Pharmacologic: thrombopoietin receptor agonists
Treatment of chronic immune (idiopathic) thrombocytopenic purpura in patients who have had an inadequate response to corticosteroids, immunoglobulins, or splenectomy.
Increases platelet production by initiating proliferation and differentiation of megakaryocytes from bone marrow progenitor cells. Therapeutic Effects: Increased platelet count with reduced risk of bleeding.
Adverse Reactions/Side Effects
EENT: development/worsening of cataracts. GI: HEPATOTOXICITY. Hemat: bone marrow changes.
PHYSICAL THERAPY IMPLICATIONS
Examination and Evaluation
Be alert for signs of hepatotoxicity, including anorexia, abdominal pain, severe nausea and vomiting, yellow skin or eyes, fever, sore throat, malaise, weakness, facial edema, lethargy, and unusual bleeding or bruising. Report these signs to the physician immediately.
Assess skin periodically for red and purple patches (purpura). If successful, drug therapy should result in a decrease in the frequency and severity of these reactions.
Monitor signs of anemia (unusual fatigue, shortness of breath with exertion, bruising) that might indicate bone marrow changes. Notify physician if these signs occur.
Absorption: 52% absorbed following oral administration.
Metabolism and Excretion: Extensively metabolized; 59% eliminated in feces, 20% as unchanged drug; 31% excreted in urine as metabolites.
TIME/ACTION PROFILE (effect on platelet count)
|ROUTE ||ONSET ||PEAK ||DURATION |
|PO ||1 wk ||2 wk ||1 wk |
Contraindicated in: Lactation: Lactation.
Use Cautiously in: Myelodysplastic syndromes (may ↑ risk of hematologic malignancy); Hepatic impairment (lower initial dose may be required); Patients with East Asian ancestry (may require lower doses); Geri: Elderly patients may be more sensitive to drug effects; increase dose cautiously, consider age-related decrease in renal and hepatic function, concurrent disease states, and drug therapy; OB: Use in pregnancy only when potential maternal benefit outweighs potential risk to fetus.
Drug-Drug: ↓ availability and absorption of iron, calcium, aluminum, magnesium, selenium, and zinc by chelation; do not administer within 4 hr of medications containing these and other polyvalent cations.
Drug-Food: ↓ availability and absorption of iron, calcium, aluminum, magnesium, selenium, and zinc by chelation; do not administer within 4 hr of foods containing these and other polyvalent cations.
PO (Adults): 50 mg once daily, may be increased to achieve a platelet count of ≥50 × 10...