Dosing and uses of Nplate (romiplostim)
Adult dosage forms and strengths
powder for injection
- 250mcg/vial
- 500mcg/vial
Thrombocytopenia
InitiaL
- 1 mcg/kg SC qWeek
Maintenance
- Plts <50x10³/mcL, increase dose by 1 mcg/kg qWeek
- Plts >200 x 10³/mcL for 2 consecutive weeks, reduce dose by 1 mcg/kg qWeek
- Plts >400 x 10³/mcL, do not dose; resume at dose reduced by 1 mcg/kg once Plt <200 x 10³/mcL
- Monitor: CBC and platelets prior to, during, and for 2 weeks post-last dose
- No more than 10 mcg/kg/week
- Discontinue if no clinically significant improvement after 4 weeks at 10 mcg/kg dose
Administration
Not for self-administration
Reconstitute Single-use Vial Containing
- 250 mcg deliverable drug (total content 375 mcg) in 0.72 mL sterile water for injection yields 250 mcg/0.5 mL deliverable amount
- 500 mcg deliverable drug (total content 625 mcg) in 1.2 mL sterile water for injection yields 500 mcg/mL deliverable amount
- Do NOT use bacteriostatic water for injection for reconstitution
- Gently swirl and invert to dissolve
- Reconstituted solution may be stored protected from light for 24 hr at room temperature or refridgerated
Renal Impairment
Not studied
Hepatic Impairment
Not studied
Other Indications & Uses
Thrombocytopenia
- Chronic immune thrombocytopenic purpura after insufficient response to corticosteroids, IVIG or splenectomy
- Nplate should be used only in patients with ITP whose degree of thrombocytopenia and clinical condition increase the risk for bleeding. Nplate should not be used in an attempt to normalize platelet counts
Pediatric dosage forms and strengths
<18 years: Safety and efficacy not established
Nplate (romiplostim) adverse (side) effects
>10%
Headache (35%)
Fatigue (33%)
Epistaxis (32%)
Confusion (25%)
Arthralgia (26%)
Upper respiratory infection (17%)
Dizziness (17%)
Diarrhea (17%)
Insomnia (16%)
Paresthesia (16%)
Myalgia (14%)
Nausea (13%)
Pain in extremity (13%)
Back pain (13%)
Bleeding (12%)
Abdominal pain (11%)
1-10%
Indigestion (7%)
Dyspepsia
Shoulder pain
Postmarketing Reports
Erythromelalgia
Hypersensitivity
Angioedema
Warnings
Contraindications
Hypersensitivity
Within 24 hr of receiving myelosuppressive chemotherapy or radiation therapy
>10% leukemic myeloid blasts in bone marrow or peripheral blood
Cautions
Thrombotic/thromboembolic complications may result from increases in platelet counts with therapy; portal vein thrombosis reported in patients with chronic liver disease receiving therapy
Thrombocytopenia may worsen after discontinuation; if severe thrombocytopenia develops during therapy, assess patients for the formation of neutralizing antibodies
In some patients with myelodysplastic syndrome, therapy increases blast cell counts and increases risk of progression to acute myelogenous leukemia
Not indicated for non-ITP thrombocytopenia
Renal/hepatic impairment
Caution in pre-existing heart failure, history of fluid retention, hepatic or renal impairment
Dyspnea may occur
Pregnancy and lactation
Pregnancy category: C
Lactation: Discontinue drug or do not nurse
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Nplate (romiplostim)
Mechanism of action
Fusion antibody-peptide that is a thrombopoietin receptor agonist; stimulates proliferation, differentiation, and activity of monocytes, neutrophils, eoxinophils, and macrophages
Pharmacokinetics
Peak plasma time: 1-3 hr (SC)
Onset: 7-14 days (increase in WBC)
Half-life elimination: 60 min (IV); 2.7 hr (SC)
