Erythropoiesis-stimulating agents
Erythropoiesis-stimulating agents (ESAs) should be used in patients who have an Hb <11.0g/dl3, or higher if symptomatic, and who are iron replete. ESAs can be given as IV or subcutaneous injections. In practice, the IV route is reserved for use in haemodialysis patients. Six types of ESA are available. Epoetin alfa is only licensed for IV use in chronic renal failure. Epoetin alfa is given three times per week, as is epoetin beta, but this can be given weekly. Epoetin delta is given twice weekly. Darbepoetin alfa is given weekly or fortnightly, and methoxypolyethylene glycol-epoetin beta is given monthly. ESAs can cause hypertension and hyperkalaemia, so careful monitoring is required.

A dose of ESA, called a correction dose and calculated on the patient’s weight, should be given and Hb, U&E, and BP should be monitored fortnightly. The aim is for an increase in Hb of 2g/dL per month. Dose titrations of 25-30 per cent of the total dose should be made if the Hb rises too quickly or too slowly. Rises >2g/dL increase the risk of hypertension and hyperkalaemia. The dosage regimens of commonly used ESAs are given in Box 4.

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Once a target of 11-12g/dL is achieved, the patient should receive a maintenance dose of ESA. Monitoring should continue fortnightly until Hb levels are stable, after which, it should occur at a minimum of three-monthly intervals.5 Should ESA requirements increase during monitoring, or high doses be required to maintain a satisfactory Hb, another cause for anaemia should be excluded, such as GI blood loss. Acute and chronic infections also impair the effectiveness of ESAs and should be considered when treatment resistance is encountered.

ESA therapy is limited by the speed at which anaemia can be corrected. If the patient is severely anaemic or significantly symptomatic, a blood transfusion should be given. Large doses of a loop diuretic may be required to avoid fluid overload if the patient has inadequate residual renal function. In such cases, a dose equivalent to their usual diuretic dose should be given for every two units of blood.

Management of itching and pain
Itching is another problem patients often encounter and various measures can be used to alleviate this (see Box 5). Pain management in renal failure is challenging because of the problem of eliminating opiates and their metabolites. However, because pain is one of the most common debilitating symptoms, the adverse effects of analgesics should be weighed against the benefits of pain relief. The problem with the use of NSAIDS is that they can impair vital residual renal function and increase the risk of bleeding in the uraemic patient. If they are used, the starting dose should be given twice daily and at a low dose, combined with a proton pump inhibitor to help protect the gastric mucosa.3 Neuropathic pain is common and can be treated with amitriptyline 25mg once daily, gabapentin 100mg once or twice daily*, pregabalin 25mg once daily, or carbamazepine 100mg twice daily.

*Extreme caution is advised, in our experience gabapentin can be a very useful treatment, but must be used in low dose due to risk of accumulation in renal failure.

Traditional opiate analgesics accumulate in renal failure and can cause toxicity hours or days after a dose is given. Morphine metabolises to 3-OH-morphine and 6-OH morphine, both more pharmacologically active than the parent compound. These accumulate to a large extent in renal impairment. Morphine should be used at very low doses and with great caution, or avoided.