Acute Respiratory Toxicity and Hydrochlorothiazide

The product information documents for a number of hydrochlorothiazide-containing products have recently been updated. These products now contain a special warning regarding reports of acute respiratory toxicity.

Acute respiratory toxicity is considered a rare adverse effect associated with hydrochlorothiazide. It presents with pulmonary oedema which can occur within minutes to hours of the initial dose. Early symptoms can include dyspnoea, fever, hypotension, and pulmonary deterioration. Cases can be severe and include acute respiratory distress syndrome (ARDS). Patients who experience ARDS in association with hydrochlorothiazide should not take hydrochlorothiazide again.

Hydrochlorothiazide is a thiazide diuretic indicated for the treatment of hypertension and oedema associated with heart failure, hepatic cirrhosis, or nephrotic syndrome. It is available as a single-ingredient tablet and also in fixed-dose combination with ACE inhibitors, angiotensin II antagonists, or calcium channel blockers. While acute respiratory toxicity is rare, it is important to be aware of due to the relatively common use of hydrochlorothiazide and the potential severity of this adverse effect.