Venlafaxine-associated interstitial pneumonitis.

A 55-year-old woman was hospitalized with a 7-month history of progressive dyspnea on exertion and hypoxia despite a normal echocardiogram. The onset of her symptoms correlated with a dosage increase of venlafaxine. A multichannel computed tomography scan showed ground-glass opacities, and an open lung biopsy revealed interstitial pneumonitis consistent with extrinsic allergic alveolitis. Venlafaxine was discontinued, and corticosteroid therapy was started; the patient's hypoxia improved and the infiltrates evident on chest radiographs were reduced. The patient continued to improve after discontinuing venlafaxine, and other potential etiologies for interstitial pneumonitis were excluded. Thus, venlafaxine may have triggered extrinsic allergic alveolitis in this patient.