How should mild anemia with hypoferritinemia be interpreted in a 46-year-old man with a history of hidradenitis suppurativa, taking cephalexin (Cefalexin) 500 mg daily?

From the Guidelines

The patient's lab results indicate iron deficiency anemia, and treatment should include oral iron supplementation to replenish iron stores and improve quality of life, as recommended by the most recent guidelines 1. The patient's hemoglobin of 13.6 g/dL is slightly below normal for adult males (normal range typically 14-18 g/dL), representing mild anemia. The iron studies confirm iron deficiency with a low serum iron level (44 μg/dL), normal total iron binding capacity (316 μg/dL), low transferrin saturation (14%, normal is typically 20-50%), and elevated unsaturated iron binding capacity (272 μg/dL).

Key Points to Consider:

• The patient's iron deficiency anemia is likely related to his underlying condition, and treatment should focus on replenishing iron stores and addressing the underlying cause of iron deficiency.
• The European Crohn's and Colitis Organization (ECCO) guidelines recommend intravenous iron as first-line treatment in patients with clinically active IBD, but oral iron may be used in patients with mild anemia, whose disease is clinically inactive, and who have not been previously intolerant to oral iron 1.
• The patient should be advised to take iron with vitamin C to enhance absorption and avoid taking it with calcium, dairy, coffee, or tea which can decrease absorption.
• Follow-up hemoglobin and iron studies should be conducted after 1-2 months of supplementation to monitor response to treatment.

Treatment Recommendations:

• Oral iron supplementation, typically ferrous sulfate 325 mg three times daily between meals for 3-6 months, to replenish iron stores.
• Investigate the underlying cause of iron deficiency, considering potential blood loss from his hydradenitis suppurativa or possible gastrointestinal sources.
• Monitor the patient's response to treatment and adjust as necessary to ensure improvement in hemoglobin levels and quality of life.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Interpretation of Lab Results

The patient's lab results show a hemoglobin level of 13.6, which is considered mild anemia. The iron studies reveal an iron level of 44, iron binding capacity of 316, transferrin saturation of 14, and unsaturated iron binding capacity of 272.

• The transferrin saturation (TSAT) is calculated as the ratio of iron to total iron binding capacity (TIBC), which in this case is 14% (44/316 x 100).
• According to 2, iron deficiency is diagnosed by a transferrin saturation less than 20%. Since the patient's TSAT is 14%, this indicates iron deficiency.
• The patient's unsaturated iron binding capacity (UIBC) is 272, which is elevated, further supporting the diagnosis of iron deficiency.
• The patient's iron level is 44, which is lower than normal, also indicating iron deficiency.

Diagnosis and Treatment

Based on the lab results, the patient has iron deficiency anemia.

• As stated in 3, the most efficient test for the diagnosis of iron deficiency is the serum ferritin, but in this case, the transferrin saturation and iron level are used to diagnose iron deficiency.
• According to 2, oral iron (ferrous sulfate 325 mg/d or on alternate days) is typically first-line therapy for iron deficiency anemia.
• The patient is currently taking cephalexin 500 mg daily, but there is no indication that this medication is contributing to the iron deficiency anemia.
• As mentioned in 4, identifying the underlying cause of iron deficiency is necessary to guide management of these patients. In this case, the cause of iron deficiency is not specified, but it may be related to the patient's past medical history of hydradenitis suppurativa or other underlying conditions.

Management

The patient's iron deficiency anemia should be managed with oral iron supplementation, as stated in 2 and 5.

• The patient should be monitored for symptoms of iron deficiency anemia, such as fatigue, and for adverse effects of iron supplementation, such as gastrointestinal side effects.
• As mentioned in 6, ferrous sulfate is a commonly prescribed oral iron supplement that has been shown to be effective in increasing hemoglobin concentration in patients with iron deficiency anemia.