[Interstitial pneumopathies during amiodarone treatment. Determination of serum amiodarone, typing of lymphocytes from bronchiolo-alveolar lavage].

We report 6 cases of diffuse interstitial pneumonia complicating therapy. The patients' study included the determination of amiodarone plasma level by high performance liquid chromatography (HPLC) and a study of lymphocyte subpopulations in alveolar lavage (wash cut). The mean cumulative dosage of amiodarone was 229 g; clinical symptoms were mainly weight loss, asthenia, dyspnea and dry cough. Bronchiolo-alveolar lavage fluids contained numerous lymphocytes, of which were T cells with a predominance of T8 lymphocytes. This is compatible with an immunoallergic mechanism as suggested in allergic alveolitis and in other drug induced pulmonary diseases. The determination of plasma amiodarone level performed after amiodarone withdrawal consistently showed a level inferior to the toxic one. These data confirm the lack of correlation between the pneumonitis outbreak and the amiodarone plasma level. Study of the red cell concentration of amiodarone and its major metabolites seems to be of greater interest.