Amantadine Effect on Peripheral Airways Abnormalities in Influenza

Abstract

Amantadine HCl administration has resulted in accelerated resolution of influenza A illness. Prolonged abnormalities in pulmonary function were described in uncomplicated influenza A. To study the effect of amantadine on these changes, young adults with documented natural influenza A with clear chest examinations and X rays were evaluated. Subjects received placebo or amantadine in random, double-blind fashion. Physiologic studies included maximal expiratory flow volume curves with air and HeO2 mixtures. Air flow rates were unchanged in all subjects throughout. Initially, both groups showed comparable decreases in mean HeO2 maximal expiratory flow rates. The amantadine group showed accelerated physiologic improvement; significant increase in HeO2 flow rates occurred within 7 days (P < 0.05). The rate of improvement in the HeO2 flow rates in the placebo group was not statistically significant. These studies confirm peripheral airways dysfunction after uncomplicated influenza A and suggest that amantadine is associated with accelerated resolution of this dysfunction.