Study of the Effects of High-dose N-acetylcysteine (NAC) in Idiopathic Pulmonary Fibrosis (IPF)

Inclusion Criteria:

• Diagnosis of IPF according to the International Consensus Statement

• Bronchoalveolar lavage (BAL) showing no features to support an alternative diagnosis.

• Patients in whom it was possible to determine single breath DLco.

• Patients with newly or previously diagnosed IPF, in whom it was clinically justifiedto use the standardised regimen azathioprine plus prednisone

Exclusion Criteria:

• Known intolerance to N-Acetylcysteine.

• Patients with respiratory infections at study entry should be excluded until theinfections have been treated successfully (VC and Dlco comparable with the valuesbefore the infection).

• Patients with pre-existing disease that interferes with the evaluation of IPF:extensive old TBC lesions, significant bronchiectasis, moderate or severe COPD.

• Patients with malignancy in the last 5 years. If the patient had a malignancy in thepast and is free of malignancy for more than five years, the patient is regarded ashealed.

• Patients with heart failure.

• Patients with hepatic function abnormalities contraindicating the use of azathioprine (i.e. clinically significant abnormalities of PTT and/or GGT).

• Patients with a renal clearance < 10ml/min and/or hematuria and/or proteinuria ofcollagen vascular disease origin. A renal clearance is only performed in the presenceof an abnormal serum creatinine and/or serum urea level.

• Patients who are artificially ventilated.

• Prednisone at a dose > 0.5 mg/kg/day (or other glucocorticoids such as triamcinolone,dexamethasone or methylprednisolone at an equivalent dose) or azathioprine at a dose > 2 mg/kg/day during the last month prior to inclusion.

• Use of other immunosuppressives (such as cyclophosphamide and colchicine) is notallowed in the last month and for the duration of the trial.

• Any form of anticancer therapy or methotrexate are not allowed when used for more than 1 week in the past and for the duration of the trial.

• Amiodarone or nitrofurantoin are not allowed in the last 5 years, when used for morethan 1 week in the past and for the duration of the trial.

• Allopurinol, oxypurinol, thiopurinol, anti-oxidants (e.g. vitamin E) or glutathionesupplements are not allowed in the last month and during the trial.

• The use of interferon or other antifibrotics (e.g. pirfenidone) is not allowed in thepast and during the study.

• The use of NAC therapy at a dosage of more than 600 mg/day is not allowed in the last 3 years for a total period of more than 3 months.

• Patients suffering or having suffered from documented active ulcer within the last 3years.

• Patients in whom the standardised treatment regimen is contraindicated or notjustified.

• Pregnancy.

• Known or suspected drug or alcohol abuse.

• Patients on other investigational compounds or participating in clinical trials oninvestigational compounds within the last 3 months.

• Patients expected to be non-compliant in taking the medication.