Seizures in Dialysis Patients Treated with Recombinant Erythropoietin. Review of the Literature and Guidelines for Prevention

Anemia is one of the major limitations to rehabilitation in patients with end-stage renal disease (ESRD). The efficacy of recombinant human erythropoietin (rHuEPO) in the treatment of renal anemia is well established. Nevertheless, rHuEPO therapy has been associated with serious untoward effects. There appears to be an increased risk of hypertension, not infrequently accompanied by hypertensive encephalopathy and seizures. The mechanism of hypertension remains uncertain. It is associated with an increase in blood viscosity, a reversal of hypoxic vasodilatation, and, possibly, a direct pressor effect of the hormone. Seizures, otherwise, may be the result of cerebral hypoperfusion and, finally, of a focal cerebral edema. The guidelines for rHuEPO treatment and prevention of associated convulsions are outlined. The possible convulsive risk induced by this treatment, even at low doses, particularly in patients with a previous history of seizures, is stressed.

Long-term treatment of anemia with recombinant human erythropoietin in familial amyloidosis TTR V30M

Familial amyloidosis or familial amyloid polyneuropathy (FAP) TTR V30M is a hereditary disease presented, in most cases, as a sensorimotor and autonomic neuropathy. Normocytic and normochromic anaemia was found in 24.8% of symptomatic FAP patients associated to lower serum erythropoietin (Epo) levels. Erythropoietin has been reported as efficient in anaemia correction in this disease. To evaluate the tolerance and efficacy of this treatment, a retrospective longitudinal study with 24 patients was undertaken. Patients were followed for at least 6 months. Haemoglobin, hematocrit, iron status, serum creatinine and urea and r-HuEPO doses were monitored, at 0, 3 months, 6 months and at the end of the follow-up. Long-term use of r-HuEPO proved to be efficient in the treatment of anaemia in familial amyloidosis TTR V30M and, despite the disease progression, no resistance cases to this treatment were observed. Positive side effects, like improvement on orthostatic hypotension symptoms and well-being sensation, contributing to confirm erythropoietin as a drug of choice to treat anaemia in amyloidosis TTR V30M.

The new rHuEPO alpha (epotin) in the management of anemia of end-stage renal disease in patients on maintenance hemodialysis

Recombinant human erythropoietin has proved to be effective to treat anemia of end-stage renal disease (ESRD). The aim of this study was to assess the efficacy and safety profile of Epotin, a rHuEPO produced in the Middle East. One hundred thirty patients with Hct </= 27%; Hb </= 9 g/dL maintained on hemodialysis thrice weekly from 19centers in eight countries in the Middle East were recruited into this 13-week study. Depleted iron stores (TSTAT <20% and/or Serum ferritin < 100 microg/dL) were replenished prior to initiation of Epotin therapy, which was delivered intravenously in a dose of 150 U/kg body weight/week in three equal doses postdialysis and titrated according to hemoglobin (Hb) and hematocrit (Hct) response. Efficacy was assessed in terms of Hb/Hct response. Epotin raised the mean Hb level from 7.7 (+/- 1.2) g/dL to 12.0 (+/- 1.7) g/dL and Hct from 22.7 (+/- 4.1) % to 36.2 (+/- 5.7) % by week 13. The increase started to show significance at week 3. Targeting an absolute increase in Hb of 2.5 g/dL (Hct 7.5%) over a 13-week period, the success rate was of <85.71%. Segregating patients into subgroups of men and women and chronic ESRD versus recent ESRD failed to reveal a significant differences in either the severity of the anemia or the response to Epotin. Side effects were similar to other erythropoietins; no dropouts were reported. In conclusion, Epotin is effective to treat anemia in patients on maintenance hemodialysis with an acceptable safety profile. No difference in response was observed between men and women, nor between patients with different levels of chronicity of ESRD.

Dialysate sodium delivery can alter chronic blood pressure management

Low dialysate sodium concentrations can reduce postdialysis thirst and serum sodium activity, but patients typically experience dialysis hypotension, fatigue, disequilibrium, and cramps. "High-sodium" hemodialysis minimizes dialysis disequilibrium but increases the serum sodium activity of most patients. Programmed "variable-sodium" dialysis can minimize dialysis discomfort but may also alter the sodium kinetics from those of "high-sodium" dialysis. We designed a cross-over study with random order assignment to determine whether a "variable-sodium" dialysis program could reduce the blood pressure of dialysis patients without increasing dialysis morbidity. Dialysis with a dialysate sodium of 140 mEq/L was compared with dialysis with a programmed exponential decrease of dialysate sodium from 155 mEq/L to 135 mEq/L. Dialysate sodium was then held constant at 135 mEq/L for the final half hour of dialysis. Eighteen patients completed the 7-month study, each receiving 3.5 months of experimental and 3.5 months of standard therapy. Programmed "variable-sodium" dialysis resulted in a reduction in antihypertensive drug use without alterations in predialysis blood pressure, interdialytic weight gain, ultrafiltration tolerance, or the frequency of symptomatic dialysis cramps or hypotension. Patients did, however, have lower postdialysis standing blood pressures and higher postdialysis target weights during programmed "variable-sodium" dialysis.

Androgen therapy for anaemia of chronic renal failure. Indications in the erythropoietin era

The high cost of recombinant human erythropoietin has led us to consider the existing indications for androgen treatment of anaemia in patients with chronic renal failure. In the present work, we have tried to identify those patients on haemodialysis for whom androgens could constitute a therapeutic alternative. The evolution of haemoglobin concentration was analysed in 84 patients (67 males and 17 females) treated with a cycle of nandrolone decanoate (200 mg per week given intramuscularly, for six months). In the total group of patients, haemoglobin rose from 69 g/L to 87 g/L (p < 0.01). The increment in haemoglobin was not related to sex, basal haemoglobin, primary renal disease, or dose of nandrolone decanoate corrected by body weight. However, we observed a relationship between this increment in haemoglobin and patient age. Haemoglobin increased by 8 g/L in patients younger than 46 years (n = 29), by 18 g/L in patients aged between 46 and 55 years (n = 28), and by 27 g/L in patients older than 55 years (n = 27) (p < 0.01 between groups). In the last group, haemoglobin concentration at the end of androgen treatment was 101 +/- 16 g/L. The haemoglobin level reached during androgen treatment was maintained for over a year after androgen withdrawal in 55% of the responder patients. A reversible rise in the serum concentration of triglycerides was the main side-effect observed. Nandrolone decanoate therapy was not associated with hepatotoxicity or an increase in blood pressure. Voice change and mild hirsutism were observed in most of the women receiving nandrolone decanoate, and these secondary effects constitute a real disadvantage to its use in females. In conclusion, our results showed that androgens are a useful alternative in the treatment of anaemia in male haemodialysis patients older than 55 years. Furthermore, the response obtained was similar to that observed with erythropoietin, but at a lower cost.

Effects of androgen therapy on prostatic markers in hemodialyzed patients

We have prospectively studied the evolution of serum levels of the prostatic-specific antigen and prostatic acid phosphatase in 14 male hemodialyzed patients, receiving a cycle of nandrolone decanoate (200 mg intramuscularly, once a week, for six months) as treatment for anemia. Androgen administration did not produce significant increases in serum concentrations of both tumor markers (basal: 0.9 +/- 0.5 and 0.7 +/- 0.3 ng/ml; at six months: 1.3 +/- 1.1 and 0.8 +/- 0.7 ng/ml respectively). Only one patient had a value of prostatic-specific antigen over the normal range: 4.2 ng/mol at the sixth month period, with a rapid decrease after the withdrawal of androgens. All the remaining values of both markers were within the normal range. In another six patients undergoing a prolonged treatment with androgens (between 9 to 24 months), the serum levels of prostatic-specific antigen and prostatic acid phosphatase were within the normal range in all of them. Nandrolone decanoate administration does not induce increases in prostate tumor markers when it is used as treatment for anemia in hemodialyzed patients.

[Erythropoietin and arterial hypertension in patients with chronic renal insufficiency]

The induction or the aggravation of a hypertension is a side effect of recombinant human erythropoietin therapy in 30% of dialysed patients. Clinical manifestations can be severe. Pathogenesis of erythropoietin-induced hypertension is ill known. Peripheral vascular changes were found in most studies. Recently, it was demonstrated that erythropoietin increased endothelin-1 release by endothelial cells. Ambulatory blood pressure recording seems to be the best method for evaluating the modification of blood pressure profile during the interdialytic period. Erythropoietin-induced hypertension is easily controlled by drugs, but also by low dose of erythropoietin. Subcutaneous administration of erythropoietin is an approach to avoid the induction of hypertension. Furthermore economical advantages of subcutaneous administration are proven.

Serotonin is involved in the pathogenesis of hypertension developing during erythropoietin treatment in uremic rats

The aim of this study was to investigate the mechanism of erythropoietin-induced hypertension in respect to its action on blood serotonergic system. The experiment was carried out on healthy rats and animals with experimental chronic renal failure. Erythropoietin (rHuEPO) injected into the healthy and uremic rats caused an increase in systolic blood pressure. This effect was completely abolished by ketanserin, an antagonist of 5-HT2 receptors. Concomitantly a rise in blood and platelet serotonin concentration was observed. It is concluded that serotonin may play a role in the development of hypertension caused by rHuEPO. Moreover, ketanserin may serve as a drug for pharmacological protection of rHuEPO-induced rise of blood pressure in uremia.