Clinical use of evidence-based medicine--clinical questions: Acetylcysteine, a new treatment for an old foe?

This is a small, good quality, randomized controlled trial that shows a modest slowing in the deterioration of VC and DLco with the addition of high dose N-acetylcysteine to standard therapy in IPF. Overall the study should be interpreted with caution given its high drop out rate, which may have biased the results towards a more dramatic slowing of the disease progression. There were no differences in dyspnea score or functional status. There was no increase in the adverse events in the N-acetylcysteine group and the medication is inexpensive. Given only modest effects of N-acetylcysteine on VC and DLco, no change in functional scores, and the flaws of the study we would hesitate to use N-acetylcysteine as standard therapy in all patients with IPF.