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

The chemistry, pharmacology, pharmacokinetics, clinical uses and efficacy, adverse effects, drug interactions, dosage and administration, and formulary considerations of epoetin are described. Erythropoietin, a glycoprotein hormone primarily synthesized in the kidney, is the chief regulator of red blood cell production. Erythropoietin concentrations increase in response to a hypoxic state, resulting in increased red blood cell formation, accelerated hemoglobin production, and premature movement of reticulocytes into the circulation. The human gene responsible for the production of erythropoietin recently was cloned, and the recombinant product--epoetin--has been made available through mass production. The apparent volume of distribution of i.v. epoetin approximates the assumed plasma volume both in healthy volunteers and in patients with chronic renal failure. Little is known about the metabolism and route of elimination of epoetin and erythropoietin. Epoetin recently was approved by the FDA for treatment of anemia associated with chronic renal failure. Clinical trials in patients receiving hemodialysis or peritoneal dialysis and in predialysis patients with renal dysfunction demonstrate epoetin's efficacy. Other potential indications include augmentation of blood production in patients enrolled in autologous blood donation programs and treatment of anemias associated with rheumatoid arthritis, sickle cell disease, acquired immunodeficiency syndrome, cancer, and premature birth. The most frequent adverse effect associated with epoetin therapy is the worsening or development of hypertension. Other adverse effects include thrombocytosis, hyperkalemia, rise in serum urea concentration, iron deficiency, and flu-like symptoms. No drug interactions with epoetin have been reported in humans. The recommended starting epoetin dosage in patients with chronic renal failure is 50-100 IU/kg three times weekly. Epoetin is available only as an injection for i.v. or s.c. administration. Epoetin provides a new therapeutic approach to the treatment of anemia associated with chronic renal failure in hemodialysis, peritoneal dialysis, and predialysis patients. Benefits of epoetin therapy include reduced need for blood transfusions, the amelioration of anemic symptoms, and an improved quality of life.
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PMID:Epoetin: human recombinant erythropoietin. 268 Feb 41

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

Epoetin (recombinant human erythropoietin) is now a widely available though expensive treatment for the anaemia of chronic renal failure, and is effective in more than 95% of patients. Complications of epoetin in this context include hypertension in a third of cases, including hypertensive encephalopathy in a few, and thrombosis of shunts or vascular access devices. Fears that epoetin would cause progression of renal failure have not generally been confirmed, but hyperkalaemia may be a problem in the initial phase of treatment. Epoetin is up to twice as effective when administered subcutaneously rather than intravenously. Responding patients will normally do so within 3 months of starting epoetin. Failures to respond are usually due to iron deficiency or intercurrent disease. Other diseases associated with anaemia and an inappropriately low serum epoetin level include prematurity, the anaemia of cancer and rheumatoid arthritis. The baseline serum endogenous erythropoietin may provide a guide to response in some of these cases. Some encouraging results are being published. Situations where the serum erythropoietin levels are normal or elevated where epoetin has been employed include boosting of haematocrit presurgery as an adjunct to autologous blood donation, treatment of anaemic patients with myelodysplastic syndromes, and improvement of athletic performances.
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PMID:Controversies in selection of epoetin dosages. Issues and answers. 778 87

Many patients with solid tumours or haematological malignancies develop anaemia, and the use of chemotherapy aggravates this condition. Red blood cell transfusions are often necessary but are associated with many risks, including immunosuppressive effects that may increase the risk of tumour recurrence. Many clinical studies have shown that epoetin (recombinant human erythropoietin) therapy can ameliorate, or even prevent, the anaemia associated with chemotherapy and cancer (including solid tumours as well as multiple myeloma or lymphoma). Response, defined as a significant (>50%) reduction in the rate of transfusions and/or a significant (>2 g/dl) elevation of haemoglobin levels, is usually observed in about 60% of the patients, irrespective of the type of standard chemotherapy given. The decrease in transfusion requirements is the major objective of epoetin therapy, because they are costly, inconvenient and are associated with potential adverse effects. Epoetin therapy also brings about substantial improvements in various indices of quality of life that are proportional to changes in haemoglobin level. However, large dosages of epoetin are generally required and about 40% of patients do not respond even to very high dosages. A number of adverse effects of epoetin therapy have been observed in patients with renal failure. The most prominent include hypertension, headaches, seizures and thrombotic events. These complications can also occur in patients with renal failure who are not receiving epoetin. Their exact incidence has been assessed in placebo-controlled studies, which have demonstrated that there is no increased risk of thrombosis or seizure with epoetin. However, it is now generally accepted that 10 to 20% of haemodialysis patients will experience an elevation of blood pressure because of epoetin and there is no doubt that a rapid elevation of blood pressure may cause generalised seizures. In other settings, including anaemia associated with cancer, very few adverse effects have been attributed to epoetin. However, close monitoring of blood pressure should be implemented in patients with hypertension. There is no evidence that epoetin stimulates tumour growth. With the dosages of epoetin currently used, there is no evidence of stem cell competition, resulting in thrombocytopenia or neutropenia, or of stem cell exhaustion, producing secondary anaemia when treatment is stopped. Epoetin is a remarkably well tolerated drug that offers significant benefits in patients with cancer.
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PMID:A risk-benefit assessment of epoetin in the management of anaemia associated with cancer. 980 42

Decisions about epoetin (recombinant human erythropoetin) dosage and target haematocrit in dialysis patients have been determined largely by the high acquisition cost of epoetin, but are made with incomplete knowledge about which target haematocrit gives the optimum clinical benefit. Haematopoietic response to epoetin may be determined by pharmacodynamic factors such as rate and frequency of administration, as well as by individual patient characteristics such as ethnicity. Resistance to epoetin may be due to iron or vitamin deficiency, natural or exogenous inhibitors of erythropoiesis and bone marrow fibrosis. The high acquisition cost of epoetin must be considered along with a number of other factors that can influence the true cost of epoetin treatment. Hidden costs of epoetin treatment include administration costs, changes in other treatments, extra laboratory tests and adverse events. Administration costs and extra laboratory surveillance add little to overall cost. Depletion of iron stores, hypertension, increased blood coagulability and reduced dialyser efficiency resulting from epoetin treatment may all add a small additional component to the true cost. Severe complications with significant cost implications are rare. Amongst the various components of true cost, only the acquisition cost can definitely be reduced by low dosage treatment. Balanced against the true and potential costs of epoetin are a number of benefits which can result in potential savings. The need for blood transfusion is all but abolished, avoiding the cost of transfusion and its complications. Sensitisation against histocompatibility antigens is reduced by avoiding transfusion, and so the waiting time for cadaveric transplantation may be reduced. Rates of hospitalisation for all causes, especially those associated with anaemia, may be reduced by epoetin treatment. By improving well-being, epoetin may allow patients to be transferred to minimal-care units or home where dialysis can be performed much more cheaply. Amongst the various potential benefits of epoetin, the one with the greatest potential to save money for society is improved productivity. To date, productivity improvements with epoetin have been demonstrated only in small studies. If the acquisition costs of epoetin are reduced by low dosage therapy, these potential benefits can cover a large proportion of the total cost of epoetin. Epoetin undoubtedly improves quality of life and activity, but it is not clear which level of haematocrit gives optimum improvement.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Low-dosage epoetin in maintenance haemodialysis: costs and quality-of-life improvement. 1014 63

Epoetin (recombinant human erythropoietin) is an effective treatment for the anaemia of patients with chronic renal failure. It is well tolerated, and the risk of adverse effects that are caused by too rapid a correction of anaemia, for example hypertension, can be reduced in most cases by lower starting dosage regimens. Epoetin improves the quality of life of anaemic patients with end-stage renal disease (ESRD), and significant improvements in most parameters of the Kidney Disease Questionnaire, the Sickness Impact Profile and the Nottingham Health Profile have been reported by patients. However, acquisition costs of epoetin are high, thereby adding a considerable cost to ESRD therapy despite a reduction in blood transfusion requirements. Notwithstanding, although cost-effectiveness studies have indicated that epoetin is associated with higher costs of therapy, cost-benefit analysis indicates that these costs can be reduced markedly with low-dose regimens and may be completely recovered if patients regain employment.
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PMID:Epoetin: a pharmacoeconomic review of its use in chronic renal failure and its effects on quality of life. 1014 87

Anaemia commonly occurs in cancer patients receiving chemotherapy, often necessitating blood transfusion. This multicentre study was designed to evaluate the efficacy and safety of epoetin alpha in preventing the decline in haemoglobin (Hb) level, and to determine whether the transfusion requirement could be reduced, in patients receiving 4-6 cycles of primarily platinum-based combination cyclic chemotherapy for small cell lung cancer (SCLC). A total of 130 non-anaemic SCLC patients were randomized to receive no additional treatment (n = 44), epoetin alpha 150 IU kg(-1) subcutaneously (s.c.) three times a week (n = 42) or 300 IU kg(-1) s.c. three times a week (n = 44). Reductions in epoetin alpha dosage were made during the study if Hb level increased to >15 g dl(-1). The mean weekly dosage was 335 and 612 IU kg(-1), respectively, in the two active treatment groups. Significantly fewer (P < 0.05) epoetin alpha-treated patients experienced anaemia (Hb < 10 g dl(-1)) during the course of chemotherapy (300 IU kg(-1), 39%; 150 IU kg(-1), 48%; untreated, 66%). This was reflected in the significantly lower number of treated patients transfused [300 IU kg(-1), 20% (P< 0.001); 150 IU kg(-1), 45% (P< 0.05); untreated, 59%]. Epoetin alpha was well-tolerated, and there was no evidence of sustained, clinically significant, hypertension. In summary, epoetin alpha is effective and well-tolerated in maintaining Hb level and reducing transfusion requirement in patients undergoing cyclic chemotherapy for SCLC.
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PMID:Epoetin alpha prevents anaemia and reduces transfusion requirements in patients undergoing primarily platinum-based chemotherapy for small cell lung cancer. 1040 44

Epoetin treatment of renal anemia has been practiced in Slovenia since 1988. More than 90% of hemodialysis patients and 83% of peritoneal dialysis patients have been treated with epoetin. Epoetin has also been available for patients with renal anemia in the pre-dialysis period and for those with a failing kidney allograft. Although epoetin treatment did not accelerate the worsening of native kidney function or allograft function, intensified antihypertensive treatment was required in kidney graft recipients. In patients on peritoneal dialysis, hypervolemia had a greater effect on hypertension than did epoetin treatment. Epoetin resistance was connected with C-reactive peptide cryptorchidism, intact parathyroid hormone, and treatment with angiotensin-converting enzyme inhibitors. In hemodialysis patients, lower doses of epoetin were required for patients receiving low molecular heparin and those with lower iPTH. Epoetin alpha, epoetin beta and epoetin omega seemed to be effective and safe in the treatment of renal anemia. In the past 2 years, epoetins were administered to hemodialysis patients only intravenously.
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PMID:Our experience with epoetins in treating renal anemia. 1596 88

(1) Current treatments for anaemia in patients receiving cancer chemotherapy include blood transfusion and epoetin alfa and beta. These epoetins correct anaemia in 40% to 65% of patients and reduce the number of patients who require transfusions during the second and third months of treatment by 12-35% in absolute terms. (2) Darbepoetin alfa is slightly more glycosylated than epoetin alfa and beta. It is no more effective than these two drugs in chronic renal failure. Darbepoetin alfa is now approved for the treatment of anaemia in patients who are receiving chemotherapy for non myeloid malignancies. (3) Two placebo-controlled dose-finding studies and two placebo-controlled trials involving nearly 1000 patients in total have shown that darbepoetin alfa decreases the number of transfused patients by 17-25% in absolute terms, and that it probably reduces fatigue. However, one-quarter of patients receiving darbepoetin were nonetheless transfused. (4) In the absence of reliable comparisons, there is no firm evidence that darbepoetin alfa is more effective than other epoetins. (5) According to relatively imprecise company reports, darbepoetin alfa increased the risk of thromboembolic events during clinical trials (6% versus 3%), including pulmonary embolism (1.3% versus 0%); the company also states that darbepoetin alfa does not increase the risk of arterial hypertension, a classical effect of epoetin that is mentioned in the summary of product characteristics (SPC). Placebo-controlled trials and dose-finding studies show no impact on the outcome of cancer, but follow-up is limited and a negative effect cannot be ruled out. The company states that no cases of erythroblastopenia have occurred among more than 70 000 treated patients. (6) According to the SPC, darbepoetin alfa can be given once a week. However, the optimal epoetin dosing schedule is unknown. Epoetin therapy takes several weeks to correct anaemia, whereas transfusion is immediately effective. (7) In practice, darbepoetin alfa seems a little easier to administer than epoetin alfa or beta, but the advantages and disadvantages of these drugs as compared with blood transfusion are not entirely clear.
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PMID:Darbepoetin alfa: new indication/new dosage. No proven advantage in chemotherapy-induced anaemia. 1628 72

Anaemia is a frequent complication in cancer patients and may be multifactorial in origin. Treatment with recombinant human erythropoietin (rHuEPO) is an alternative to red blood cell transfusion. The evidence from clinical trials has established that patients with chemotherapy-induced anaemia with a haemoglobin concentration below 10 g/dl benefit from epoetin therapy. The native glycoprotein hormone consists of 165 amino acids with three N-glycosylation and one O-glycosylation sites. Epoetin and darbepoetin bind to the EPO receptor to induce intracellular signalling by the same intracellular molecules as native EPO. There are some differences in the glycosylation pattern which lead to variations in the pharmacokinetics and pharmacodynamics profiles. Pharmacokinetic and therapeutic studies have examined the use of rHuEPO administered intravenously and subcutaneously and there is accumulating evidence that the latter route has several advantages in cancer patients. After subcutaneous administration, the bioavailability of epoetin is about 20-30% and has a plasma half-life of >24 h. Darbepoetin has a longer half-life after subcutaneous administration of 48 h. The general recommendations are based on evidence from trials in which epoetin was administered 150 U/kg thrice weekly. The recommended initial dose for darbepoetin alpha is 2.25 mug/kg per week. The most serious adverse effects are hypertension, bleeding and increased risk of thrombotic complications. Caution is advised when used in patients who are at high risk for thromboembolic events. In the management of anaemic cancer patients, physicians should closely follow the National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO)/American Society of Hematology (ASH) guidelines.
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PMID:Erythropoietin pharmacology. 1805 26


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