What is drug-induced tubuluinterstitial nephritis?

➢Acute drug-induced TIN occurs as an adverse reaction to any one of an increasing number of drugs. ➢It is associated most frequently with : Penicillins (methicillin, ampicillin), Other antibiotics (rifampin), Diuretics (furosemide), Proton pump inhibitors (omeprazole), Nonsteroidal anti-inflammatory agents, Numerous other drugs (phenindione, cimetidine, immune checkpoint inhibitors). Morphology: ➢ The abnormalities in acute drug-induced nephritis are in the interstitium, which shows pronounced edema and infiltration by mononuclear cells, principally lymphocytes and macrophages ➢ Eosinophils and neutrophils may be present, often in large numbers. ➢ With some drugs (e.g., methicillin, thiazides,rifampin), T cell mediated reaction may give rise to interstitial nonnecrotizing granulomas with giant cells. ➢The glomeruli are normal except in some cases caused by nonsteroidal anti-inflammatory agents, in which the hypersensitivity reaction also leads to podocyte foot process effacement and the nephrotic syndrome