Nplate is a brand-name prescription medication. It’s approved to treat a condition called immune thrombocytopenia (ITP).

With ITP, your body destroys blood cells called platelets. These cells are needed to help your blood form clots. ITP causes you to have a low level of platelets. As a result, your blood is slow to clot. With ITP, you can bleed and bruise more easily than usual.

Nplate is approved to increase platelet counts in:

  • adults with ITP that hasn’t improved after treatment with either:
    • immunoglobulin (a blood product that affects how your immune system works), or
  • children ages 1 year and older who’ve had ITP for at least 6 months, and whose ITP hasn’t improved after treatment with either corticosteroids, immunoglobulins, or a splenectomy

Nplate is only approved to increase low platelet counts caused by ITP. It’s not approved to treat low platelet counts caused by any other condition.

Nplate contains the active drug romiplostim. It works by stimulating your bone marrow to make more platelets. Nplate is a type of drug called a thrombopoietin receptor agonist.

Nplate comes in single-dose vials. It’s available in three strengths: 125 mcg, 250 mcg, and 500 mcg. Nplate is given as a weekly injection under your skin (called a subcutaneous injection). These injections are given by a doctor or nurse in a healthcare facility.

Effectiveness

Several clinical studies have found Nplate effective in increasing platelet counts and reducing the risk of bleeding in people with ITP.

One 24-week study compared Nplate with a placebo (treatment with no active drug). This study looked at adults who’d already tried at least one other treatment for their ITP (not including splenectomy). Nplate was used to increase people’s platelets to a level that helped lower their risk of bleeding. (This level is about 50,000 platelets per microliter [mcL] of blood).

In this study:

  • 88% of adults who took Nplate had an average platelet count of at least 50,000 platelets/mcL of blood for either:
    • any 4 weeks of the study, or
    • any 6 of the last 8 weeks of the study
  • 14% of adults who took the placebo had the same result

For more information about the effectiveness of Nplate, please see the “Nplate for ITP” section below.

Nplate is available only as a brand-name medication. It’s not currently available in generic form. A generic drug is an exact copy of the active drug in a brand-name medication. It’s usually less expensive than the brand-name version.

Nplate contains the active drug romiplostim.

Nplate can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Nplate. These lists do not include all possible side effects.

For more information on the possible side effects of Nplate, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs they’ve approved. If you would like to report to the FDA a side effect you’ve had with Nplate, you can do so through MedWatch.

Mild side effects

The mild side effects of Nplate that are more common* in adults can include:

  • pain in your joints, muscles, shoulders, arms, or legs
  • belly pain
  • indigestion
  • dizziness
  • feeling pins and needles in your hands and feet
  • insomnia (trouble sleeping)
  • headache
  • upper respiratory infections, such as the common cold
  • cough
  • bronchitis
  • sinusitis
  • nausea and vomiting
  • diarrhea
  • pain in your mouth and throat

* occurred in at least 5% of adults in clinical studies

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Nplate aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects, which are explained in more detail below in “Side effect details,” include:

Side effects in children

In clinical studies, the most common side effects in children who took Nplate were as follows.

  • Bruising. This side effect occurred in 41% of children who took Nplate. In comparison, bruising occurred in 33% of children who took a placebo (treatment with no active drug).
  • Upper respiratory infections (URIs). These infections, such as the common cold, occurred in 31% of children who took Nplate. In comparison, URIs occurred in 25% of children who took a placebo.
  • Mouth and throat pain. This side effect occurred in 25% of children who took Nplate. In comparison, 4% of children who took a placebo had mouth and throat pain.

If you have concerns about side effects of Nplate in children taking the drug, talk with your child’s doctor.

Side effect details

You may wonder how often certain side effects occur with this drug. Here’s some detail on some of the side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Nplate. But it’s not known how often this happens with Nplate.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness 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
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Nplate. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Joint and muscle pain

It’s possible to have pain in your joints or muscles while you’re using Nplate.

In clinical studies, 26% of adults who took Nplate had joint pain. In comparison, joint pain occurred in 20% of adults who took a placebo (treatment with no active drug). And 14% of adults who took Nplate had muscle pain, while only 2% of adults who took the placebo had muscle pain.

If you have joint or muscle pain while you’re taking Nplate, talk with your doctor or pharmacist. They may be able to recommend medications to help reduce your pain.

Dizziness

It’s possible to feel dizzy during treatment with Nplate. If you do feel dizzy, you should avoid driving or using other machinery.

In clinical studies, 17% of adults who took Nplate had dizziness. But no adults who took the placebo (treatment with no active drug) had this side effect.

If you feel dizzy while you’re taking Nplate, talk with your doctor. They can suggest ways to help manage this side effect.

Blood clots

Nplate is used to increase platelet counts in people with certain conditions. But if Nplate makes your platelet count rise too much (called thrombocytosis), the drug can increase your risk of serious blood clots.

These clots can form inside certain blood vessels in your body, resulting in:

In clinical studies, thrombocytosis occurred in 2% of adults who took Nplate for 1 year. But it’s not clear how often blood clots occur in people who take Nplate.

When you first start treatment with Nplate, your doctor will order a blood test for you each week. This lets them monitor your platelet count. They’ll adjust your dosage of Nplate based on the result of this test. This is how they’ll make sure your platelet count doesn’t get too high during treatment.

Once your platelet count and your Nplate dosage are both stable, your doctor will check your platelet count each month.

If you’re concerned about the risk of having blood clots during Nplate treatment, talk with your doctor. They can discuss with you the risks and benefits of treatment.

Bone marrow changes

Using Nplate may increase the amount of reticulin in your bone marrow. (Reticulin is a type of connective tissue.)

Increased reticulin can sometimes progress into bone marrow fibrosis. With this condition, scar tissue develops in your bone marrow. But it’s not known for sure if this condition happens with Nplate.

You’ll have blood tests done regularly during Nplate treatment. If your blood tests show any problems with your blood cells, your doctor may want to check your bone marrow.

If certain tests show that the amount of reticulin is increasing in your bone marrow, your doctor may recommend that you stop using Nplate. This change in your bone marrow may improve after you stop Nplate treatment.

If you’re concerned about the risk of bone marrow changes with Nplate, talk with your doctor. They can discuss with you the risks and benefits of treatment.

Hair loss (not a side effect)

During clinical studies, hair loss wasn’t reported in people using Nplate treatment.

If you have hair loss or you’re concerned about hair loss while you’re taking Nplate, talk with your doctor. They can recommend ways to help manage this side effect.

The Nplate dosage your doctor prescribes to treat immune thrombocytopenia (ITP) will depend on these factors:

Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Nplate comes in single-dose vials that hold a powdered form of the drug. Nplate is available in three strengths: 125 micrograms (mcg), 250 mcg, and 500 mcg.

Your healthcare provider will add liquid to the vials of Nplate to dissolve the powder. Then, they’ll give the medication to you as an injection under your skin (called a subcutaneous injection).

Dosage for ITP

The typical dosage of Nplate for ITP is one injection given each week.

For your first injection, the usual dose of Nplate for adults is 1 mcg of drug per kilogram (kg) of body weight. (One kilogram is equal to about 2.2 pounds.)

For the rest of your injections, your Nplate dose will be calculated based on your platelet counts.

During the start of your Nplate treatment, you’ll have a blood test to check your platelet count every week until your dosage is stable. (After your platelet count is stable, blood tests will be done monthly.) Your weekly Nplate dose will be increased by 1 mcg/kg each week, until your platelet count is at least 50,000 platelets per microliter (mcL) of blood.

Until your platelet count is stable, your weekly dosage will be adjusted as follows:

  • If your platelet count is lower than 50,000 platelets/mcL, your dosage will be increased by 1 mcg/kg.
  • If your platelet count has been between 200,000 and 400,000 platelets/mcL for 2 weeks in a row, your dosage will be reduced by 1 mcg/kg.
  • If your platelet count is higher than 400,000 platelets/mcL, you won’t have a dose of Nplate that week. Instead, your platelet count will be checked every week, until it falls to below 200,000 platelets/mcL. At that point, you’ll start receiving Nplate again, but at a dosage that’s reduced by 1 mcg/kg.

Once your platelet count is stable at a level that’s right for you, your weekly dose of Nplate will stay the same. At this point, your platelet count will usually only be checked once a month.

The maximum weekly dosage of Nplate is 10 mcg/kg. However, most people reach and maintain stable platelet counts of about 50,000 platelets/mcL with a weekly dosage that’s lower than this. If after 4 weeks of treatment at the maximum dose, you don’t reach a platelet level that helps you avoid major bleeding, your doctor will recommend that you stop using Nplate.

Pediatric dosage

The dosage of Nplate to treat ITP in children is the same as it is for adults. For more information, see the section titled “Dosage for ITP,” which is located just above.

Note: Keep in mind that there’s one additional consideration for children’s Nplate dosing. Children using the drug should be weighed every 12 weeks. This helps to make sure their dosage, which is based on their body weight, stays correct over the course of treatment when the children may be growing.

What if I miss a dose?

If you miss an appointment to have your weekly injection of Nplate, call your healthcare provider’s office as soon as possible. The medical staff will help reschedule your appointment.

To help make sure that you don’t miss a dose, try setting a reminder on your phone.

Will I need to use this drug long term?

Nplate is meant to be used as a long-term treatment. If you and your doctor determine that Nplate is safe and effective for you, you’ll likely take it long term.

The Food and Drug Administration (FDA) approves prescription drugs such as Nplate to treat certain conditions. Nplate is FDA-approved to treat immune thrombocytopenia, which is also called ITP. (This condition used to be called idiopathic thrombocytopenic purpura.)

About ITP

With ITP, your immune system causes your spleen to destroy blood cells called platelets. These cells are needed to help your blood form clots. ITP causes you to have low levels of platelets. This means your blood is slow to clot. With ITP, you can bruise or bleed more easily than normal.

Common symptoms of ITP include purpura (many purple bruises on your skin or inside your mouth). Your bruises may also look more like a rash, made up of small, pinpoint-sized, red or purple dots.

Other common symptoms include nosebleeds, bleeding gums, and in women, heavy periods. More serious internal bleeding is also possible.

Nplate and ITP

Nplate works by stimulating your bone marrow to make more platelets. This reduces your risk of bleeding.

Nplate is approved to increase platelet counts in:

  • adults with ITP that hasn’t improved after treatment with either:
    • immunoglobulin (a blood product that affects how your immune system works), or
  • children ages 1 year and older who’ve had ITP for at least 6 months and whose ITP hasn’t improved with either corticosteroids, immunoglobulins, or a splenectomy

Nplate is only FDA-approved to increase low platelet counts caused by ITP. It’s not approved to treat low platelet counts caused by any other condition.

Normal platelet counts are typically between 150,000 platelets per microliter (mcL) and 450,000 platelets/mcL.

Nplate is used to increase your platelet count to a level that helps lower your risk of bleeding. (This level is about 50,000 platelets/mcL.) The drug is not meant to bring your platelet count back to a normal level.

Nplate’s effectiveness for ITP

Clinical studies have found Nplate effective in increasing platelet counts and reducing the risk of bleeding in people with ITP. For example, two 24-week studies compared Nplate with a placebo (treatment with no active drug).

These studies looked at adults who’d already tried at least one other treatment for their ITP. One study looked at people who’d had a splenectomy, and the other study looked at people who still had their spleen. At the start of the study, all of the people had a platelet count of 30,000 platelets/mcL or lower.

The researchers reported on the following areas:

  • How many people had a long-lasting response to treatment (called a durable platelet response). In this study, a durable platelet response was an average platelet count of at least 50,000 platelets/mcL for any 6 of the last 8 weeks of the study.
  • How many people had an overall platelet response to treatment. This included people who had a durable platelet response. And it also included people who had an average platelet count of at least 50,000 platelets/mcL for any 4 weeks of the study.
  • How many people needed rescue treatment to reduce bleeding.
  • How many people had an immediate risk of bleeding during the study

Results from these studies are described below.

Nplate’s effectiveness without splenectomy

In the study of adults who hadn’t had a splenectomy:

  • 61% of people who took Nplate had a durable platelet response; in comparison, 5% of people who took a placebo had the same result.
  • 88% of people who took Nplate had an overall platelet response; in comparison, 14% of people who took a placebo had the same result.
  • On average, people who took Nplate had 15 weeks out of 24 weeks in which their platelet count was at least 50,000/mcL.
  • Over the 24-week study, 20% of people who took Nplate needed rescue treatment, compared with 62% of people who took a placebo.

Nplate’s effectiveness after splenectomy

In the study of adults who’d had a splenectomy:

  • 38% of people who took Nplate had a durable platelet response; in comparison, none of the people who took a placebo had a durable platelet response.
  • 79% of people who took Nplate had an overall platelet response; in comparison, none of the people who took a placebo had an overall platelet response
  • On average, people who took Nplate had 12 weeks out of 24 weeks in which their platelet count was at least 50,000/mcL.
  • Over the 24-week study, 26% of people who took Nplate needed rescue treatment, compared with 57% of people who took a placebo.

Nplate and children

Nplate is FDA-approved to increase platelet counts in children ages 1 year and older. It’s given to children who’ve had ITP for at least 6 months. For this use, the children’s ITP hasn’t responded to past treatment with either corticosteroids, immunoglobulins, or a splenectomy.

For more information about this use, see the section above called “Nplate for ITP.”

Effectiveness in children

Nplate has been effective in treating IPT in children during clinical studies.

One 24-week study and one 12-week study looked at Nplate treatment in children ages 1 year and over. The studies compared treatment with Nplate to treatment with a placebo (no active drug). The children included had already tried at least one other treatment for their ITP. At the beginning of the study, all of the children had a platelet count of 30,000/mcL or lower.

In the 24-week study:

  • 52% of children who took Nplate had a durable platelet response*; in comparison, 10% of children who took a placebo had the same result.
  • 71% of children who took Nplate had an overall platelet response**; in comparison, 20% of children who took a placebo had the same result.
  • On average, children who took Nplate had 12 weeks out of 24 weeks in which their platelet count was at least 50,000/mcL.

In the 12-week study:

  • 82% of children who took Nplate had a platelet response of 50,000/mcL for 2 weeks in a row; in comparison, no children who took the placebo had this result.

*A durable platelet response was an average platelet count of at least 50,000 platelets/mcL for any 6 of the last 8 weeks of the study.

**An overall platelet response to treatment included both children who had a durable platelet response and children who had an average platelet count of at least 50,000 platelets/μL for any 4 weeks of the study.

The Food and Drug Administration (FDA) approves prescription drugs such as Nplate to treat certain conditions. Nplate is approved to treat immune thrombocytopenia (ITP) in certain people (see the section just above called “Nplate for ITP”). But the drug may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Nplate for aplastic anemia

Nplate isn’t FDA-approved to treat aplastic anemia. But the drug has also been used off-label to increase platelet counts in people with aplastic anemia.

With this condition, your bone marrow doesn’t make enough new blood cells. Aplastic anemia causes low levels of all your blood cell types (red blood cells, white blood cells, and platelets). The most common cause of aplastic anemia is your immune system mistakenly attacking certain cells in your bone marrow.

While Nplate isn’t approved to treat this condition, a different drug in the same class as Nplate is approved for it. This other drug is called eltrombopag (Promacta). And it’s approved to increase platelet counts in people with aplastic anemia.

A 2019 study suggested that Nplate may be effective in increasing platelet counts in people with aplastic anemia. However, further research is needed because this particular study was small in size.

If you have questions about treatment options for aplastic anemia, talk with your doctor.

Nplate for other uses in children

Nplate is FDA-approved to increase platelet counts in children ages 1 year and older who’ve had ITP for at least 6 months.

However, according to another 2019 study, Nplate has been given off-label for other uses in a small number of children. For example, the drug has been used to increase platelet counts in children with the following conditions:

  • ITP that’s been present for less than 6 months
  • neonatal alloimmune thrombocytopenia (low platelet count in a newborn that’s caused by the mother’s immune system attacking the baby’s platelets)
  • hereditary thrombocytopenia (a genetic disorder that causes low platelet counts)
  • thrombocytopenia (low platelet count) that’s caused by chemotherapy or a bone marrow transplant

More research is needed to know how effective Nplate is for these uses. If you have questions about using Nplate for any of these uses, talk with your or your child’s doctor.

Nplate may be used with other routine treatments that are given for immune thrombocytopenia (ITP). In addition, rescue treatments may sometimes be used along with Nplate.

Nplate and routine ITP treatments

While you’re taking Nplate, you may need to take other routine ITP treatments, such as corticosteroids*, as well. Routine treatments are treatments that are used consistently over a period of time to treat your ITP.

For some people, taking Nplate allows them to take a lower dose than usual of their other routine medications, such as corticosteroids. Or they may be able to stop using their routine medications altogether.

However, do not make any changes to your treatment plan unless your doctor instructs you to do so.

Talk with your doctor about whether you’ll still need to use routine treatments while you’re taking Nplate.

*Corticosteroids are a class of drugs that lower the activity of your immune system. This action helps to stop your immune system from attacking your platelets.

Nplate and rescue ITP treatments

While you’re taking Nplate, you may need rescue treatments for your ITP. This is sometimes the case if your platelet count needs to be quickly increased. This situation could happen if you have severe bleeding that needs to be controlled or if you need to have surgery.

Rescue treatments include:

  • intravenous* immunoglobulin** (called IVIg)
  • anti-D immunoglobulin**
  • platelet transfusion (receiving platelets that were collected from someone else’s body or from your body at an early point in time)

*With intravenous (IV) infusion, the drug is injected into your vein over a period of time.

**Immunoglobulins are immune system proteins.

Talk with your doctor about whether you may need any rescue treatments while you’re taking Nplate.

Nplate is used to treat immune thrombocytopenia (ITP). With this condition, your immune system mistakenly starts attacking certain cells in your body.

What happens with ITP

With ITP, your immune system starts to make antibodies (certain proteins) that attach to your platelets. (Platelets are blood cells that help your blood form clots.) Once antibodies mark the platelets, the platelets are destroyed by your spleen. This lowers the number of platelets in your blood. With ITP, your immune system also reduces the number of platelets that are normally made in your bone marrow.

Platelets are essential for helping your body to form blood clots. For example, if a blood vessel is cut or damaged, platelets clump together to form a plug that helps stop the bleeding. Platelets also activate a chain reaction that ultimately forms a clot around the clump of platelets.

If you have low levels of platelets in your body, your blood is slow to form clots. And you can bruise and bleed more easily than usual.

Normal platelet counts are typically between 150,000 platelets per microliter (mcL) and 450,000 platelets/mcL.

But if you have ITP, your platelet count is typically below 100,000/mcL.

What Nplate does

Nplate is a type of drug called a thrombopoietin receptor agonist. It works by increasing the number of platelets made in your bone marrow.

Bone marrow is a spongy substance inside your bones. And it’s the location where all of your blood cells are made. Different hormones in your body tell your bone marrow to make different types of blood cells.

For example, the hormone thrombopoietin (TPO) tells certain cells in your bone marrow to make platelets. TPO also tells your bone marrow to release the platelets into your bloodstream. The hormone does this by attaching to specific proteins called TPO receptors. These receptors are found on the surface of cells that make platelets.

Nplate mimics the effect of natural TPO in your body. Nplate attaches to and activates TPO receptors in the same way that the natural hormone does. This causes the platelet-making cells in your bone marrow to produce and release platelets.

Nplate is used to increase the number of platelets your body makes, until your platelet count reaches about 50,000/mcL. At this level, your risk of bleeding is reduced.

But if Nplate increases your platelet count too much, it can raise your risk of getting blood clots. So, because of this, the drug isn’t used to increase your platelets to a level that’s considered normal.

How long does it take to work?

How long Nplate takes to work can vary from person to person. But for some people, Nplate may start to increase your platelet count after your first dose of the drug. You’re unlikely to notice this, but certain blood tests will show that your platelet count has gone up.

In a clinical study, 50% of people taking Nplate reached an average platelet count of 50,000/mcL within 2 to 3 weeks of starting treatment.

You should take Nplate according to your doctor or healthcare provider’s instructions.

Nplate is given as an injection under your skin (called a subcutaneous injection). Your doctor or nurse will administer the injection in a healthcare facility.

Subcutaneous injections are typically given in the following areas:

  • your belly
  • your upper arms
  • your thighs

When it’s administered

Nplate is given once a week, on the same day each week.

To help make sure that you don’t miss an appointment for your injection, try setting a reminder on your phone.

Other drugs are available that can treat immune thrombocytopenia (ITP). Some may be a better fit for you than others. If you’re interested in finding an alternative to Nplate, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed below are used off-label to treat these specific conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Examples of drugs that may be used to treat ITP include:

  • avatrombopag (Doptelet)
  • eltrombopag (Promacta)
  • fostamatinib (Tavalisse)
  • prednisone (Rayos)
  • rituximab (Rituxan)
  • danazol (Danocrine)
  • intravenous* immunoglobulin** (IVIg)
  • anti-D immunoglobulin**
  • cyclophosphamide (Cytoxan)
  • azathioprine (Imuran, Azasan)
  • mycophenolate (CellCept)

* With intravenous (IV) infusion, the drug is injected into your vein over a period of time.

** Immunoglobulins are immune system proteins.

You may wonder how Nplate compares with other medications that are prescribed for similar uses. Here we look at how Nplate and Promacta are alike and different.

Ingredients

Nplate contains the active drug romiplostim, while Promacta contains the active drug eltrombopag. Both medications belong to a class of drugs called thrombopoietin receptor agonists. (A class of drugs is a group of medications that work in a similar way.)

Uses

Nplate and Promacta are both approved to increase platelet counts in people with immune thrombocytopenia (ITP). With this condition, your immune system mistakenly starts attacking your platelets. ITP can cause you to bleed and bruise more easily than normal.

These drugs are approved for use in adults with ITP that hasn’t improved with certain other treatments. These treatments include:

  • corticosteroids (drugs used to lower the activity of your immune system),
  • immunoglobulin (a blood product that affects how your immune system works), or
  • splenectomy (surgery to remove your spleen)

For this use, both Nplate and Promacta are also approved for use in children ages 1 year and older who’ve had ITP for at least 6 months.

In addition, Promacta is also approved to treat:

  • Thrombocytopenia (low platelet count). For this use, Promacta is given to adults with chronic (long-term) hepatitis C. The drug is prescribed to increase platelet counts both before and during treatment with another drug called interferon.
  • Severe aplastic anemia. With this condition, your bone marrow doesn’t make enough new blood cells. For this use, Promacta can be given as first-line treatment* in combination with immunosuppressant drugs (drugs that lower the activity of your immune system). Or Promacta can be used for aplastic anemia that hasn’t improved with immunosuppressants in the past. Promacta is approved to treat severe aplastic anemia in adults and children ages 2 years and over.

*With first-line treatment, Promacta is the first drug given to treat the condition.

Drug forms and administration

Nplate is given as an injection under your skin (called a subcutaneous injection). The injection is given once a week by a doctor or nurse, in a healthcare facility.

On the other hand, Promacta comes as a tablet and as a powder that’s made into a suspension. These forms are each taken by mouth once a day.

It’s important to note that eltrombopag, the active drug in Promacta, is also available in some countries as the brand-name drug Revolade. However, Revolade hasn’t been approved for use in the United States.

Side effects and risks

Nplate and Promacta both contain a similar type of drug. These medications can cause some similar and some different side effects. Below are examples of these side effects.

Mild side effects

These lists contain examples of mild side effects that can occur with Nplate, with Promacta, or with both drugs (when taken individually).

  • Can occur with Nplate:
    • pain in your joints, shoulders, arms, or legs
    • belly pain
    • indigestion
    • dizziness
    • sinusitis
    • cough
  • Can occur with Promacta:
  • Can occur with both Nplate and Promacta:
    • upper respiratory infections, such as the common cold
    • nausea and vomiting
    • diarrhea
    • pain in your mouth and throat
    • headache
    • muscle pain
    • feeling pins and needles in your hands and feet

Serious side effects

These lists contain examples of serious side effects that can occur with Nplate, with Promacta, or with both drugs (when taken individually).

*Promacta has a boxed warning for new or worsening liver problems. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Effectiveness

Nplate and Promacta have different approved uses. But they’re both used to increase platelet counts in adults and children ages 1 year and older with ITP.

These drugs haven’t been directly compared in clinical studies. But reviews of both studies in adults and studies in children found these drugs to be similarly effective in treating ITP.

In addition, a 2019 review of studies done in adults found Nplate to be slightly more effective than Promacta in treating ITP. But this review also found that Promacta was a reasonable alternative to Nplate.

Your doctor can recommend which of these drugs is a better option for your treatment.

Costs

Nplate and Promacta are both brand-name drugs. There are currently no generic forms of either drug. Brand-name medications usually cost more than generics.

You can view cost estimates for either drug on GoodRx.com. But the actual price you’ll pay for either Nplate or Promacta depends on your prescribed dosage and your insurance coverage.

Like Promacta, other drugs are prescribed for uses similar to those of Nplate. Here we look at how Nplate and Doptelet are alike and different.

Ingredients

Nplate contains the active drug romiplostim, while Doptelet contains the active drug avatrombopag. Both medications belong to a class of drugs called thrombopoietin receptor agonists. (A class of drugs is a group of medications that work in a similar way.)

Uses

Nplate and Doptelet are both approved to increase platelet counts in people with immune thrombocytopenia (ITP). With this condition, your immune system mistakenly starts attacking your platelets. ITP can cause you to bleed and bruise more easily than normal.

These drugs are approved for use in adults with ITP that hasn’t improved with certain other treatments. These treatments include:

  • corticosteroids (drugs used to lower the activity of your immune system),
  • immunoglobulin (a blood product that affects how your immune system works), or
  • splenectomy (surgery to remove your spleen)

In addition, Nplate is also approved for this use in children ages 1 year and older who’ve had ITP for at least 6 months.

Doptelet is also approved to treat thrombocytopenia (low platelet count) in adults with chronic (long-term) liver disease. For this use, the drug is given to increase platelet counts before certain procedures that have a risk of bleeding.

Drug forms and administration

Nplate is given as an injection under your skin (called a subcutaneous injection). The injection is given once a week by a doctor or nurse, in a healthcare facility.

Doptelet, on the other hand, comes as a tablet that’s taken by mouth once a day.

Side effects and risks

Nplate and Doptelet both contain a similar type of drug. These medications can cause very similar side effects. Below are examples of these side effects.

Mild side effects

These lists contain examples of mild side effects that can occur with Nplate, with Doptelet, or with both drugs (when taken individually).

  • Can occur with Nplate:
    • pain in your muscles, shoulders, arms, or legs
    • belly pain
    • indigestion
    • dizziness
    • feeling pins and needles in your hands and feet
    • cough
    • sinusitis
    • nausea and vomiting
    • diarrhea
    • pain in your mouth and throat
  • Can occur with Doptelet:
    • fatigue (lack of energy)
    • bruising
    • nosebleeds
    • bleeding gums
  • Can occur with both Nplate and Doptelet:
    • headache
    • upper respiratory infections, such as the common cold
    • joint pain

Serious side effects

These lists contain examples of serious side effects that can occur with Nplate, or with both Nplate and Doptelet (when taken individually).

Effectiveness

Nplate and Doptelet have different FDA-approved uses, but they’re both used to increase platelet counts in adults with ITP.

These drugs haven’t been directly compared in clinical studies. One review of studies found Nplate to be slightly more effective in treating ITP than Doptelet is. But this review also found that Doptelet was a reasonable alternative to Nplate.

Your doctor can recommend which of these drugs is a better fit for you.

Costs

Nplate and Doptelet are both brand-name drugs. There are currently no generic forms of either drug. Brand-name medications usually cost more than generics.

You can view cost estimates for either drug on WellRx.com. But the actual price you’ll pay for either Nplate or Doptelet depends on your dosage and your insurance coverage.

Alcohol hasn’t been reported to interact with Nplate. However, regularly drinking large amounts of alcohol can cause low platelet counts. Nplate is used to treat immune thrombocytopenia (ITP), which is a condition that also causes low platelet counts.

Talk with your doctor about whether it’s safe for you to drink alcohol while you’re taking Nplate.

There aren’t any medications, herbs, or supplements that have been reported to interact with Nplate.

Drug interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

However, before taking Nplate, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

As with all medications, the cost of Nplate can vary.

The actual price you’ll pay will depend on your insurance plan, your location, and the medical facility where you receive Nplate.

Your insurance plan may require you to get prior authorization before they approve coverage for Nplate. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the request and let you and your doctor know if your plan will cover Nplate.

If you’re not sure if you’ll need to get prior authorization for Nplate, contact your insurance plan.

Financial and insurance assistance

If you need financial support to pay for Nplate, or if you need help understanding your insurance coverage, help is available.

Amgen, the manufacturer of Nplate, offers a program called Nplate Navigator that can help provide information to you about the cost and financial assistance available for Nplate. For more information and to find out if you’re eligible for support, call 855-7Nplate (855-767-5283) or visit the program website.

It’s not known if Nplate is safe to take during pregnancy. Studies of Nplate in pregnant animals found that the drug can harm fetuses when it’s used during pregnancy. However, animal studies don’t always predict what will happen in humans.

It’s also important to note that if your platelet count is very low toward the end of pregnancy, you have an increased risk of severe bleeding during or after childbirth. (Nplate is used to treat immune thrombocytopenia (ITP), which causes low platelet counts.)

If you’re pregnant or planning to become pregnant, talk with your doctor about the possible risks and benefits of using Nplate.

It’s not known if Nplate is safe to take during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Nplate.

It’s not known for sure if Nplate passes into breast milk. However, because the drug can possibly cause serious side effects in a child who’s breastfed, you shouldn’t breastfeed while taking it.

If you’re breastfeeding, talk with your doctor about safe and healthy ways to feed your child while you’re taking Nplate.

Here are answers to some frequently asked questions about Nplate.

Will I have to change my diet while I’m using Nplate?

No, you shouldn’t need to change your diet. The manufacturer of Nplate hasn’t recommended any dietary restrictions during Nplate treatment. In fact, food doesn’t affect the way Nplate works in your body.

During Nplate treatment, you should be able to continue with your usual diet unless your doctor recommends otherwise.

Does Nplate cure ITP?

No, Nplate doesn’t cure immune thrombocytopenia (ITP). Because Nplate doesn’t remove the cause of ITP, it can’t cure the condition. However, Nplate can be taken long term to help manage the condition. Nplate does this by increasing your platelets to a stable level that reduces your risk of bleeding.

Is Nplate a steroid?

No, Nplate isn’t a steroid. Steroids (also called corticosteroids) are medications that lower the activity of your immune system. Steroids can be used for ITP to help stop your immune system from attacking your platelets. (With ITP, your immune system attacks your platelets and leads to low platelet counts.)

However, Nplate is a different type of drug. It’s called a thrombopoietin receptor agonist. Nplate works to treat ITP by stimulating your bone marrow to make more platelets.

How often will I need to have lab tests done while I’m taking Nplate?

When you first start treatment with Nplate, you’ll need to have blood tests done every week. Your doctor will order a test called a complete blood count (CBC). This test lets your doctor check the levels of all your blood cells, including platelets.

Your doctor will adjust your weekly Nplate dosage based on your platelet counts. When your platelet count and weekly Nplate dosage are both stable, you’ll have blood tests done once a month.

Once you’ve completed Nplate treatment, you’ll need to have blood tests every week for 2 weeks. This is done to make sure that your platelet count doesn’t drop too low after you stop using the drug.

If you have questions about the lab tests you’ll need during Nplate treatment, talk with your doctor.

Before taking Nplate, talk with your doctor about your health history. Nplate may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Myelodysplastic syndrome (MDS). If you have MDS (a certain form of bone marrow cancer), you shouldn’t take Nplate. Doing so could cause your MDS to get worse and develop into a type of blood cell cancer called acute myeloid leukemia (AML). If you have MDS, talk with your doctor before using Nplate.
  • Bone marrow problems. Nplate can sometimes cause an increased amount of reticulin (a type of connective tissue) to develop in your bone marrow. This change could lead to abnormal blood cells, or fewer healthy blood cells, being made by your bone marrow. If you already have any problems with your bone marrow, talk with your doctor about whether Nplate is right for you. If you take Nplate, your doctor will monitor your blood cells. If any problems develop, your doctor may want to check your bone marrow. In some cases, they may recommend that you stop Nplate treatment.
  • Risk of blood clots. It’s possible that Nplate may cause your platelet count to become too high. If this happens, your risk of blood clots is increased. If you’ve had a blood clot in the past, or you have other risk factors for blood clots, talk with your doctor about whether Nplate is right for you. (If you take Nplate, your doctor will monitor your platelet count and adjust your dose of Nplate based on the result. This helps your doctor to make sure that your platelet count doesn’t get too high.)
  • Chronic (long-term) liver disease. If Nplate causes your platelet count to become too high, the risk of getting a blood clot in your portal vein is increased for people with chronic liver disease. (The portal vein moves blood from your spleen and intestine into your liver.) A blood clot in this vein can cause your spleen to enlarge. It can also cause varicose veins to develop in your esophagus and stomach. Your doctor will monitor your platelet count and adjust your dosage of Nplate based on the result. This helps your doctor to make sure that your platelet count doesn’t get too high.
  • Pregnancy. It’s not known if Nplate is safe to take during pregnancy. For more information, please see the “Nplate and pregnancy” section above.
  • Breastfeeding. Nplate may pass into breast milk. Do not take Nplate if you’re breastfeeding. For more information, please see the “Nplate and breastfeeding” section above.

Note: For more information about the potential negative effects of Nplate, see the “Nplate side effects” section above.

The following information is provided for clinicians and other healthcare professionals.

Indications

Nplate is approved to treat immune thrombocytopenia (ITP) in:

  • adults with ITP that hasn’t improved with either corticosteroids, immunoglobulins, or a splenectomy
  • children ages 1 year and over who’ve had ITP for at least 6 months, and whose ITP hasn’t improved with either corticosteroids, immunoglobulins, or a splenectomy

Nplate should only be used to treat ITP in people with an increased risk of bleeding either due to their degree of thrombocytopenia or to co-existing clinical conditions.

Nplate should only be used to increase platelet counts to about 50,000 per microliter (mcL). It is not meant to normalize platelet counts.

Nplate is only approved to increase platelet counts in people with ITP. It’s not approved to treat low platelet counts caused by any other condition.

Mechanism of action

Nplate contains romiplostim, a thrombopoietin receptor agonist. Romiplostim activates the thrombopoietin receptor on megakaryocytes in the bone marrow. This increases the production and release of platelets. The drug helps platelet production to outweigh the platelet destruction caused with ITP, which leads to increased platelet counts.

Pharmacokinetics and metabolism

After subcutaneous administration, the maximum concentration (Cmax) of romiplostim is reached between 7 hours and 50 hours post-dose.

Blood concentrations of romiplostim do not correlate with the dose administered. For this reason, the dosing guide is based on platelet counts in individual patients.

The half-life of romiplostim varies from 1 day to 34 days.

Contraindications

Nplate has no contraindications. However, it shouldn’t be used to increase platelet counts in people with myelodysplastic syndromes (MDS). This is due to an increased risk of progression of MDS to acute myeloid leukemia (AML) as seen in clinical studies with Nplate.

Storage

Before use, Nplate vials can be stored:

  • in a refrigerator at a temperature of 36°F to 46°F (2°C to 8°C), until the expiration date listed on the vial
  • at room temperature (up to 77°F or 25°C), for up to 30 days; if not used within 30 days, discard Nplate, do not place it back into the refrigerator

Nplate that has been reconstituted with sterile water for injection, but hasn’t been further diluted, can be kept:

  • in the original vial at room temperature (up to 77°F or 25°C) for up to 24 hours after reconstitution
  • in the original vial in a refrigerator, at a temperature of 36°F to 46°F (2°C to 8°C), for up to 24 hours after reconstitution
  • in a syringe at room temperature (up to 77°F or 25°C) for up to 4 hours after reconstitution

Nplate that has been reconstituted with sterile water for injection, followed by further dilution with 0.9% sodium chloride injection, can be kept:

  • in the original vial in a refrigerator, at a temperature of 36°F to 46°F (2°C to 8°C), for up to 4 hours before administration
  • in a syringe at room temperature (up to 77°F or 25°C) for up to 4 hours before administration

Protect Nplate from light. Do not shake or freeze vials of the medication.

Disclaimer: Medical News Today 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.