Both chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) frequently lead to a chronic cough that negatively impacts the quality of life (QOL) for patients and those around them. This is a randomized, double-blind, placebo-controlled trial to determine whether interferon-alpha, delivered in low doses via orally dissolving lozenges given 3 times per day for 4 weeks, can reduce the frequency and severity of chronic cough in patients with COPD or IPF. Cough frequency will be assessed via 24-hour digital audio recordings made prior to entry, and at weeks 2 and 4 of treatment. Cough severity will be assessed via a 100-mm visual analog scale questionnaire completed by the subject prior to entry and then weekly during treatment. Subjects will also complete questionnaires regarding cough frequency, duration and intensity, QOL, dyspnea, and antitussive medication usage weekly during treatment. All questionnaires will be repeated weekly during a 4-week post-treatment observation period to assess durability of response.
