Ibuprofen Ciprofibrate

Acute renal insufficiency occurred in one patient taking ciprofibrate 100 mg/day and ibuprofen 400 mg/day (84). Both drugs are highly protein-bound and contain propionic acid groups. Thus, ibuprofen may displace ciprofibrate. 

Ramachandran S, Giles PD, Hartland A. Acute renal failure due to rhabdomyolysis in presence of concurrent ciprofibrate and ibuprofen treatment. BMJ 1997 314(7094) 1593. 

Carboxylic acid-containing drugs benoxaprofen, ciprofibrate, clofibric acid, difiunisal, dimethylxanthenone-4-acetic acid (DMXAA), fenoprofen, ibuprofen, indomethacin, ketoprofen, naproxen, pitavastatin, simvastatin acid, tiaprofenic acid, valproic acid, zaltoprofen, zomepirac. 

Carboxyl group clofibrate, ciprofibrate, etodolac, fenoprofen, ibuprofen, ketoprofen, naproxen (racemic > 5), valproic acid and formation of simvastatin and atorvastatin lactones via an intermediate acyl glucuronide Tertiary amines amitriptyline, chlorpheniramine, chlorpromazine, clozapine, cyproheptadine, diphenylamine, doxepin, imipramine, ketotifen, loxapine, promethazine, tripellenamine, trifluoperazine Aromatic heterocyclic amines croconazole, lamotrigine, nicotine (30X velocity than UGT1A3), 1-phenylimidazole, posaconazole, retigabine Primary and secondary amines ... 

An isolated report describes a patient taking ciprofibrate who developed acute renal failure and rhabdomyolysis after taking ibuprofen. 

A 29-year-old man with type M hyperlipidaemia who had been taking ciprofibrate 100 mg daily for 6 months began to take ibuprofen 200 mg and then 400 mg daily for a painful heel. The pain became general, his urine turned muddy , he complained of having a stiffbody , and he rap-... 

The reasons for this reaction are not known, but the authors of the report postulate that the ibuprofen displaced the ciprofibrate from its binding sites, thereby turning a safe dose into a toxic one. However, it should be said that this mechanism of interaction is rarely important on its own, so it seems likely that some other factors may have contributed to what happened. 

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