D70.2 Other drug-induced agranulocytosis

Name of the Condition

• Other drug-induced agranulocytosis

Summary

Other drug-induced agranulocytosis is a condition characterized by a severe reduction or absence of neutrophils, a type of white blood cell essential for fighting infections. This occurs as a direct result of exposure to certain medications, excluding those used for cancer chemotherapy. The condition increases susceptibility to bacterial and fungal infections and may resolve once the causative drug is discontinued.

Causes

Other drug-induced agranulocytosis is caused by the toxic effects of specific medications on bone marrow, where neutrophils are produced. These drugs suppress bone marrow function, leading to a decrease in neutrophil production. The exact mechanisms vary by drug but often involve immune-mediated destruction of neutrophil precursors or direct marrow toxicity.

Risk Factors

• Use of medications known to cause agranulocytosis (e.g., certain antibiotics, antithyroid drugs, or antipsychotics)
• High doses or prolonged use of the causative drug
• Pre-existing bone marrow disorders
• Advanced age
• Concurrent use of other myelosuppressive medications

Symptoms

• Fever and chills (signs of infection)
• Sore throat or mouth ulcers
• Skin infections or abscesses
• Respiratory infections (e.g., pneumonia)
• Fatigue or weakness
• Rapid or irregular heartbeat

Diagnosis

Diagnosis is confirmed through blood tests showing a severe decrease in neutrophil count. A detailed medication history is critical to identify the causative drug. Additional tests, such as bone marrow aspiration, may be performed to rule out other causes of neutropenia.

Treatment Options

Treatment involves discontinuing the causative drug immediately. Supportive care, including antibiotics for infections and growth factors to stimulate neutrophil production, may be necessary. In severe cases, hospitalization for monitoring and treatment of infections is required.

Prognosis and Follow-Up

Prognosis is generally good if the causative drug is stopped promptly and infections are treated effectively. Neutrophil counts typically recover within weeks to months after discontinuation of the drug. Follow-up blood tests monitor recovery and ensure no recurrence of neutropenia.

Complications

• Severe, life-threatening infections (e.g., sepsis)
• Prolonged neutropenia leading to delayed recovery
• Recurrence if the causative drug is reintroduced

Lifestyle & Prevention

• Avoid known causative medications when possible.
• Inform healthcare providers of any history of drug-induced agranulocytosis.
• Practice good hygiene to reduce infection risk during recovery.

When to Seek Professional Help

Seek immediate medical attention if you experience fever, chills, or signs of infection while taking medications associated with agranulocytosis. Discontinue the suspected drug and contact a healthcare provider promptly.

Tips for Medical Coders

Document the specific drug or class of drugs responsible for the agranulocytosis, as this is essential for accurate coding. Ensure the medical record supports the temporal relationship between drug exposure and the onset of neutropenia. Code D70.2 is appropriate when the agranulocytosis is drug-induced but not secondary to cancer chemotherapy.