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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epoetin (recombinant human erythropoietin) is a sialoglycoprotein hormone that appears to be immunologically and biologically equivalent to the endogenous compound, enhancing erythropoiesis dose-proportionally. The therapeutic efficacy of epoetin in the treatment of anaemia associated with chronic renal failure has been established, with almost all patients responding with increases in haematocrit and haemoglobin levels, and improvements in quality of life. Some patients demonstrate relative epoetin resistance and require a higher dosage to achieve target haemoglobin and haematocrit levels. Maintenance of an adequate iron supply is essential and iron supplementation is recommended if serum ferritin is below 100 to 150 micrograms/L or transferrin saturation is less than 20%. The incidence of serious adverse effects may be reduced by maintaining a moderate rate of increase in the haematocrit with close monitoring of blood pressure and dialysis efficacy. Individual titration of epoetin dosage is recommended, with increases made in small increments to achieve haematocrit and haemoglobin levels of 30 to 33% and 10 to 12 g/dl, respectively, although the optimal haematocrit for each patient should be individually determined. Some patients will also require a modest increase in heparin dosage because of a possible increase in clotting tendency. Hypertension is the most common adverse effect in patients with chronic renal failure, occurring partially as a result of increasing blood viscosity and peripheral vascular resistance with the correction of anaemia. Maintenance epoetin therapy has been given for more than 2 years without a decrease in responsiveness and does not appear to adversely affect the outcome of renal transplantation. Thus, epoetin represents a significant therapeutic advance in the treatment of anaemia associated with chronic renal failure and should be considered a first option for these patients. Its potential value in the treatment of anaemia associated with other disorders and in facilitating autologous blood donation remains to be fully determined.
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PMID:Epoetin (recombinant human erythropoietin). A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in anaemia and the stimulation of erythropoiesis. 269 45

The quality of life was assessed in 37 maintenance hemodialysis patients during treatment with recombinant human erythropoietin (r-HuEPO; EPOGEN [epoetin alfa], AMGEN Inc, Thousand Oaks, CA) for correction of anemia. All patients experienced an increase in hematocrit level. The mean hematocrit level in the study population was 19.8% before therapy and 31.5% after therapy. Eighty-four percent of patients reported an increase in their sense of well-being. Better appetite was subjectively noted by 81% of patients. Improvements in sexual function (62%), socializing (70%), sleep (68%), and skin color (51%) were also noted. An increase in exercise capacity was reported by 78% of patients; objective measurements showed that the mean value of VO2max in a subgroup of 11 patients increased by 50% after treatment. The Karnofsky score calculated in 29 patients showed improvement in all patients except those aged greater than 70 years. The group mean Karnofsky score increased from 76 before to 86.6 after therapy, indicating that with r-HuEPO treatment subjects were able to exert themselves to perform ordinary activities. Before therapy 14 of the patients were unemployed; after therapy only two did not work. Those side effects that occurred, predominantly iron deficiencies, hypertension, and hyperkalemia, were controlled by appropriate clinical management. Treatment with r-HuEPO does improve the quality of life and ability to work of uremic patients and does not adversely affect their transplant potential.
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PMID:Improvements in quality of life following treatment with r-HuEPO in anemic hemodialysis patients. 275 25

Recombinant human erythropoietin is a major advance in the management of patients with chronic renal failure. The sustained dose-dependent rise in haematocrit which it produces effectively abolishes symptoms of anaemia, but at the cost of an increase in blood viscosity. This in turn predisposes to increased vascular resistance and the development of hypertension. Over half of all deaths of patients with end-stage renal failure are from cardiovascular disease, notably myocardial infarction, heart failure, and stroke, for which hypertension is a known risk factor. Erythropoietin-related increases in blood pressure are therefore of particular concern, and seem to be most severe in previously hypertensive patients. There is now a need to establish the optimum rate and extent of rise of haematocrit required to alleviate symptoms without incurring undue risk.
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PMID:Hypertension, blood viscosity, and cardiovascular morbidity in renal failure: implications of erythropoietin therapy. 289 90

An autosomal erythrocytosis, inherited as a dominant, occurred in seven members of a family. The propositus was first diagnosed as having erythrocytosis at 26 years of age. He had headaches and marked plethora. Polycythaemia vera and secondary erythrocytosis of known cause were excluded. Erythropoietin level was not elevated. Two of his three children were also found to have erythrocytosis. As in this family, the disease is characterized in middle age by hypertension, cardiovascular and thromboembolic phenomena, as well as abnormal bleeding. For over eight years the propositus has been successfully treated with repeated venous blood lettings.
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PMID:[Idiopathic familial erythrocytosis. Report on a family with autosomal dominant inheritance]. 337 Dec 13

Tissue hypoxia is the main stimulus of erythropoietin production. Erythropoietin stimulates erythropoiesis by acting on medullary stem cells. Unlike healthy subjects adjusting to high altitude, patients with chronic respiratory failure do not always develop polycythaemia. In those who do, the physiopathology of polycythaemia remains unknown. It seems to be due to insufficient action more than to insufficient production of erythropoietin. Most authors agree that polycythaemia is harmful when the haematocrit exceeds 60%. The most commonly used corrective method nowadays is phlebotomy. Blood withdrawal is effective on clinical symptoms and on pulmonary arterial hypertension, but not on blood gases and ventilatory parameters at rest or during exercise.
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PMID:[Polycythemia in patients with chronic respiratory insufficiency]. 378 62

We present here results of studies on four patients (three men, one woman) who had had cadaver renal transplants and in whom renal artery stenosis and hypertension developed. Erythropoietin-dependent erythrocytosis developed in association with these changes in the three men. All patients had stable renal function and the hypertension was well controlled. Absolute erythrocytosis thought to be secondary to local renal hypoxia due to decreased renal blood flow developed in two of the men. Erythrocytosis developed in the other man but his RBC mass was at the upper limit of normal. In these patients, we suspect that the erythropoietin-dependent erythrocytosis is secondary to intrarenal hypoxia due to renal artery stenosis. Erythrocytosis or elevated erythropoietin levels failed to develop in the woman despite severe renal artery stenosis. Possible reasons for this discrepancy are discussed.
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PMID:Renal artery stenosis with erythrocytosis after renal transplantation. 699 30

Erythropoietin, a glycoprotein, is synthesized mainly in the kidney. With the destruction of renal tissue, erythropoietin production decreases; this is a major factor in the development of anemia in patients with renal failure. For about ten years now, recombinant human erythropoietin has been available for the treatment of renal anemia. All patients with renal insufficiency, independent of their plan for future renal replacement therapy, may benefit from erythropoietin. At what extent of anemia erythropoietin therapy should be started is still discussed and is certainly dependent on the degree of the patient's impairment by his anemia. Before beginning a therapy with erythropoietin, other forms of anemia observed in patients with renal failure, i.e. mainly iron deficiency, have to be excluded. A strict monitoring of hematocrit during treatment with erythropoietin is mandatory. Hypertension, seizures and cardiovascular complications have been observed with overdosing of erythropoietin. Special emphasis of this review is therefore put on the discussion of the dynamics of the erythropoietin-red cell system.
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PMID:[Erythropoietin, a milestone in the history of nephrology]. 748 78

Epoetin alfa is a recombinant form of erythropoietin, a glycoprotein hormone which stimulates red blood cell production by stimulating the activity of erythroid progenitor cells. This review discusses the use of the drug in the management of anaemia in diseases often associated with advancing age [renal failure, cancer, rheumatoid arthritis (RA) and other chronic diseases, and the myelodysplastic syndromes (MDS)] and in surgical patients. Intravenous and subcutaneous therapy with epoetin alfa raises haematocrit and haemoglobin levels, and reduces transfusion requirements, in anaemic patients with end-stage renal failure undergoing haemodialysis or peritoneal dialysis. The drug is also effective in the correction of anaemia in patients with chronic renal failure not yet requiring dialysis and does not appear to affect renal haemodynamics adversely or to precipitate the onset of end-stage renal failure. Response rates of 32 to 82% with epoetin alfa therapy have been reported in patients with anaemia associated with cancer or cytotoxic chemotherapy. Limited data in patients with anaemia associated with RA show correction of anaemia after epoetin alfa treatment. Response rates to the drug of 0 to 56% have been noted in patients with MDS. Epoetin alfa also reduces anaemia, increases the capacity for autologous blood donation and reduces the need for allogeneic blood transfusion in patients scheduled to undergo surgery. Hypertension occurs in 30 to 35% of patients with end-stage renal failure who receive epoetin alfa, but this can be managed successfully with correction of fluid status and antihypertensive medication where necessary, and is minimised by avoiding rapid increases in haematocrit. Although vascular access thrombosis has not been conclusively linked to therapy with the drug, increased heparinisation may be required when it is administered to patients on haemodialysis. Epoetin alfa does not appear to exert any direct cerebrovascular adverse effects. Thus, epoetin alfa is a well established and effective therapy for the management of anaemia associated with renal failure. It also improves haematocrit and quality of life in patients with anaemia associated with cancer or chemotherapy. Epoetin alfa increases the capacity for blood donation and reduces the decrease in haematocrit seen in patients donating autologous blood prior to surgery. It also reduces, but may not eliminate, the need for allogeneic blood transfusion.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Epoetin alfa. A review of its clinical efficacy in the management of anaemia associated with renal failure and chronic disease and its use in surgical patients. 757 84

Erythropoietin (EPO) therapy in haemodialysis patients may be associated with the development of hypertension and vascular access thrombosis. Raised levels of fibrinogen and von Willebrand factor have been implicated in the pathophysiology of thrombosis under these circumstances. The effect of nifedipine, used to treat EPO therapy-related hypertension, on levels of fibrinogen and von Willebrand factor antigen (vWf) was studied in a group of 21 EPO-treated haemodialysis patients. Significant increments in both fibrinogen and vWf following EPO therapy were observed in the 13 patients who did not receive nifedipine (fibrinogen (median range), pre-EPO: 3.73 (2.41-6.38) mg/ml, post-EPO: 4.59 (3.03-8.80) mg/ml, P < 0.05; vWf pre-EPO: 183 (118-374)% normal, post-EPO: 253 (124-392)% normal, P < 0.01). Similar changes were not seen in the eight nifedipine-treated patients (fibrinogen, pre-EPO: 3.35 (2.58-6.32) mg/ml, post-EPO: 3.36 (2.69-7.20) mg/ml, P = NS; vWf, pre-EPO: 176 (104-298)% normal, post-EPO: 175 (82-371)% normal, P = NS). These effects were independent of blood pressure control. The use of nifedipine to treat EPO therapy-related hypertension may therefore potentially help to reduce the risk of vascular access thrombosis.
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PMID:Effect of nifedipine on changes in fibrinogen and von Willebrand factor in haemodialysis patients treated with recombinant human erythropoietin. 760 73

Erythropoietin was administered to five anemic azotemic diabetic subjects for 1 year to assess the effect of increasing red cell mass on clinical well-being and the course of renal functional decline. None of the subjects manifested worsened hypertension or cerebrovascular or cardiovascular complications despite an increase in mean hematocrit from a baseline mean of 29.6% to a mean of 39.5%. The serum creatinine concentration after 1 year of treatment with erythropoietin was 3.7 mg/dL, which was unchanged from the baseline value of 3.5 mg/dL. Plasma viscosity remained constant as red cell mass increased. Although the viscosity of whole blood rose as the hematocrit increased, it was within the range of normal blood viscosity for an equivalent hematocrit. The favorable impact of erythropoietin treatment on three diabetic subjects who had macular edema and anemia is described. One hypothesis to explain the benefit of a raised hematocrit on both diabetic nephropathy and retinopathy is that the metabolic, hormonal, and hemodynamic components of the diabetic syndrome, in concert, produce tissue and cellular hypoxia that is ameliorated in part by the greater oxygen-transporting capacity of a raised red cell mass. The pseudohypoxia of diabetes may be implicated in the pathogenesis of diabetic neuropathy, retinopathy, muscular dysfunction, and nephropathy.
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PMID:Erythropoietin in diabetic macular edema and renal insufficiency. 761 Dec 53


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