Occurs either through direct toxicity or because of an acute hypersensitivity

Drug-induced interstitial nephritis

Aetiology

• Common drugs include ampicillin, rifampicin, thiazide diuretics, NSAIDs and allopurinol

Clinical features

• Usually starts about 15 days after starting the drug
• Patients usually have a fever and occasionally a rash

Investigations

• Bloods: can show eosinophilia

Management

• With withdrawal of the drug most recover although there can be long lasting damage
• In around a third the there is no obvious cause

Analgesic nephropathy

Aetiology

• Said to be more common in women and usually in individuals taking multiple different kinds of analgesics over a long period

Pathophysiology

• Patients develop papillary necrosis in addition to the tubulointerstitial nephritis

Clinical features

• Patients usually develop anaemia and a range of non-specific symptoms e.g. headache
• Many develop a UTI