Epoetin Question

[pagandeva2000]

I am told that patients taking this medication have to be monitored for severe elevation of blood pressure. I am trying to understand how this happens. I have not administered this medication myself, but but I was told that there is a policy in my clinic (one that I, of course, cannot find) that says that after administering this medication, the client must wait for 1/2 hour for nurse monitoring. My drug guide doesn't say anything about this, but speaks of hypertensive encephalopathy/hypertension. What is the reason of this increase in blood pressure?

Thanks!

[NRSKarenRN, BSN, RN]

from prescribing info:

because of the length of time required for erythropoiesis — several days for erythroid progenitors to mature and be released into the circulation — a clinically significant increase in hematocrit is usually not observed in less than 2 weeks and may require up to 6 weeks in some patients.

chronic renal failure patients

hypertension: patients with uncontrolled hypertension should not be treated with epogen®; blood pressure should be controlled adequately before initiation of therapy. although there do not appear to

be any direct pressor effects of epogen®, blood pressure may rise during epogen® therapy. during the early phase of treatment when the hematocrit is increasing, approximately 25% of patients on

dialysis may require initiation of, or increases in, antihypertensive therapy.

hypertensive encephalopathy and seizures have been observed in patients with crf treated with epogen®. special care should be taken to closely monitor and aggressively control blood pressure in patients

treated with epogen®. patients should be advised as to the importance of compliance with antihypertensive therapy and dietary restrictions. if blood pressure is difficult to control by initiation of appropriate measures, the hemoglobin may be reduced by decreasing or withholding the dose of

epogen®. a clinically significant decrease in hemoglobin may not be observed for several weeks.

it is recommended that the dose of epogen® be decreased if the hemoglobin increase exceeds 1 g/dl in any 2-week period, because of the possible association of excessive rate of rise of hemoglobin with an exacerbation of hypertension.

in crf patients on hemodialysis with clinically evident ischemic heart

disease or congestive heart failure, the dose of epogen® should be carefully adjusted to achieve and maintain hemoglobin levels between 10-12 g/dl ...

seizures: seizures have occurred in patients with crf participating in epogen® clinical trials. in adult patients on dialysis, there was a higher incidence of seizures during the first 90 days of therapy

(occurring in approximately 2.5% of patients) as compared with later timepoints. given the potential for an increased risk of seizures during the first 90 days of therapy, blood pressure and the presence of premonitory neurologic symptoms should be monitored closely. patients should

be cautioned to avoid potentially hazardous activities such as driving or operating heavy machinery during this period....

click here to download the pdf version of prescribing information.

[GLORIAmunchkin72]

"...The incidence of hypertension associated with Epoetin is not associated with either the dose of Epoetin or whether a normal Hct is achieved.80,129 The hypertensive response is not observed in anemic patients without renal disease who are treated with Epoetin.124 Therefore, the cause of the Epoetin associated clinical hypertension remains unresoved to date. New onset or worsening hypertension in association with Epoetin therapy is thought to be related to an increase in vascular wall reactivity, along with hemodynamic changes related to an increasing red blood cell mass..."

http://www.kidney.org/professionals/Kdoqi/guidelines_updates/doqiupan_vii.html

[bluefabian]

Reading all these clinical research and reports really make me wonder if some of them are valid because my experience tells otherwise. Working with lots of Chronic renal failure patient, I am more concerned by HPT caused by fluid overload rather than EPO related (of which there are no consensus about this). Why? Because I know it has a much, much faster effect in contributing to stroke, edema, respiratory problems, heart failure...

RBC production depends on many factors - Iron stores - both immediate and storage (Ferritin and transferrin), iron supply (from injection or oral) and in some ways the % of matured cells. I found out that even with multiple EPO injection per week, some of these patients still exhibiting low Hb levels - 7-10 g/dl. In fact, achieving for target Hb levels close to normal (people) values is a bit unrealistic. Clearly here, there is a link between stimulating hormone and supply. Plus, we are not even taking into count minor blood loss during dialysis.

There are two types of EPO administration. IV and SC, the later with a faster half life (3-4 hours I think) while the later a few days. Maybe we should take this into consideration too?