Can you review and interpret the CBC, differential, comprehensive metabolic panel, and amiodarone level for a 51‑year‑old female patient?

Laboratory Interpretation for 51-Year-Old Female on Amiodarone

This patient has normocytic anemia with marked red cell size variation (elevated RDW), mild lymphopenia, borderline thrombocytopenia, hypoalbuminemia, hyperbilirubinemia, elevated alkaline phosphatase, and critically subtherapeutic amiodarone levels—requiring immediate investigation for the anemia etiology, nutritional/hepatic assessment, and urgent amiodarone dose adjustment to prevent arrhythmia breakthrough.

Critical Findings Requiring Immediate Action

Subtherapeutic Amiodarone Level

• Amiodarone: 163 ng/mL (therapeutic range: 1000-2500 ng/mL) 1
• Desethylamiodarone: 186 ng/mL
• This patient is at high risk for arrhythmia breakthrough or sudden death with levels this low 1
• The FDA label explicitly warns that inadequate amiodarone levels can result in "arrhythmia breakthrough or exacerbation of arrhythmia, which may result in death" 1
• Action needed: Verify medication compliance immediately; if compliant, increase dose and recheck level in 1-2 weeks

Anemia with High RDW

Hemoglobin: 9.9 g/dL (low)

• RDW: 21.5% (markedly elevated; normal 12.6-15.6%)
• MCH: 24.8 pg (low) and MCHC: 28.3 g/dL (low)
• MCV is normal at 88 fL, but the extremely elevated RDW indicates a mixed population of red cells—suggesting either:
  • Combined iron and B12/folate deficiency
  • Ongoing hemolysis with reticulocytosis
  • Recent transfusion
  • Myelodysplastic syndrome

Immediate workup needed:

• Iron studies (ferritin, TIBC, serum iron, transferrin saturation)
• Vitamin B12 and folate levels
• Reticulocyte count
• Peripheral blood smear review
• Consider hemolysis labs if clinically indicated (LDH, haptoglobin, indirect bilirubin)

Hematologic Abnormalities

White Blood Cell Findings

• Absolute lymphopenia: 0.9 × 10³/μL (normal 1.2-3.8)
• Relative neutrophilia: 78% (normal 41-72%)
• Absolute neutrophil count is normal at 4.6, so this represents a stress response pattern rather than true neutrophilia
• Lymphopenia can be seen with chronic illness, malnutrition (note the hypoalbuminemia), or viral infections
• Amiodarone itself can cause neutrophil changes with inclusion bodies on electron microscopy but does not typically cause lymphopenia 2

Platelet Findings

• Platelets: 168 × 10³/μL (just below normal range of 169-368)
• Borderline thrombocytopenia—monitor trend
• Consider checking for consumptive processes if declining

Metabolic Panel Abnormalities

Hepatobiliary Concerns

• Total bilirubin: 1.7 mg/dL (elevated)
• Alkaline phosphatase: 161 IU/L (elevated; normal 39-117)
• AST: 40 IU/L (upper limit of normal)
• ALT: 20 IU/L (normal)

The FDA label notes that "approximately 54% of patients receiving amiodarone have baseline liver enzyme elevations" and that "acute, centrolobular confluent hepatocellular necrosis leading to hepatic coma, acute renal failure, and death has been associated with amiodarone" 1. However, this patient's pattern (elevated alkaline phosphatase with minimal transaminase elevation) suggests:

• Cholestatic process rather than hepatocellular injury
• Consider biliary obstruction, infiltrative liver disease, or bone source for alkaline phosphatase
• The elevated bilirubin with low albumin raises concern for chronic liver disease or malnutrition

Action: Right upper quadrant ultrasound to evaluate biliary tree; consider fractionating alkaline phosphatase if bone disease suspected

Nutritional/Protein Deficiency

• Albumin: 3.1 g/dL (low; normal 3.8-4.9)
• Total protein: 5.5 g/dL (low; normal 6.0-8.5)
• Calcium: 8.4 mg/dL (low; normal 8.7-10.2)—likely reflects hypoalbuminemia; calculate corrected calcium

This constellation suggests:

• Chronic malnutrition
• Chronic liver disease
• Protein-losing enteropathy or nephropathy (though urine protein not provided)
• Malabsorption

Electrolyte Abnormalities

• CO2: 42 mmol/L (elevated; normal 21-31)—indicates metabolic alkalosis or chronic respiratory acidosis with compensation
• Chloride: 94 mmol/L (low; normal 96-106)—consistent with metabolic alkalosis
• Glucose: 129 mg/dL (elevated)—check HbA1c for diabetes screening

Renal Function

• Creatinine: 0.61 mg/dL with eGFR >90 mL/min/1.73m²—normal kidney function
• BUN: 11 mg/dL—normal

Thyroid Function

• TSH: 3.23 μIU/mL (normal 0.45-4.50)—euthyroid
• Amiodarone commonly causes thyroid dysfunction 34, but this patient's TSH is currently normal
• Continue monitoring TSH every 3-6 months on amiodarone therapy

Integrated Clinical Assessment

This 51-year-old woman presents with a complex picture requiring systematic evaluation:

1. Most urgent: Subtherapeutic amiodarone levels placing her at risk for fatal arrhythmia
2. Second priority: Normocytic anemia with very high RDW suggesting mixed deficiency or bone marrow pathology
3. Third priority: Hypoalbuminemia and cholestatic liver pattern requiring imaging and nutritional assessment
4. Fourth priority: Metabolic alkalosis (elevated CO2, low chloride)—assess for diuretic use, vomiting, or contraction alkalosis

Recommended Immediate Actions

Within 24-48 hours:

• Verify amiodarone compliance; adjust dose if compliant
• Complete anemia workup (iron studies, B12, folate, reticulocyte count, peripheral smear)
• Right upper quadrant ultrasound
• Nutritional assessment and dietary history
• Review medication list for diuretics or other causes of alkalosis

Within 1-2 weeks:

• Recheck CBC to assess anemia trend
• Recheck CMP after addressing nutritional status
• Recheck amiodarone level after dose adjustment
• Consider gastroenterology referral if malabsorption suspected

The combination of subtherapeutic amiodarone, anemia, and hypoalbuminemia suggests either severe medication non-compliance, malabsorption, or a systemic illness affecting multiple organ systems 34.