How is Nplate administered?
Medically reviewed by N. France, BPharm. Last updated on April 19, 2021.
Nplate (romiplostim) is a once-weekly subcutaneous injection that is administered by your healthcare provider and which is used to treat thrombocytopenia in certain patients with immune thrombocytopenia (ITP) who have not responded well enough to corticosteroids, immunoglobulins or splenectomy.
How is Nplate prepared?
To prepare your Nplate injection your healthcare provider will reconstitute the Nplate powder which comes in a vial. Water for Injection, USP, used alone or in combination with 0.9% Sodium Chloride Injection, USP, is used to reconstitute the powder.
The Nplate vial is swirled and inverted gently to make sure the powder is dissolved, but it should not be shaken.
How will I receive Nplate?
Your healthcare provider will use a syringe to draw up the required dose of Nplate from the vial containing the reconstituted powder. It will then be injected under your skin (subcutaneously) at one of three recommended injection sites including the:
- Front of the middle thighs
- Stomach (abdomen) except for the 2 inch (5 cm) area around the belly button
- Outer area of the upper arms
Your healthcare provider will use a syringe that has 0.01ml graduations to inject Nplate because the dose you need may be very small.
The usual starting dose when treating ITP is Nplate 1 mcg per kg. The dose is adjusted slowly until a platelet count of ≥ 50x109/L is achieved and maintained. The maximum weekly dose is 10 mcg per kg.
During the dose adjustment phase of therapy, your healthcare provider will check your platelet count before each injection to determine the dose of Nplate you need. Your Nplate dose will be adjusted based on how your platelets respond to treatment if you are an adult. Body weight is also used to help determine the required dose of Nplate in children and it is recommended that a child's weight be checked every 12 weeks. Once your healthcare provider has determined what your regular dose of Nplate should be a blood test is only required once a month.
Blood tests are also required for at least two weeks after treatment with Nplate is stopped to check your platelet counts aren’t dropping too low.
NPlate (10 mcg per kg) is also administered as a one-off treatment to increase survival in people acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, HS-ARS).
- Food and Drug Administration. Nplate. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/125268s168lbl.pdf. [Accessed April 19, 2021].
- Nplate. Nplate (romiplostim) 101. Available from: https://www.nplate.com/platelet-booster#getting-nplate. [Accessed April 19, 2021].