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 (interstitial lung disease/ILD)

I.b

Pneumonitis (ILD), acute and/or severe (may cause ARDS)

I.c

Eosinophilic pneumonia (pulmonary infiltrates and eosinophilia)

I.e

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

I.m

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

I.o

Pulmonary alveolar proteinosis (PAP)

I.r

Pulmonary nodulosis

I.z

Progression, acceleration or exacerbation of preexisting ILD/fibrosis

I.aa

An area or areas of consolidation

XLIII - Airway involvement

XLIII.ab

Cough (lone)

XLV - Pleural and/or pericardial involvement

XLV.m

Pleuropericarditis - Pleuropericardial effusion (ANA unknown or negative)

XLVI - Pulmonary vasculopathy

XLVI.b

Pulmonary arterial hypertension

XLIX - Systemic/Distant conditions, syndromes and reactions

XLIX.a

DRES syndrome - DRESS-like reaction

XLIX.d

Lupus - Lupus syndrome (see also Vd)

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

LVII.a

BAL: An excess proportion of lymphocytes

LVIII - Pathology

LVIII.a

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

LVIII.d

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

LVIII.o

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

LVIII.q

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

LIX - Infections & related conditions

LIX.g

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