anagrelide hydrochloride

Action

Unclear. May reduce platelet production by decreasing megakaryocytic hypermaturation, thereby decreasing platelet count and inhibiting platelet aggregation (at higher doses).

Availability

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.

Dosage adjustment

• Hepatic or renal disease

Contraindications

• Prolonged exposure to sunlight

• Women who are or may become pregnant

Precautions

Use cautiously in:

• renal, hepatic, or cardiac dysfunction

• pregnant or breastfeeding patients

• children younger than age 16.

Administration

• Give 1 hour before or 2 hours after meals.

Adverse reactions

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

Metabolic: dehydration

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

Interactions

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

Patient monitoring

See 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.

Patient teaching

• 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.

See Instruct patient to report unusual bleeding or bruising or difficulty breathing.

See 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.