Single-dose diclofenac in healthy volunteers can cause decrease in renal perfusion measured by functional magnetic resonance imaging.

Abstract

We investigated changes of renal perfusion after topical and oral diclofenac administration in healthy volunteers using functional magnetic resonance imaging (MRI) with arterial spin labelling (ASL). Twenty-four healthy human participants (21-51years) underwent 1.5T MRI before and 1h after a single oral dose of diclofenac (50mg). Twelve of 24 participants underwent an additional MRI examination following 3-day topical diclofenac administration. For renal perfusion imaging, a flow-sensitive alternating inversion-recovery TrueFISP ASL sequence was applied. Plasma concentrations of diclofenac and serum concentrations of thromboxane were determined. After oral diclofenac application, large interindividual differences in plasma concentrations were observed (range <3-4604nm). Topical diclofenac application did not result in relevant systemic diclofenac levels (range 5-75nm). MRI showed a significant reduction of renal perfusion in individuals with diclofenac levels ≥225nm (baseline: 347±7 vs diclofenac: 323±8ml/min/100g, P<0.01); no significant differences were observed in participants with diclofenac levels <225nm. Diclofenac levels correlated negatively with thromboxane B2 levels pointing towards target engagement. Single-dose diclofenac caused a decrease in renal perfusion in participants with diclofenac levels ≥225nm. We demonstrated that even a single dose of diclofenac can impair renal perfusion, which could be detrimental in patients with underlying chronic kidney disease or acute kidney injury.