Iron supplementation/therapy adverse effects

Although EPO deficiency is the primary cause of CKD anemia, iron deficiency is often present, and it is essential to assess and monitor the CKD patient s iron status (NKF-K/DOQI guidelines). Iron stores in patients with CKD should be maintained so that transferrin saturation (TSAT) is greater than 20% and serum ferritin is greater than 100 ng/mL (100 mcg/L or 225 pmol/L). If iron stores are not maintained appropriately, epoetin or darbepoetin will not be effective, and most CKD patients will require iron supplementation. Oral iron therapy can be used, but it is often ineffective, particularly in CKD patients on dialysis. Therefore, intravenous iron therapy is used extensively in these patients. Details of the pharmacology, pharmacokinetics, adverse effects, interactions, dose, and administration of erythropoietin and iron products have been discussed previously. 

Iron-deficiency anemia in chronic PN patients may be due to underlying clinical conditions and the lack of iron supplementation in PN. Parenteral iron therapy becomes necessary in iron-deficient patients who cannot absorb or tolerate oral iron. Parenteral iron should be used with caution owing to infusion-related adverse effects. A test dose of 25 mg of iron dextran should be administered first, and the patient should be monitored for adverse effects for at least 60 minutes. Intravenous iron dextran then may be added to lipid-free PN at a daily dose of 100 mg until the total iron dose is given. Iron dextran is not compatible with intravenous lipid emulsions at therapeutic doses and can cause oiling out of the emulsion. Other parenteral iron formulations (e.g., iron sucrose and ferric gluconate) have not been evaluated for compounding in PN and should not be added to PN formulations. 

Most patients tolerate EPO therapy well. Iron deficiency can occur in patients treated with EPO and close monitoring of iron levels is necessary. Oral iron supplementation should be given if transferrin saturation drops to 20% or the serum ferritin level drops below 100 ng/mL. Some patients develop functional iron deficiency, in which the iron stores are normal, but the supply of iron to the erythroid marrow is less than that necessary to support the demand for RBC production. Therefore many practitioners routinely supplement EPO therapy with oral iron therapy. The hypertension commonly seen in end-stage renal disease patients on EPO is far less common in AIDS patients. More common toxicities of EPO administration include nausea, headache, fever, bone pain, and fatigue. Other adverse effects to monitor include seizures, thrombotic events, and allergic reactions such as rash or local reactions at the injection site. 

Cough In 5-20% of patients, ACE inhibitors induce a dry cough it usually is not dose-related, occurs more frequently in women than men, usually develops between 1 week and 6 months after initiation of therapy, and sometimes requires cessation of therapy. This adverse effect may be mediated by bradykinin, substance P, and/or prostaglandins. Thromboxane antagonism, aspirin, and iron supplementation reduce cough induced by ACE inhibitors. Once ACE inhibitors are stopped, the cough disappears, usually within 4 days. 

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See also in sourсe #XX -- [ , ]

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