OBJECTIVE We compared the long-term efficacy of the combination of colchicine and/or D-penicillamine with prednisone, in comparison to prednisone alone in patients with idiopathic pulmonary fibrosis (IPF). METHODS Nonrandomized prospective study in patients with IPF confirmed by biopsy specimen. METHODS National Institute of Respiratory Diseases, Mexico. METHODS Fifty-six IPF patients were included in this study. Patients received either colchicine/ prednisone (n=19), D-penicillamine/prednisone (n=11), D-penicillamine/colchicine/prednisone (n=11), or prednisone alone (n=15). Prednisone therapy was started at 1.0 mg/kg/d for 1 month followed by a biweekly taper to a maintenance dose of 15 mg/d. Colchicine was administered at a daily dose of 1.0 mg, and D-penicillamine was given at a daily dose of 600 mg. RESULTS Response to therapy was assessed by changes in lung function test results as measured by total and vital lung capacities, arterial blood gas analysis at rest breathing room air, and survival. No significant differences either in lung mechanics or in arterial gases were found in any group relative to the baseline measurement. Thirteen of the 56 patients died during the first 2 years, and 29 were dead at 5 years follow-up. Comparison of survival curves by Cox regression model showed no statistically significant difference among the four groups. Known side effects attributable to prednisone were more common and severe than those attributable to the other drugs. CONCLUSIONS Our results suggest that neither colchicine nor D-penicillamine modified the progressive course of prednisone-treated IPF, and that the search for new drugs is imperative.