[ACE inhibitor-associated interstitial lung infiltrates]

A 60-year-old woman was prescribed Captopril, 37.5 mg daily, for severe left-ventricular dysfunction with associated mitral regurgitation. Left ventricular function improved markedly in the subsequent 6 months and the mean pulmonary capillary wedge pressure became normal. However, exertional dyspnoea unexpectedly did not improve but rather increased and she also developed severe dry cough.

The chest radiogram and computed tomography revealed multiple small interstitial infiltrates in both lungs without signs of congestion. Body plethysmography did not demonstrate any obstructive or restrictive ventilatory abnormalities.

When captopril was discontinued, the cough improved and the exertional dyspnoea quickly disappeared without any further treatment. All immunological tests, including those for antibodies against bird antigens and for antinuclear antibodies, were negative. The interstitial infiltrates had already markedly regressed 9 days after captopril had been discontinued and they had disappeared after 2 months.

This case indicates that angiotensin-converting enzyme inhibitors should be considered as a cause of interstitial pulmonary infiltrates associated with dyspnoea.