What psychiatric and antihypertensive drugs are most likely to cause Acute Interstitial Nephritis (AIN)?

From the Research

Acute interstitial nephritis (AIN) is most commonly caused by certain psychiatric and antihypertensive medications, with antibiotics, nonsteroidal anti-inflammatory agents, and proton pump inhibitors being the most frequently implicated classes of medications, as reported in the most recent study 1. Among psychiatric drugs, atypical antipsychotics like clozapine are known to cause AIN, as demonstrated in a case study where a patient developed clozapine-induced AIN, confirmed with kidney biopsy 2. For antihypertensive medications, diuretics, ACE inhibitors, and ARBs are also potential causes of AIN. These medications can trigger an immune-mediated hypersensitivity reaction in the kidneys, leading to inflammation of the renal interstitium. The reaction typically develops within days to weeks after starting the medication, though it can occasionally occur after longer periods of use. Symptoms include decreased urine output, elevated creatinine, fever, rash, and eosinophilia. Management involves prompt discontinuation of the offending drug, which often leads to recovery of renal function, though some patients may require corticosteroid treatment in severe cases, as supported by a study that found early corticosteroid treatment can decrease the inflammatory infiltrates of the kidney interstitium and prevent subsequent fibrosis 1. Healthcare providers should monitor renal function when starting these medications, especially in patients with pre-existing kidney disease or those taking multiple nephrotoxic drugs. Key points to consider include:

• The importance of prompt diagnosis and discontinuation of the offending drug to prevent further kidney injury
• The use of corticosteroids in the treatment of DI-AIN, especially when started promptly
• The need for kidney biopsy to confirm diagnosis, as the symptoms of DI-AIN are often nonspecific
• The potential for almost all drugs to produce DI-AIN, with antibiotics, nonsteroidal anti-inflammatory agents, and proton pump inhibitors being the most commonly implicated classes of medications 1.