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The Drug-Induced Respiratory Disease Website and App

Leflunomide

The mere existence of the entity 'leflunomide pneumonitis' is disputed (PMID 26980577). Somes cases were receiving methotrexate concomitantly. The condition is rare if it at all exists outside Japan (PMID 26980577)

Frequency - Incidence

Incidence of respiratory adverse event(s) due to the specific drug as assessed by number of reported/published cases in the literature. Red digits in stars indicate: 0 = Very rare, questionable signal · 1 = < 10 cases · 2 = 10-50 cases · 3 = 50–100 cases · 4 = 100-200 cases · 5 = >200 cases

Evidence level/grade

Evidence level for respiratory adverse event(s) due to the specific drug as estimated using Hill’s (1965), Naranjo’s (1981), and Bégaud’s (1985) criteria applied to published cases. Blue digits in stars indicate: 0 = Questionable · 1 = Low · 2 = Moderate · 3 = Robust · 4 = Definite · 5 = Unquestionable, pathognomonic

I - Interstitial/parenchymal lung disease

I.a

Pneumonitis (ILD), acute and/or severe (may produce the ARDS pattern)
I.b

Pneumonitis (interstitial lung disease/ILD)
I.c

Eosinophilic pneumonia (pulmonary infiltrates and eosinophilia)
I.d

Organizing pneumonia pattern (an area or areas of consolidation on imaging)
I.l

Diffuse alveolar damage (DAD) (see alsoo under IIb and XVf)
I.n

Pulmonary alveolar proteinosis (PAP)
I.q

Pulmonary nodulosis
I.y

Progression, acceleration or exacerbation of preexisting ILD/fibrosis
I.z

An area or areas of consolidation

IV - Airway involvement

IV.d

Cough (lone)

V - Pleural and/or pericardial involvement

V.m

Pleuropericarditis - Pleuropericardial effusion (ANA unknown or negative)

VI - Pulmonary vasculopathy

VI.b

Pulmonary arterial hypertension

X - Systemic/Distant conditions, syndromes and reactions

X.a

DRES syndrome - DRESS-like reaction
X.d

Lupus - Lupus syndrome (see also Vd)

XV - Pathology

XV.a

Path: NSIP-cellular pattern (see also Ia, Ib)
XV.c

Path: Organizing pneumonia (OP/BOOP) pattern (see also Id)
XV.f

Path: Diffuse alveolar damage (DAD-pattern) (see also IL)
XV.i

Path: Pneumocyte atypia (reactive epithelial cells) (a.k.a. the "Napoleon Hat" sign)

XVII - Infections & related conditions

XVII.g

Tuberculosis (pulmonary, pulmonary, extrapulmonary or disseminated). Reactivation or de novo

XIX - Cytological, biochemical features of/in BAL, pleural fluid or FNA

XIX.a

BAL: An excess proportion of lymphocytes