* use of systemic steroids (oral or intravenous) at doses greater than 15 mg/day one month prior to randomisation. * severe or moderate myopathy that may associate a decrease of fvc. * severe or life-limiting chronic disease prior to covid19 infection, including severe asthma, cancer, clinical dementia, ipf, or uncontrolled ischemic cardiomyopathy. * treatment with pirfenidone or nintedanib prior to covid19 * concomitant treatment with significant interactions with pirfenidone (such as fluvoxamine). * participation in any other investigational trial throughout the study * active smoking. * relevant blood alterations in the analysis made during the screening period: * total bilirubin \> 2 uln * ast/sgot or alt/sgpt \> 2.5 uln * alkaline phosphatase \>3.0 uln * creatinine clearance \<40 ml/min, calculated by the cockcroft-gault formula * pregnancy or lactation * concomitant treatments that can cause severe digestive problems. * gastric surgery in the last 3 months or similar procedures that may increase gastric intolerance. * inability to complete required visits. * previous intolerance or allergy to pirfenidone or hypersensitivity to any of its excipients. * history of angioedema

* use of systemic steroids (oral or intravenous) at doses greater than 15 mg/day one month prior to randomisation. * severe or moderate myopathy that may associate a decrease of fvc. * severe or life-limiting chronic disease prior to covid19 infection, including severe asthma, cancer, clinical dementia, ipf, or uncontrolled ischemic cardiomyopathy. * treatment with pirfenidone or nintedanib prior to covid19 * concomitant treatment with significant interactions with pirfenidone (such as fluvoxamine). * participation in any other investigational trial throughout the study * active smoking. * relevant blood alterations in the analysis made during the screening period: * total bilirubin \> 2 uln * ast/sgot or alt/sgpt \> 2.5 uln * alkaline phosphatase \>3.0 uln * creatinine clearance \<40 ml/min, calculated by the cockcroft-gault formula * pregnancy or lactation * concomitant treatments that can cause severe digestive problems. * gastric surgery in the last 3 months or similar procedures that may increase gastric intolerance. * inability to complete required visits. * previous intolerance or allergy to pirfenidone or hypersensitivity to any of its excipients. * history of angioedema

- use of systemic steroids (oral or intravenous) at doses greater than 15 mg/day one month prior to randomisation. - severe or moderate myopathy that may associate a decrease of fvc. - severe or life-limiting chronic disease prior to covid19 infection, including severe asthma, cancer, clinical dementia, ipf, or uncontrolled ischemic cardiomyopathy. - treatment with pirfenidone or nintedanib prior to covid19 - concomitant treatment with significant interactions with pirfenidone (such as fluvoxamine). - participation in any other investigational trial throughout the study - active smoking. - relevant blood alterations in the analysis made during the screening period: - total bilirubin > 2 uln - ast/sgot or alt/sgpt > 2.5 uln - alkaline phosphatase >3.0 uln - creatinine clearance <40 ml/min, calculated by the cockcroft-gault formula - pregnancy or lactation - concomitant treatments that can cause severe digestive problems. - gastric surgery in the last 3 months or similar procedures that may increase gastric intolerance. - inability to complete required visits. - previous intolerance or allergy to pirfenidone or hypersensitivity to any of its excipients. - history of angioedema

- use of systemic steroids (oral or intravenous) at doses greater than 15 mg/day one month prior to randomisation. - severe or moderate myopathy that may associate a decrease of fvc. - severe or life-limiting chronic disease prior to covid19 infection, including severe asthma, cancer, clinical dementia, ipf, or uncontrolled ischemic cardiomyopathy. - treatment with pirfenidone or nintedanib prior to covid19 - concomitant treatment with significant interactions with pirfenidone (such as fluvoxamine). - participation in any other investigational trial throughout the study - active smoking. - relevant blood alterations in the analysis made during the screening period: - total bilirubin > 2 uln - ast/sgot or alt/sgpt > 2.5 uln - alkaline phosphatase >3.0 uln - creatinine clearance <40 ml/min, calculated by the cockcroft-gault formula - pregnancy or lactation - concomitant treatments that can cause severe digestive problems. - gastric surgery in the last 3 months or similar procedures that may increase gastric intolerance. - inability to complete required visits. - previous intolerance or allergy to pirfenidone or hypersensitivity to any of its excipients. - history of angioedema