If you have certain conditions that affect your platelets, your doctor may prescribe Nplate. (Platelets help your blood to form clots.)

Nplate is a prescription drug that’s used in adults and some children with immune thrombocytopenia (ITP) that hasn’t improved with other treatments. (With ITP, you have a low level of platelets that’s caused by your immune system. This condition used to be called idiopathic thrombocytopenic purpura.)

It’s also prescribed for adults and children who were exposed to doses of radiation that affected their bone marrow. (Your platelets are made in your bone marrow.)

To learn more about what Nplate is used for, see the “Is Nplate used for ITP?” and “Is Nplate used for other conditions?” sections below.

Nplate basics

Nplate contains the drug romiplostim, which is a biologic medication. Biologics are made from parts of living organisms.

Nplate is not available in a biosimilar form. (Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.) Instead, romiplostim is available only as the brand-name drug Nplate.

Nplate comes as a powder that your doctor will mix into a solution. Then they’ll give the solution to you as an injection under your skin.

In this article, we describe Nplate’s uses, side effects, and more.

Like most drugs, Nplate may cause mild or serious side effects. The lists below describe some of the more common side effects that Nplate may cause. These lists don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

  • your age
  • other health conditions you have
  • other medications you may be taking

Your doctor or pharmacist can tell you more about the potential side effects of Nplate. They can also suggest ways to help reduce side effects.

Mild side effects

Here’s a short list of some of the mild side effects that Nplate can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Nplate’s medication guide.

Mild side effects of Nplate that have been reported include:

  • dizziness*
  • pain in your joints and muscles*
  • trouble sleeping
  • belly pain
  • upset stomach
  • tingling, burning, or numbness of your skin

Children may have different side effects from Nplate compared with adults. Side effects seen in children may include:

  • nose or throat infection
  • mouth and throat pain
  • bruising

Mild side effects of many drugs may go away within a few days or a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

* For more information on this side effect, see the “Side effect focus” section below.

Serious side effects

Serious side effects from Nplate can occur, but they aren’t common. If you have serious side effects from Nplate, call your doctor right away. However, if you think you’re having a medical emergency, you should call 911 or your local emergency number.

Serious side effects of Nplate that have been reported include:

* For more information on this side effect, see “Warnings” in the “What should be considered before receiving Nplate?” section below.

Side effect focus

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

Long-term side effects

If you’re taking Nplate for immune thrombocytopenia (ITP), you may have to take it long term. (With ITP, you have a low level of platelets that’s caused by your immune system.)

Studies suggest that Nplate is safe to take long term. In studies, there wasn’t a significant increase in bone marrow and blood clotting issues in people taking the drug long term.

What might help

If you need to take Nplate over a long period of time and you’re concerned about long-term side effects, talk with your doctor or pharmacist. They can talk with you about the risks and benefits of Nplate treatment.

Pain in your joints and muscles

In studies, some people had joint and muscle pain with Nplate treatment. In fact, these were common side effects of the drug.

Most of the time, people’s joint and muscle pain were mild to moderate. And they didn’t worsen over time.

What might help

If you have pain in your joints or muscles while you’re using Nplate, talk with your doctor. They may recommend over-the-counter pain relievers and home remedies, if needed.

Feeling dizzy

You might feel dizzy while you’re taking Nplate.

When receiving Nplate, notice when your dizziness occurs and how long it lasts. You must avoid driving or operating machines if you feel dizzy.

What might help

If dizziness is affecting your daily activities, tell your doctor about it. They may suggest ways to help manage your dizziness.

Allergic reaction

Some people may have an allergic reaction to Nplate.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth, swelling, or redness, or discoloration in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, typically in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.

If you have an allergic reaction to Nplate, tell your doctor right away. But if you think you’re having a medical emergency, call your doctor immediately or call 911 or your local emergency number.

Your doctor will explain how Nplate is administered. They’ll also explain how much you’ll be given and how often. Be sure to follow your doctor’s advice about your dosage.

Below are commonly used dosages, but always take the dosage your doctor prescribes.

Receiving Nplate

Your doctor will give Nplate to you as an injection under your skin.

The medication comes in a powder inside vials that contain:

  • 125 micrograms (mcg)
  • 250 mcg
  • 500 mcg

Your doctor will mix Nplate powder with sterile water to make a solution. Then, they’ll give the solution to you as an injection.

Dosage

If you’re taking Nplate for immune thrombocytopenia (ITP), your doctor will give you Nplate injections once every week.

If you’re taking Nplate because you’ve been exposed to doses of radiation that may have harmed your bone marrow, only one dose of the drug is needed. But you must receive this dose immediately after being exposed to the radiation.

Your doctor may adjust your dosing guide depending on your body’s response to Nplate. To monitor your response to Nplate, your doctor will order blood tests to check your platelet level.

To learn more about what Nplate is used for, see the “Is Nplate used for ITP?” and “Is Nplate used for other conditions?” sections below.

Receiving Nplate with other drugs

You might need to take Nplate with other medications to treat ITP. Examples of possible ITP treatments include:

Questions about taking Nplate

Below are answers to some common questions about taking Nplate.

  • What if I miss a dose of Nplate? If you miss a dose of Nplate, talk with your doctor as soon as you remember. Your doctor will tell you if you should skip the missed dose or make an appointment to receive the missed dose.
  • Will I need to use Nplate long term? If you’re receiving Nplate for ITP, you may need to take the drug long term. Your doctor will check your body’s response to Nplate during treatment. If your platelet level doesn’t increase enough to prevent bleeding after you’ve taken the maximum dose of Nplate for 4 weeks, you doctor may stop Nplate treatment. But if you’re receiving Nplate for radiation exposure, you’ll only receive one dose of the drug.
  • Should I take Nplate with food? Nplate is given by an injection under your skin. Your body’s absorption of Nplate doesn’t depend on whether you’ve eaten or not. So, you may receive Nplate injections on a full or empty stomach.
  • How long does Nplate take to work? Nplate starts working right away to increase your platelet level. When first starting Nplate, your doctor will check your platelet level. And they’ll continue to check your platelet level while you’re using Nplate. The results of these blood tests will help your doctor adjust your Nplate dosage if needed.
Questions for your doctor

You may have questions about Nplate and your treatment plan. It’s important to discuss all your concerns with your doctor.

Here are a few tips that might help guide your discussion:

  • Before your appointment, write down questions like:
    • How will Nplate affect my body, mood, or lifestyle?
  • Bring someone with you to your appointment if doing so will help you feel more comfortable.
  • If you don’t understand something related to your condition or treatment, ask your doctor to explain it to you.

Remember, your doctor and other healthcare professionals are available to help you. And they want you to get the best care possible. So, don’t be afraid to ask questions or offer feedback on your treatment.

Costs of prescription drugs can vary depending on many factors. These factors include what your insurance plan covers and which pharmacy you use. To find current prices for Nplate in your area, visit GoodRx.com.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You can also visit the Nplate manufacturer’s website to see if they have support options.

If you have a bleeding disorder called immune thrombocytopenia (ITP) your doctor may prescribe Nplate. This condition used to be called idiopathic thrombocytopenic purpura.

It’s a prescription drug used in adults and some children with ITP that hasn’t improved with other treatments. Specifically, doctors prescribe Nplate for:

  • adults with ITP that didn’t improve with other ITP treatments including:
    • immunoglobulins (immune system proteins)
  • children ages 1 year and older who’ve had ITP for at least 6 months that didn’t improve with other ITP therapies (listed above)

With ITP, you have a low level of platelets that’s caused by your immune system. (Platelets help your blood to form clots.) Without enough platelets, you may bleed inside your body or have trouble stopping a bleed from within.

If you have ITP, you may have bruises or tiny red or purple dots on your skin. Sometimes you might find bruises in your mouth. Other symptoms of ITP may include:

Nplate helps your body make more platelets. It does this by attaching to certain cells in your bone marrow. Once Nplate binds to them, the cells are activated to make platelets.

In addition to treating immune thrombocytopenia (ITP), which is described directly above, Nplate also has another use.

If you were exposed to doses of radiation that affected your bone marrow, your doctor may recommend Nplate. For this use, the drug can be given to adults and children, including newborns.

Your platelets are made in your bone marrow. So, if your bone marrow was harmed by radiation, you may have a low level of platelets.

Platelets help your blood to form clots. Without enough platelets, you may bleed inside your body or have trouble stopping a bleed from within.

Nplate helps your body make more platelets. It does this by attaching to certain cells in your bone marrow. Once Nplate binds to them, the cells are activated to make platelets.

Find answers to some commonly asked questions about Nplate.

How does Nplate work?

Nplate is a thrombopoietic receptor agonist (TPO-RA). It attaches to the TPO receptor (binding site) on a type of bone marrow cell called a megakaryocyte. By attaching to the TPO receptor, the drug activates megakaryocytes to make platelets.

Nplate’s mechanism of action mimics how your body’s natural thrombopoietin works.

By working in this way, Nplate helps to offset your low level of platelets. The goal of Nplate treatment is to have enough platelets in your body to help prevent bleeding.

Does Nplate cause hair loss?

No, hair loss isn’t a side effect of Nplate. If you have hair loss after starting Nplate, talk with your doctor. They can offer suggestions for how to manage it, such as these tips for hair loss prevention.

How does Nplate compare with Promacta?

Both Nplate and Promacta are brand-name drugs used in adults and some children with immune thrombocytopenia (ITP). (With ITP, you have a low level of platelets that’s caused by your immune system. Platelets help your blood to form clots.)

But, Nplate and Promacta also have other unique uses. To learn about Nplate’s uses, see the “Is Nplate used for ITP?” and “Is Nplate used for other uses?” sections above. To see Promacta’s uses, view its prescribing information. And for a side-by-side comparison of these drugs, see this article.

While Nplate contains the active drug romiplostim, Promacta contains the active drug eltrombopag. Unlike romiplostim, eltrombopag isn’t a biologic drug. (Biologics are made from parts of living organisms.)

Unlike Nplate, Promacta isn’t given by injection. Instead, it comes as forms you’ll take by mouth. Because the administration of Nplate and Promacta are different, their side effects may be different, too.

Aside from Promacta, another brand-name form of eltrombopag is Revolade. But this drug isn’t available for sale in the United States.

If you’d like to know more about these two medications, talk with your doctor or pharmacist.

Some important things to discuss with your doctor when considering Nplate treatment include:

  • your overall health
  • any medical conditions you may have

Tell your doctor if you’re taking other medications. This is important, as some drugs can interfere with Nplate. These and other considerations to discuss with your doctor are described below.

Interactions

Taking medications, vaccines, foods, and other things with a certain drug can affect how the drug works. These effects are called interactions.

Before receiving Nplate, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with Nplate.

Interactions with drugs or supplements

So far, there aren’t any known interactions between Nplate and drugs, vitamins, herbs, or supplements. But to be safe, before taking any medication, vitamin, herb, or supplement, talk with your doctor or pharmacist.

Warnings

Nplate may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Nplate. Factors to consider include those in the list below.

  • Blood clots. When your body starts making more platelets with Nplate treatment, your ability to form blood clots will improve. (Platelets help your blood to form clots.) But, having too much blood clotting may be dangerous. It can increase your risk of having a stroke or heart attack. There is no strict limit on the best platelet level to balance the risks of bleeding and clotting. Talk with your doctor about your risk of having blood clots with Nplate treatment.
  • Myelodysplastic syndromes. Nplate is not safe for use in people with myelodysplastic syndromes (MDS). MDS is a group of conditions that cause abnormal bone marrow and blood cells. People with MDS may have anemia (low red blood cell level), bleeding, bruising, and fatigue (lack of energy). If you have MDS and you take Nplate, you may develop a type of blood cancer called acute myeloid leukemia (AML). Nplate isn’t used for thrombocytopenia (low platelet level) that’s caused by certain conditions, such as MDS. Instead, it’s only used for immune thrombocytopenia (ITP), which is thrombocytopenia that’s caused by your immune system.
  • Allergic reaction. If you’ve had an allergic reaction to Nplate or any of its ingredients, you shouldn’t take Nplate. Ask your doctor what other medications are better options for you.
  • Loss of response to Nplate. Some people’s condition may not improve or maintain improvement with Nplate treatment. In some of these cases, the cause may be their immune system inactivating Nplate. And this can lead to severe thrombocytopenia (very low platelet level). If Nplate isn’t working for your condition, your doctor may order certain blood tests to determine if Nplate is right for you.

Use with alcohol

Some medications interact with alcohol. But Nplate isn’t one of them. However, before starting Nplate, ask your doctor or pharmacist if it’s safe for you to drink alcohol while taking this drug.

Pregnancy and breastfeeding

It’s not known for sure if Nplate is harmful for use in pregnant people. The only studies that show risks to pregnancy are animal studies. But animal studies don’t always show what will happen in people.

Nplate may cause harm if used during pregnancy. So, if you become pregnant while receiving Nplate, talk with your doctor right away.

As with pregnancy, there’s not enough information available about the effect of Nplate on breastfeeding. But, it’s possible that the drug may be harmful. So, it’s recommended that you avoid breastfeeding while receiving Nplate.

Injecting too much Nplate can cause very serious side effects. For this reason, your doctor will carefully calculate and inject your Nplate doses.

If you receive too much Nplate, your platelet level may rise too high and cause blood clotting. And increased blood clotting can cause stroke or heart attack.

What to do in case you take too much Nplate

If you receive too much Nplate, your doctor will stop Nplate injections and check your platelet level.

You’ll start receiving Nplate again only when it’s safe for you to do so.

If you have questions about receiving Nplate, talk with your doctor or pharmacist. They can tell you about other treatments you can use for your condition.

Here’s a list of articles that you might find helpful:

Additionally, some questions to ask your doctor about Nplate may include:

  • How can I continue to receive Nplate if I am traveling out of town?
  • Is there an alternative treatment for immune thrombocytopenia (ITP) that comes in a pill form?
  • If I reach a certain platelet level, can I stop receiving Nplate injections?
  • Can I inject Nplate myself?

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 other 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.