonly reported by people using Nplate in studies. This is usually a mild side effect that goes away after a few days to weeks.

What might help

If you experience bothersome or ongoing insomnia with Nplate treatment, talk with your doctor. They can suggest ways to help manage this side effect. This may include tips such as:

But if your insomnia is severe or affecting your quality of life, your doctor may suggest other ways to manage your condition.


Dizziness was a common side effect reported in Nplate studies, but it was usually mild and manageable. Keep in mind there may be other causes of dizziness, such as your condition or other drugs you take.

What might help

Take extra care when standing up from sitting to avoid falls. Because you may experience dizziness when starting Nplate, be careful driving or operating machinery until you know how the drug affects you.

Dizziness may be temporary and ease with continued treatment. But if it’s ongoing or severe, talk with your doctor. They can suggest ways to help manage this side effect and determine whether you should continue with Nplate treatment.

Joint pain

Joint pain is a common side effect of Nplate. People in the drug’s studies reported joint pain and other types of pain, including muscle and shoulder pain, and pain in their extremities.

Joint pain may be caused by other health conditions such as osteoarthritis or rheumatoid arthritis. Tell your doctor if you have problems with your joints or muscles before starting Nplate treatment.

What might help

If you have joint pain with Nplate treatment, talk with your doctor. They can suggest ways to ease mild pain.Suggestions may include:

If your joint pain is ongoing or severe, your doctor may suggest other ways to manage it. In some cases, they may recommend that you stop Nplate treatment.


Nplate can cause indigestion (upset stomach). This was a common, but typically mild and temporary, side effect reported in the drug’s studies.

What might help

If you have indigestion with Nplate treatment, talk with your doctor. They can suggest ways to help manage it such as avoiding heavy, spicy meals and eating too close to bedtime.

But if you have indigestion that’s severe, with symptoms such as weight loss, black stools, or persistent abdominal pain, talk with your doctor right away. They’ll diagnose the cause and discuss treatment options with you.

Allergic reaction

Like most drugs, Nplate can cause an allergic reaction in some people. Symptoms 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 Nplate, they’ll decide if you should continue treatment.

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

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

Keeping track of side effects

During your Nplate treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start treatment with a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were using when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Taking notes and sharing them with your doctor will help them learn more about how Nplate affects you. They can then use this information to adjust your treatment plan if needed.

Nplate may not be right for you if you have certain medical conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you. Talk with your doctor about your health history before starting Nplate. Factors to consider include those described below.

Blood clots. Treatment with Nplate increases the level of platelets in your blood, which helps with clotting. But sometimes the drug can cause a dangerously high level of platelets and increase your risk of blood clots. This can increase your risk of heart attack and stroke. There isn’t enough information to know the ideal platelet level for balancing the risks of blood clots and bleeding. Your doctor will monitor you during your treatment to be sure Nplate continues to be safe for you.

Allergic reaction. If you’ve had an allergic reaction to Nplate or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other medications that might be better options.

Loss of response to Nplate. Nplate can sometimes stop working to improve or maintain the level of platelets in the body. This may happen because your immune system has inactivated the drug. Your doctor will monitor you during your treatment. If they suspect your body is not responding to the drug, they’ll likely order blood tests. If tests confirm the drug is no longer effective, your doctor will discuss other treatment options with you.

Myelodysplastic syndromes. If you have myelodysplastic syndromes (MDS), your doctor won’t prescribe Nplate for you. MDS is a group of conditions that interfere with your body’s ability to make healthy blood cells. Nplate can cause MDS to turn into acute myeloid leukemia (AML). Some people with MDS in the drug’s studies developed this kind of blood cancer during Nplate treatment.

Doctors only recommend Nplate for immune thrombocytopenia which is caused by your immune system and to increase platelet counts after radiation exposure that’s affected the bone marrow. They do not recommend the drug for thrombocytopenia caused by MDS or for other causes of low platelet counts.

Alcohol and Nplate

There are no known interactions between Nplate and alcohol. But drinking alcohol can cause some side effects which are similar to those of Nplate, including indigestion (upset stomach) and dizziness. Before drinking alcohol, check with your doctor regarding how much (if any) is safe during your treatment.

Pregnancy and breastfeeding with Nplate

It’s unknown if Nplate treatment is safe during pregnancy or while breastfeeding. If you’re pregnant or planning to become pregnant, talk with your doctor about the safety of Nplate.

It’s unknown if the drug passes into breast milk. Your doctor will likely suggest not breastfeeding while you’re receiving Nplate treatment. This is to avoid possible risks to your child from side effects of the medication.

Nplate can cause side effects that range from mild to serious. If you have questions about side effects the drug can cause or what to expect during treatment, talk with your doctor. Examples of questions to help start the conversation include:

  • Does my risk of side effects from Nplate depend on my dosage?
  • Do I have a higher risk of side effects if I’m also taking other medications to treat my condition?
  • Is my risk of muscle and joint pain higher when I first start Nplate treatment?

To learn more about Nplate, see these articles:

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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.