How to manage an 85-year-old patient with iron deficiency anemia, pre-diabetes, dyslipidemia, and stable CKD who is intolerant to iron tablets?

Management of Iron Deficiency Anemia with Oral Iron Intolerance in an 85-Year-Old with CKD

Switch to a liquid iron preparation as requested, starting with ferrous sulfate liquid or ferrous gluconate liquid at a lower dose (50-100 mg elemental iron daily), taken on an empty stomach, and if this remains intolerable, proceed directly to intravenous iron therapy rather than continuing to trial multiple oral formulations. 1

Iron Replacement Strategy

First-Line Approach: Liquid Oral Iron

• Trial a liquid iron preparation (ferrous sulfate or ferrous gluconate suspension) at 50-100 mg elemental iron once daily, taken in the fasting state 1
• Lower doses (50-100 mg daily) are as effective as traditional higher doses (200 mg twice daily) and significantly better tolerated, with lower rates of nausea 1
• Taking iron at bedtime may improve tolerance if daytime dosing causes symptoms 1
• Consider adding ascorbic acid 250-500 mg with the iron dose to enhance absorption, though evidence for effectiveness in IDA treatment is limited 1

Critical Monitoring Point

• Check hemoglobin after 2 weeks of therapy - failure to achieve at least a 10 g/L rise is strongly predictive of treatment failure (sensitivity 90.1%, specificity 79.3%) and should prompt immediate switch to parenteral iron 1
• The patient's hemoglobin is currently 106 g/L with iron normalized at 17, suggesting the previous oral iron partially worked before intolerance developed 1

When to Proceed to Intravenous Iron

Move to IV iron if:

• Liquid oral iron causes continued GI intolerance (nausea, vomiting) 1
• No hemoglobin rise ≥10 g/L after 2 weeks of adequate oral therapy 1
• Patient has CKD stage 3b (eGFR 38) with functional iron deficiency, where IV iron is more effective than oral 2, 3

IV Iron Selection for CKD Patients

For this patient with stable CKD (eGFR 38), intravenous iron is actually preferred over oral iron based on CKD guidelines, as oral iron absorption is impaired and less effective in CKD patients 1, 2, 3

Recommended IV iron options:

• Iron sucrose (Venofer): 200 mg per dose over 10-30 minutes, no test dose required, cost £102 per 1000 mg 1
• Ferric carboxymaltose (Ferinject): Up to 1000 mg single dose over 15 minutes, no test dose required, cost £154-217 per 1000 mg 1
• Avoid iron dextran due to higher anaphylaxis risk (0.6-0.7%) and requirement for test dose 1

Important Safety Considerations

• All IV iron requires resuscitation facilities immediately available 1
• The elevated ferritin (482) likely reflects inflammation/infection rather than iron overload, given the low serum iron (17) and anemia 1
• In CKD patients, functional iron deficiency is defined as transferrin saturation ≤20% with ferritin up to 200 ng/mL (non-dialysis CKD) 2, 3

Management of Comorbidities Affecting Iron Therapy

Pre-diabetes (HbA1c 47)

• Dietary counseling to reduce refined carbohydrates and increase fiber intake
• Monitor HbA1c every 3-6 months
• Weight optimization if applicable

Dyslipidemia (Triglycerides 2.1)

• Continue atorvastatin 40 mg
• Dietary modification: reduce simple sugars and alcohol, increase omega-3 fatty acids
• Triglyceride elevation may be related to pre-diabetes

Stable CKD (eGFR 38)

• The stable eGFR (38-41 over past year) indicates CKD stage 3b
• Continue current antihypertensive regimen (amlodipine, chlorthalidone, quinapril)
• Monitor eGFR and creatinine every 3-6 months 1

Follow-Up Protocol

After initiating iron therapy:

• Check hemoglobin at 2 weeks to assess response 1
• If responding, recheck hemoglobin monthly until normalized 1
• Once hemoglobin normalizes, continue iron for 3 months to replenish stores 1
• Monitor hemoglobin every 3 months for 1 year, then annually 1

Critical Pitfalls to Avoid

• Do not continue trialing multiple oral iron formulations if liquid iron fails - this delays effective treatment and the guidelines recommend moving to parenteral iron after intolerance to oral preparations 1
• Do not be falsely reassured by the elevated ferritin - this represents inflammation, not adequate iron stores, given the low serum iron and anemia 1
• Do not use iron polysaccharide - it is more expensive and no better tolerated than ionic iron salts 1
• Avoid taking iron with food, calcium supplements, or within 2 hours of other medications - this reduces absorption by up to 50% 1
• The patient's dysphagia (cuts tablets in half) makes liquid preparations particularly appropriate 1