Key takeaways

  • Nplate (romiplostim) injections are typically given once per week to treat low platelet counts in adults and some children.
  • The dose of Nplate is based on weight. Depending on the condition you’re receiving it to treat, Nplate’s starting dose may range from 1 to 10 micrograms (mcg) per kilogram (kg) of body weight.
  • Nplate comes as a powder that a healthcare professional will reconstitute (mix with a sterile liquid) before injection.

Nplate is used in adults and certain children to treat low platelet count from the following conditions:

This article describes the dosages of Nplate, as well as its strengths and how it’s given.

This section describes the usual dosages of Nplate. Keep reading to learn more.

Nplate form

Nplate comes as a powder in single-use vials. The powder is mixed with sterile water to make a liquid solution. (In small children, it’s further diluted with saline.) A doctor or another healthcare professional injects the liquid solution under the skin.

Nplate strengths

Nplate comes in three strengths: 125 mcg, 250 mcg, and 500 mcg.

Your doctor will start you on the recommended dosage of Nplate that provides the desired effect. Your dosage depends on the cause of the low platelet count. Your dosage for repeat treatments will also change, depending on your platelet count each week.

The information below describes dosages that are commonly used or recommended. But your doctor will determine the best dosage to fit your needs.

Dosage for immune thrombocytopenia

Doctors dose Nplate by body weight. Your first dose of Nplate for ITP is likely to be 1 mcg of Nplate for every kg of body weight. One kg is approximately 2.2 pounds (lb).

You’ll usually receive repeat injections once per week. Each week before your injection, your doctor will order a complete blood count to check your platelet count. Depending on your platelet count, your doctor may increase or decrease your dosage, or they may delay your injection by another week.

The maximum recommended weekly dose is 10 mcg of Nplate for every kg of body weight.

Dosage for low platelets from radiation

For treatment of low platelet count following radiation exposure, you’ll receive 10 mcg of Nplate for every kg of body weight. This is a one-time treatment. Doctors recommend that you receive this dose as soon as possible after the radiation exposure.

Doctors can also prescribe Nplate for children with a low platelet count from ITP or radiation exposure.

Dosage for immune thrombocytopenia

Nplate may be prescribed for children ages 1 year and older for the treatment of ITP.

As in adults, Nplate is dosed by body weight. The first dose will be 1 mcg of Nplate for each kg of your child’s body weight.

Injections will be repeated every week. The dosage may be adjusted, depending on your child’s platelet count. Approximately every 12 weeks, your child’s doctor will also check their body weight and adjust the dosage as necessary.

Nplate’s maximum weekly dose is 10 mcg of Nplate for every kg of body weight.

Dosage for radiation exposure

Newborns and children who have been exposed to radiation may be treated with Nplate. The recommended dosage is a one-time dose of 10 mcg of Nplate for every kg of body weight.

For more information about Nplate’s dosage for children, talk with your child’s doctor or a pharmacist.

Nplate comes as a powder in single-dose vials. The powder is mixed with sterile water to make a liquid solution. When the calculated dose is less than 23 mcg, saline solution will also be added to the liquid solution.

Your doctor (or another healthcare professional) will inject a small amount of liquid solution under your skin.

You’ll receive these injections at your doctor’s office or another medical facility on a weekly basis.

Is Nplate used long term?

If you’re prescribed Nplate for ITP, you might receive the drug long term. This will depend on how your body responds to treatment with Nplate. It also depends on your platelet count and whether you have acute, persistent, or chronic ITP.

For example, children commonly have acute ITP. With acute ITP, platelet counts return to stable levels within 3 months. And 80% of children with ITP won’t go on to have chronic ITP (low platelet counts for more than 12 months).

Some adults also experience treatment-free remission. This means your platelet count stays within the stable range after you’ve stopped taking Nplate. (You should not stop your treatment without first discussing this with your doctor.)

If you have questions about how long you’re likely to receive Nplate to treat ITP, talk with your doctor.

Note: If you’re prescribed Nplate following radiation exposure, you’ll receive a one-time dose.

The dosage of Nplate you’re prescribed may depend on several factors. These include:

  • the type and severity of the condition the drug is being used to treat
  • your body weight
  • how your body responds to Nplate (your platelet count)

If you miss your appointment to receive Nplate, call your doctor’s office as soon as possible to reschedule.

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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.