What is a potential serious side effect of hydralazine hydrochloride that should be monitored for?

Agranulocytosis is a potentially serious side effect associated with hydralazine hydrochloride, a medication used primarily for managing hypertension. It is a condition characterized by a dangerously low level of neutrophils, a type of white blood cell essential for fighting off infections. The monitoring of blood counts during treatment is crucial because agranulocytosis can lead to increased susceptibility to infections, fever, and other complications if not identified and managed promptly.

Hydralazine is known to induce autoimmune reactions in some patients, which can lead to blood dyscrasias, including agranulocytosis. This underscores the importance of regular lab tests to ensure that the patient's blood cell counts remain within safe limits throughout the course of therapy.