Eltrombopag Olamine is indicated in Chronic Immune (Idiopathic) Thrombocytopenia, Chronic Hepatitis C-associated Thrombocytopenia, Severe Aplastic Anemia.
Eltrombopag is an orally bioavailable, small-molecule TPO-receptor agonist that interacts with the transmembrane domain of the human TPO-receptor. Eltrombopag is a stimulator of STAT and JAK phosphorylation. Unlike recombinant TPO or romiplostim, Eltrombopag does not activate the AKT pathway in any way. It should be noted that when given to patients with aplastic anemia, other lineages besides platelet count were increased, suggesting that either eltrombopag enhanced the effect of TPO in vivo; or there is a yet uncovered mechanism of action at work.
Dosage & Administration
Chronic Immune (Idiopathic) Thrombocytopenia-
- Adult and Pediatric Patients 6 Years and Older with ITP: Initiate Eltrombopag at a dose of 50 mg once daily, except in patients who are of East Asian ancestry (such as Chinese, Japanese, Taiwanese or Korean) or who have mild to severe hepatic impairment (Child-Pugh Class A,B,C). For patients of East Asian ancestry with ITP, initiate Eltrombopag at a reduced dose of 25 mg once daily. For patients with ITP and mild, moderate or severe hepatic impairment (Child-Pugh Class A,B,C), initiate Eltrombopag at a reduced dose of 25 mg once daily.
- For patients of East Asian ancestry with ITP and hepatic impairment (Child-Pugh Class A,B,C), consider initiating Eltrombopag at a reduced dose of 12.5 mg once daily. Pediatric Patients with ITP Aged 1 to 5 Years: Initiate Eltrombopag at a dose of 25 mg once daily.
Chronic Hepatitis C-associated Thrombocytopenia-
- Initiate Eltrombopag at a dose of 25 mg once daily. Monitoring and Dose Adjustment: Adjust the dose of Eltrombopag in 25-mg increments every 2 weeks as necessary to achieve the target platelet count required to initiate antiviral therapy. Monitor platelet counts every week prior to starting antiviral therapy. During antiviral therapy, adjust the dose of Eltrombopag to avoid dose reductions of Peginterferon. Monitor CBCs with differentials, including platelet counts, weekly during antiviral therapy until a stable platelet count is achieved. Monitor platelet counts monthly thereafter. Do not exceed a dose of 100 mg daily. Monitor clinical hematology and liver tests regularly throughout therapy with Eltrombopag.
Severe Aplastic Anemia-
- Initiate Eltrombopag at a dose of 50 mg once daily. For patients with severe aplastic anemia of East Asian ancestry or those with mild, moderate or severe hepatic impairment (Child-Pugh Class A,B,C), initiate Eltrombopag at a reduced dose of 25 mg once daily.
The most common side effects of Eltrombopag in adults when used to treat chronic ITP are: In adult patients with ITP, the most common adverse reactions (greater than or equal to 5% and greater than placebo) were: nausea, diarrhea, upper respiratory tract infection, vomiting, increased ALT, myalgia and urinary tract infection. In pediatric patients age 1 year and older with ITP, the most common adverse reactions (greater than or equal to 10% and greater than placebo) were upper respiratory tract infection and nasopharyngitis.
In patients with chronic hepatitis C-associated thrombocytopenia, the most common adverse reactions (greater than or equal to 10% and greater than placebo) were: anemia, pyrexia, fatigue, headache, nausea, diarrhea, decreased appetite, influenza-like illness, asthenia, insomnia, cough, pruritus, chills, myalgia, alopecia and peripheral edema. In patients with severe aplastic anemia, the most common adverse reactions (greater than or equal to 20%) were: nausea, fatigue, cough, diarrhea and headache.
Pregnancy & Lactation
Pregnancy Category C. There are no adequate and well controlled studies of Eltrombopag usein pregnancy. In animal reproduction and developmental toxicity studies, there was evidence ofembryolethality and reduced fetal weights at maternally toxic doses. Eltrombopag should beused in pregnancy only if the potential benefit to the mother justifies the potential risk to thefetus.
Nursing Mothers: It is not known whether Eltrombopag is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Eltrombopag, a decision should be made whether to discontinue nursing or to discontinue Eltrombopag taking into account the importance of Eltrombopag to the mother.
Precautions & Warnings
Hepatotoxicity: Monitor liver function before and during therapy.
Thrombotic or Thromboembolic Complications: Portal vein thrombosis has been reported in patients with chronic liver disease receiving Eltrombopag. Monitor platelet counts regularly.
Use in Special Populations
Pediatric Use:The safety and efficacy of Eltrombopag in pediatric patients 1 year and older with chronic ITP were evaluated in two double-blind, placebo-controlled. The pharmacokinetics of Eltrombopag has been evaluated in 168 pediatric patients 1 year and older with ITP dosed once daily for dosing recommendations for pediatric patients 1 year and older. The safety and efficacy ofEltrombopag in pediatric patients younger than 1 year with ITP have not yet been established. The safety and efficacy of Eltrombopag in pediatric patients with thrombocytopenia associated with chronic hepatitis C and severe aplastic anemia have not been established.
Geriatric Use: Of the 106 patients in two randomized clinical trials of Eltrombopag 50 mg in chronic ITP, 22% were 65 years of age and over, while 9% were 75 years of age and over. In the two randomized clinical trials of Eltrombopag in patients with chronic hepatitis C and thrombocytopenia, 7% were 65 years of age and over, while fewer than 1% were 75 years of age and over. No overall differences in safety or effectiveness were observed between these patients and younger patients in the placebo-controlled trials, but greater sensitivity of some older individuals cannot be ruled out.
Hepatic Impairment: Hepatic impairment influences the exposure of Eltrombopag. Reduce the initial dose of Eltrombopag in patients with chronic ITP (adult and pediatric patients 6 years and older only) or severe aplastic anemia who also have hepatic impairment (Child-Pugh Class A, B, C). No dosage adjustment is necessary for patients with chronic hepatitis C and hepatic impairment.
Renal Impairment: No adjustment in the initial dose of Eltrombopag is needed for patients with renal impairment. Closely monitor patients with impaired renal function when administering Eltrombopag.
In the event of overdose, platelet counts may increase excessively and result in thrombotic/thromboembolic complications.
In one report, a subject who ingested 5,000 mg of Eltrombopag had a platelet count increase to a maximum of 929 x 109/L at 13 days following the ingestion. The patient also experienced rash, bradycardia, ALT/AST elevations and fatigue. The patient was treated with gastric lavage, oral Lactulose, Intravenous fluids, Omeprazole, Atropine, Furosemide, Calcium, Dexamethasone, andPlasmapheresis; however, the abnormal platelet count and liver test abnormalities persisted for 3 weeks. After 2 months follow-up, all events had resolved without sequelae.
In case of an overdose, consider oral administration of a metal cation-containing preparation, such as Calcium, Aluminum, or Magnesium preparations to chelate Eltrombopag and thus limit absorption. Closely monitor platelet counts. Reinitiate treatment with Eltrombopag in accordance with dosing and administration recommendations.