Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-lowering therapy in myeloproliferative disorders includes cytostatic drugs, mainly hydroxyurea, interferon alpha, and anagrelide. Anagrelide is the latest addition to the therapeutic arsenal, and the basis for its use is reviewed. The platelet-lowering efficacy is 70 to 80% in essential thrombocythemia, and the response is rapid; most of the patients reach the treatment goal within a few weeks. Side effects are common, mainly caused by the vascular effects, and include palpitation, headache, loose stools/diarrhea, and edema. Some side effects are time-limited, but late dropout from therapy is not uncommon. The total dropout rate in prospective studies is 30 to 50%. Pharmacologic treatment of side effects is often helpful. Cardiac insufficiency may be worsened in patients with previous heart failure, and special caution is warranted in such patients. Anagrelide has recently been registered in Europe as a second-line therapy in ET but is often used as first-line therapy in the United States, especially in younger patients, due to the concern about increased leukemia risk with cytostatic treatment. The first randomized anagrelide study, with its limitations, gives support for the second-line registration. Given that dose escalation is a problem in some patients with all therapeutic agents used, combination of two drugs in lower doses is a practical option already used by many clinicians without basis in any published study.
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PMID:Anagrelide treatment in myeloproliferative disorders. 1667 80

(1) For patients aged over 60 years who have essential thrombocythaemia, and are considered to be at increased risk of thromboembolism, the standard cytotoxic agent is hydroxycarbamide (hydroxyurea), which reduces the risk of thrombocytosis but adversely affects other blood cell lines. It may also increase the risk of progression to cancer. (2) Anagrelide, initially studied as an antiplatelet drug, was approved in Europe for the treatment of essential thrombocythaemia in high-risk patients when other treatments fail or are poorly tolerated. (3) Evaluation data includes a trial versus hydroxycarbamide that was prematurely halted because of an excess of cardiovascular events among patients on anagrelide. Among 809 patients who were also receiving aspirin as an antithrombotic (and who may not have met strict criteria for essential thrombocythaemia), arterial or venous thrombosis and haemorrhage were significantly more frequent with anagrelide, during a median follow-up of 39 months (55 versus 36 patients). (4) According to the results of 3 non comparative trials involving about 500 patients, and the European Medicines Agency report analysing these and other study populations, anagrelide reduces the platelet count to below 600 times 10 to the 9th power/litre in two-thirds of patients. No data are available on the clinical implications of this reduction in platelets. (5) Between 10% and 20% of patients treated with anagrelide experience cardiovascular adverse effects (palpitations, myocardial infarction, heart failure) or neurological adverse effects (headache, stroke, transient ischaemic attack). Gastrointestinal disturbances are also frequent (diarrhoea, nausea, abdominal pain, pancreatitis). Some of these adverse effects can be fatal. (6) Follow-up is too short to show whether anagrelide affects the risk of progression to cancer. (7) In practice, anagrelide has a less favourable risk-benefit balance than hydroxycarbamide, which remains the first-line cytotoxic agent in this setting. Anagrelide therapy can be considered if hydroxycarbamide fails or is poorly tolerated, provided patients are included in a long-term clinical trial.
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PMID:Anagrelide: new drug. Essential thrombocythaemia: further evaluation needed for this last-resort treatment. 1676 90

Essential thrombocythaemia (ET) is an acquired myeloproliferative disorder with a prolonged clinical course and a near-normal life expectancy. Therapy is stratified according to risk of thrombohaemorrhagic events. In high-risk patients, platelet reduction is generally recommended. In intermediate-risk patients, therapy should be considered depending on the severity of associated risk factors, especially cardiovascular. In low-risk patients, a watch-and-wait approach is appropriate. Hydroxycarbamide is generally first-line therapy. Concerns for possible leukemogenicity make anagrelide or interferon-alpha possible choices in younger patients and those who are resistant or intolerant to hydroxycarbamide. Each pharmacotherapy is associated with specific long-term risks and benefits. The potential risk of major bleeding is the main drawback of aspirin. Hydroxycarbamide is an established, effective drug for ET, but it may increase the risk of transformation to acute myeloid leukaemia and may give mucocutaneous ulcers. Anagrelide is a licensed treatment that also reduces platelet counts and is generally well tolerated, with evidence that some common side effects diminish over time. Anagrelide can have cardiac effects due to inhibition of phosphodiesterase III and therefore requires cautious use in patients with cardiac insufficiency. There is no evidence of leukaemogenicity with anagrelide or interferon-alpha therapy. Interferon-alpha is the only treatment suitable for use during pregnancy, although it is not licensed in ET. While it is effective for platelet reduction, the use of interferon-alpha is restricted by psychiatric side effects. Our knowledge of the optimum pharmacotherapy for each patient with ET continues to evolve through research and clinical trials, particularly into the molecular basis of the disease.
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PMID:Long-term management of thrombocytosis in essential thrombocythaemia. 1862 98