ibuprofen and lisinopril

Pharmacodynamic interaction. Ibuprofen and other NSAIDs inhibit renal prostaglandin synthesis, which can reduce renal blood flow and glomerular filtration rate, particularly in patients with volume depletion or pre-existing renal impairment. This antagonises the antihypertensive and renoprotective effects of lisinopril, an ACE inhibitor. Additionally, both drugs can increase serum potassium, leading to a risk of hyperkalaemia.

Co-administration can result in reduced antihypertensive efficacy, increased blood pressure, and a decline in renal function. The risk of acute kidney injury and hyperkalaemia is highest in patients who are elderly, volume-depleted, or receiving diuretic therapy. In some cases, the interaction may contribute to the development of worsening renal failure or life-threatening hyperkalaemia.

Avoid routine co-prescription, especially in patients at increased risk. If unavoidable, use the lowest effective dose of ibuprofen for the shortest duration. Monitor blood pressure and serum creatinine, and potassium at baseline and within 1 to 2 weeks after starting or changing therapy. Consider alternative analgesics such as paracetamol or opioids, which have less effect on renal function and blood pressure.

This interaction is well established and documented in multiple clinical guidelines and drug interaction databases. The adverse effects on renal function and blood pressure have been demonstrated in observational studies and clinical trials. Regional guidance varies on whether combination is absolutely contraindicated or requires caution.