From the FDA Drug Label
An immune mediated hemolytic anemia has been observed in patients receiving cephalosporin class antibacterials including ceftriaxone Severe cases of hemolytic anemia, including fatalities, have been reported during treatment in both adults and children. If a patient develops anemia while on ceftriaxone, the diagnosis of a cephalosporin associated anemia should be considered and ceftriaxone stopped until the etiology is determined.
The patient's deterioration after hospitalization, characterized by hemolytic anemia (indicated by a drop in hemoglobin to 6.3 g/dL), is most likely to be revealed by Coombs testing or Glucose-6-phosphate dehydrogenase level. However, given the information provided in the drug label, the most relevant test to reveal the cause of this patient's deterioration is A. Coombs testing, as it can help diagnose an immune-mediated hemolytic anemia, which is a known adverse reaction associated with ceftriaxone use 1.
From the Research
The most likely test to reveal the cause of this patient's deterioration after hospitalization is glucose-6-phosphate dehydrogenase (G6PD) level testing. This 5-year-old girl is experiencing acute hemolytic anemia triggered by azithromycin, which is evident from her dramatically decreased hemoglobin (6.3 g/dL), elevated bilirubin (2.3 mg/dL), dark urine, and abdominal discomfort. G6PD deficiency is an X-linked recessive disorder that makes red blood cells vulnerable to oxidative stress from certain medications, including some antibiotics like azithromycin 2. When exposed to these triggers, patients with G6PD deficiency experience rapid destruction of red blood cells, leading to hemolytic anemia. The clinical presentation of acute hemolysis shortly after medication administration, combined with the laboratory findings of anemia and hyperbilirubinemia without significant liver enzyme elevation, strongly suggests G6PD deficiency as the underlying cause. Key points to consider in this case include:
- The patient's symptoms and laboratory results are consistent with acute hemolytic anemia
- G6PD deficiency is a common cause of acute hemolytic anemia, particularly in response to certain medications or infections 3
- The patient's recent administration of azithromycin, a medication that can trigger hemolysis in G6PD-deficient individuals, supports this diagnosis
- Management would include discontinuing the offending medication (azithromycin), providing supportive care, and potentially blood transfusion if the anemia is severe or symptomatic. It is essential to note that while other tests, such as Coombs testing or liver ultrasonography, may provide additional information, G6PD level testing is the most direct and relevant test to determine the cause of this patient's deterioration 4.