Hydrochlorothiazide-associated pulmonary edema.

The findings in a patient who developed low-pressure pulmonary edema on two separate occasions immediately following the ingestion of a single triamterene-hydrochlorothiazide tablet (Dyazide) are presented. It is postulated that this was related to the hydrocholorothiazide component of the drug. Although 12 cases have been reported, the pathophysiology remains obscure. Mitogenic stimulation of the patient's lymphocytes to concanavalin A, phytohemagglutinin, and pokeweed mitogen was assessed. Blastogenic responses to Staphylococcus aureus antigen, triamterene, and hydrochlorothiazide were also assessed. No hypersensitivity response could be demonstrated to either triamterene or hydrochlorothiazide. The initially low white blood cell count, associated with hemoconcentration, increased in the first 24 h in the hospital. This observation is consistent with intrapulmonary sequestration of granulocytes causing pulmonary edema.