What is the initial management for a newly diagnosed iron deficiency anemia in an adult male?

Initial Management of Iron Deficiency Anemia in Adult Males

In an adult male with newly diagnosed iron deficiency anemia, immediately initiate oral iron replacement therapy while simultaneously pursuing urgent gastrointestinal investigation with bidirectional endoscopy (gastroscopy and colonoscopy), as approximately one-third of men harbor significant GI pathology including malignancy. 1

Immediate Actions

Confirm the Diagnosis

• Verify iron deficiency with serum ferritin (the single most useful marker), though transferrin saturation can help if false-normal ferritin is suspected due to inflammation 1
• A hemoglobin rise ≥10 g/L within 2 weeks of starting iron therapy confirms absolute iron deficiency, even if initial iron studies were equivocal 1, 2

Start Iron Replacement Immediately

• Begin ferrous sulfate, fumarate, or gluconate one tablet daily (typically 325 mg ferrous sulfate = 65 mg elemental iron) 1, 2
• Do not defer iron therapy while awaiting investigations unless colonoscopy is imminent 1
• If gastrointestinal side effects occur, reduce to one tablet every other day rather than stopping—this maintains efficacy while improving tolerability 1, 2
• Monitor hemoglobin at 2-4 weeks; continue treatment for approximately 3 months after hemoglobin normalizes to replenish bone marrow iron stores 1

Mandatory Urgent Investigation

Why Investigation is Critical in Males

• GI pathologies including cancer cause IDA in approximately one-third of men, making urgent investigation essential 1, 3
• The risk of malignancy necessitates fast-track referral and evaluation 1

Initial Workup

• Detailed history focusing on: chronic blood loss (nosebleeds, GI bleeding), NSAID use, PPI therapy, dietary intake, previous GI surgery, family history of GI disease, and symptoms suggesting celiac disease 1
• Urinalysis or urine microscopy to exclude renal tract bleeding 1
• Celiac disease screening with serologic testing (found in 3-5% of IDA cases) 1

First-Line GI Investigation

• Gastroscopy and colonoscopy should be the first-line investigations in men with newly diagnosed IDA 1
• Perform small bowel biopsy during gastroscopy if celiac serology wasn't done 1
• If colonoscopy is not suitable, CT colonography is a reasonable alternative 1

If Initial Endoscopy is Negative

Further Investigation Criteria

• Pursue small bowel and renal tract investigation if there is inadequate response to iron therapy or recurrent IDA after negative bidirectional endoscopy 1
• Capsule endoscopy is the preferred test for examining the small bowel, as it is highly sensitive for mucosal lesions 1
• CT/MR enterography may be considered if capsule endoscopy is unsuitable, particularly for inflammatory or neoplastic disease 1

When to Stop Further Investigation

• After negative capsule endoscopy of acceptable quality, further GI investigation is only needed if ongoing IDA persists despite iron replacement 1

Long-Term Management

Monitoring for Recurrence

• Hemoglobin levels normalize with iron therapy in most cases, but IDA recurs in a minority on long-term follow-up 1
• Long-term iron replacement may be appropriate when the cause is unknown or irreversible 1

Alternative Iron Therapy

• Consider parenteral (intravenous) iron if oral preparations are not tolerated, malabsorption is present, or there is inadequate response 1
• Limited red blood cell transfusion may occasionally be required for symptomatic anemia, but iron replacement is still necessary post-transfusion 1

Critical Pitfalls to Avoid

• Never assume dietary insufficiency alone in adult males—this population requires GI investigation regardless of dietary history 3, 4
• Do not delay investigation waiting for iron therapy response—malignancy must be excluded urgently 1
• Avoid stopping iron therapy due to mild GI side effects—reduce frequency to every other day instead 1, 2
• Do not overlook celiac disease screening—it accounts for 3-5% of IDA cases and is easily missed 1