Pharmacologic class: Hematologic drug
Therapeutic class: Antiplatelet drug
Pregnancy risk category C
Unclear. May reduce platelet production by decreasing megakaryocytic hypermaturation, thereby decreasing platelet count and inhibiting platelet aggregation (at higher doses).
Capsules: 0.5 mg, 1 mg
Indications and dosages
➣ Essential thrombocythemia
Adults: 0.5 mg P.O. q.i.d. or 1 mg P.O. b.i.d. for 1 week. Adjust as needed to lowest effective dosage that maintains platelet count below 600,000/mm3. Maximum dosage is 10 mg daily or 2.5 mg as a single dose.
• Hepatic or renal disease
• Prolonged exposure to sunlight
• Women who are or may become pregnant
Use cautiously in:
• renal, hepatic, or cardiac dysfunction
• pregnant or breastfeeding patients
• children younger than age 16.
• Give 1 hour before or 2 hours after meals.
CNS: amnesia, confusion, depression, dizziness, drowsiness, weakness, headache, syncope, insomnia, migraine, nervousness, pain, paresthesia, malaise, seizures, cerebrovascular accident
CV: angina, chest pain, hypertension, palpitations, orthostatic hypotension, peripheral edema, vasodilation, arrhythmias, tachycardia, heart failure, hemorrhage, myocardial infarction, cardiomyopathy, cardiomegaly, atrial fibrillation, complete heart block, pericarditis
EENT: amblyopia, abnormal or double vision, visual field abnormalities, tinnitus, epistaxis, rhinitis, sinusitis
GI: nausea, vomiting, diarrhea, constipation, abdominal pain, melena, gastric or duodenal ulcers, dyspepsia, aphthous stomatitis, anorexia, flatulence, gastritis, pancreatitis, GI hemorrhage
GU: painful urination, hematuria
Hematologic: lymphadenoma, bleeding tendency, anemia, thrombocytopenia
Musculoskeletal: leg cramps; joint, back, muscle, neck pain
Respiratory: bronchitis, dyspnea, pneumonia, respiratory disease, asthma, pulmonary infiltrates, pulmonary fibrosis, pulmonary hypertension
Skin: bruising, pruritus, rash, alopecia, urticaria, skin disease, photosensitivity reaction
Other: chills, fever, flulike symptoms, edema
Drug-drug. Sucralfate: interference with anagrelide absorption
Drug-diagnostic tests. Hemoglobin, platelets: decreased values
Hepatic enzymes: elevated values
Drug-food. Any food: decreased drug bioavailability
Drug-herbs. Evening primrose oil, feverfew, garlic, ginger, ginkgo biloba, ginseng, grapeseed: increased antiplatelet effect
☞ Watch for signs and symptoms of vasodilation, heart failure, and arrhythmias in patients with cardiovascular disease.
• For first 2 weeks, monitor CBC and liver and kidney function test results.
• Monitor platelet count regularly until maintenance dosage is established.
• Check regularly for adverse reactions, especially bleeding tendency.
• Monitor blood pressure for orthostatic hypertension.
• Instruct patient to take drug 1 hour before or 2 hours after meals.
• Tell patient that drug may cause a temporary blood pressure decrease if he sits or stands up suddenly. Tell him to rise slowly and carefully.
☞ Instruct patient to report unusual bleeding or bruising or difficulty breathing.
☞ Tell patient to avoid prolonged exposure to sunlight.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.
• Inform patient using hormonal contraceptives that drug may interfere with contraceptive efficacy. Advise her to use alternative birth control method.
• Tell patient to avoid activities that may cause injury. Tell him to use soft toothbrush and electric razor to avoid gum and skin injury.
• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
• Notify patient that he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.