Allopurinol: Sorrow to the marrow

Area of Science:

• Pharmacology
• Hematology
• Toxicology

Background:

• Allopurinol is a xanthine oxidase inhibitor commonly prescribed for chronic gout management.
• It functions by inhibiting purine metabolism to reduce uric acid levels.
• The drug is generally well-tolerated with a favorable safety profile.

Observation:

• A middle-aged hypertensive female on allopurinol for seven months presented with generalized weakness and exertional dyspnea.
• Investigations revealed pancytopenia, including severe anemia and thrombocytopenia, with mild hepatosplenomegaly and renal disease.
• Other potential causes like nutritional deficiencies, hemolysis, and infections were excluded.

Findings:

• The patient developed hypo/aplastic anemia, likely induced by allopurinol.
• Despite initial response to treatment including blood transfusions, steroids, and antibiotics, she experienced convulsions, anuria, and succumbed to leukopenic sepsis.
• This case presents a rare instance of fatal aplastic anemia attributed to allopurinol.

Implications:

• This case underscores the potential for allopurinol to cause severe hematological adverse events, including aplastic anemia.
• It emphasizes the critical need for vigilant monitoring of patients receiving allopurinol, even when generally considered safe.
• Healthcare providers should be aware of this rare but serious side effect for timely diagnosis and intervention.