Darbepoetin alfa

CLINICAL USE

Treatment of anaemia associated with chronic renal failure, and with non-haematological malignancies in adult cancer patients receiving chemotherapy

DOSE IN NORMAL RENAL FUNCTION

Renal failure: 0.45 micrograms/kg once a week; dose is adjusted by 25% every 4 weeks according to response; maintenance every 1–2 weeksPatients not on dialysis: 0.75 mcg every 2 weeks; maintenance may be every 1–4 weeksCancer: 2.25 mcg/kg once a week, or 6.75 mcg/kg every 3 weeks; adjust doses by 50% every 4 weeks according to response

PHARMACOKINETICS

Molecular weight :30 000–37 000

%Protein binding :No data

%Excreted unchanged in urine : No data

Volume of distribution (L/kg) :0.05

half-life – normal/ESRD (hrs) :21 (IV), 73 (SC)/Unchanged

DOSE IN RENAL IMPAIRMENT

GFR (mL/MIN)

20 to 50 : Dose as in normal renal function

10 to 20 : Dose as in normal renal function

<10 : Dose as in normal renal function

DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

CAPD :Not dialysed. Dose as in normal renal function

HD :Not dialysed. Dose as in normal renal function

HDF/high flux :Not dialysed. Dose as in normal renal function

CAV/VVHD :Not dialysed. Dose as in normal renal function

IMPORTANT DRUG INTERACTIONS

Potentially hazardous interactions with other drugsCiclosporin and tacrolimus: monitor ciclosporin and tacrolimus levels; since these drugs are bound to red blood cells there is a potential risk of a drug interaction as haemoglobin concentration increasesACE inhibitors and angiotensin- II antagonists: increased risk of hyperkalaemia

ADMINISTRATION

Reconstition

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Route

SC, IV

Rate of Administration

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Comments

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OTHER INFORMATION

To convert to darbepoetin from epoetin, divide total weekly epoetin dose by 200 although that may slightly overestimate the darbepoetin doseSame dose may be given either SC or IV – monitor responseUse with caution in patients with a history of epilepsy as convulsions have been reported in patients with CKDOnce a pre-filled pen has been removed from the fridge and brought to room temperature it must be used within 7 daysPre-treatment checks and appropriate correction/ treatment needed for iron, folate and B12 deficiency, infection, inflammation or aluminium toxicity to produce optimum response to therapyConcomitant iron therapy (200–300 mg elemental oral iron) needed daily. IV iron may be needed for patients with very low serum ferritin (<100 nanograms/mL)May increase heparin requirement during

HD :Reported association of pure red cell aplasia (PRCA) with epoetin therapy.This is a very rare condition; due to failed production of red blood cell precursors in the bone marrow, resulting in profound anaemia. Possibly due to an immune response to the protein backbone of R-HuEPO. Resulting antibodies render the patient unresponsive to the therapeutic effects of all epoetins and darbepoetin

See how to identify renal failure stages according to GFR calculation

See how to diagnose irreversible renal disease

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