Romiplostim

Romiplostim is a prescription medication used for the treatment of chronic immune thrombocytopenia and hematopoietic syndrome associated with acute radiation syndrome.

• Romiplostim is available under the following different brand names: Nplate

Adult and pediatric dosage

Injection, lyophilized powder for reconstitution

• 125mcg/vial
• 250mcg/vial
• 500mcg/vial

Chronic Immune Thrombocytopenia

Adult and pediatric dosage

Initial

• 1 mcg/kg SC qWeek  
• Use the lowest dose of Nplate to achieve and maintain a platelet count above 50 x 109/L as necessary to reduce the risk for bleeding

Dose adjustment

• Adjust weekly dose by increments of 1 mcg/kg until platelet count above 50 x 109/L as necessary to reduce the risk for bleeding; not to exceed the maximum weekly dose of 10 mcg/kg
• Median dose of 2 mcg/kg in clinical studies
• Determine dose adjustment by platelet count
• Platelets less than 50 x 109/L: Increase by 1 mcg/kg
• Platelet above 200 to below 400 x 109/L for 2 consecutive weeks: Reduce by 1 mcg/kg
• Platelet above 400 x 109/L: Do not give dose; continue weekly platelet assessment, if platelets fall to below 200 x 109/L, resume at a dose reduced by 1 mcg/kg
• Discontinue if platelet count does not increase to a sufficient level to avoid clinically important bleeding after 4 weeks at 10 mcg/kg

Hematopoietic Syndrome of Acute Radiation Syndrome

Adult and pediatric dosage

• 10 mcg/kg SC x 1 dose
• Administer as soon as possible after suspected or confirmed exposure to radiation levels above 2 grays (Gy)

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

Common side effects of Romiplostim include:

• bruising,
• headache,
• dizziness,
• joint pain, muscle weakness or tenderness,
• pain in the arms, legs, or shoulder,
• numbness or tingling in the hands or feet,
• trouble sleeping,
• stomach pain, indigestion, nausea, vomiting, diarrhea,
• cough, wheezing, chest tightness, trouble breathing,
• stuffy nose, sneezing, sinus pain, or
• pain in the mouth and throat.

Serious side effects of Romiplostim include:

• severe or ongoing diarrhea,
• purple or red spots under the skin,
• signs of an ear infection (more common in children)--fever, ear pain or full feeling, trouble hearing, drainage from the ear, fussiness in a child,
• signs of a stroke--sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, balance problems,
• signs of a blood clot in the lung--chest pain, sudden cough, wheezing, rapid breathing, coughing up blood, or
• signs of a blood clot in the leg--swelling, warmth, or redness in an arm or leg.

Rare side effects of Romiplostim include:

• none 

This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Romiplostim has no noted severe interactions with any other drugs.
• Romiplostim has no noted serious interactions with any other drugs.
• Romiplostim has no noted moderate interactions with any other drugs.
• Romiplostim has no noted minor interactions with any other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Romiplostim?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Romiplostim?”

Cautions

• Progression from myelodysplastic syndromes (MDS) to acute myelogenous leukemia (AML) observed in adult clinical trials; not indicated for thrombocytopenia due to MDS or any cause of thrombocytopenia other than chronic ITP
• Thrombotic/thromboembolic complications may result from increased platelet counts; portal vein thrombosis reported; to minimize risk, in patients with ITP; do not use romiplostim as an attempt to normalize platelet counts; follow dosage guidelines; use caution in patients with a history of cerebrovascular disease
• Hyporesponsiveness or failure to maintain platelet response should prompt searching for causative factors, including neutralizing antibodies to romiplostim; discontinue if platelet count does not increase to level to avoid clinically important bleeding after 4 weeks of highest weekly dose (i.e., 10 mcg/kg/week)
• Upon discontinuation of therapy, rebound thrombocytopenia and risk of bleeding may develop; monitor CBCs and platelet counts weekly for at least 2 weeks following discontinuation
• May increase risk for bone marrow reticulin formation or progression, which may improve upon discontinuation of therapy
• In absence of myelosuppression induced by acute exposure to radiation, the administration might cause excessive increases in platelet counts and may cause thrombotic and thromboembolic complications

Pregnancy and Lactation

• Based on findings from animal reproduction studies, fetal harm may occur when administered to pregnant females
• Limited available data in pregnant females are insufficient to inform a drug-associated risk of adverse developmental outcomes.
• Lactation
  • No information is available on the presence of drugs in human milk, effects on the breastfed child, or milk production
  • Human IgG is present in human milk, but published data suggest that breast milk antibodies do not enter neonatal and infant circulation in substantial amounts
  • Advise women not to breastfeed during treatment