ProUrsan Drug Interactions

Ursodeoxycholic Acid (ProUrsan) should not be administered concomitantly with cholestyramine, colestipol or antacids containing aluminium hydroxide and/or smectite (aluminium oxide), because these preparations bind ursodeoxycholic acid in the intestine and thereby inhibit its absorption and efficacy. Should the use of a preparation containing one of these active substances be necessary, it must be taken at least 2 hours before or after Ursodeoxycholic Acid (ProUrsan).
Ursodeoxycholic Acid (ProUrsan) can affect the absorption of ciclosporin from the intestine. In patients concurrently receiving this substance, concentrations of cyclosporine should therefore be checked and its dose adjusted if necessary.
In sporadic cases, Ursodeoxycholic Acid (ProUrsan) can reduce the absorption of ciprofloxacin.
In a clinical study in healthy volunteers concomitant use of UDCA (500 mg/day) and rosuvastatin (20 mg/ day) resulted in slightly elevated plasma levels of rosuvastatin. The clinical relevance of this interaction also with regard to other statins is unknown.
The ursodeoxycholic acid was demonstrated to decrease the maximum plasma concentration (C_max) and the area under the curve (AUC) of nitrendipine, a calcium antagonist in healthy volunteers. It is recommended to carefully monitor the result of concurrent administration of nitrendipine and ursodeoxycholic acid. The nitrendipine dose may need to be increased. A decreased therapeutic effect of dapsone was observed. This observation, together with in vitro findings, indicated the potential of ursodeoxycholic acid to induce P450 3A cytochrome. However, no induction was observed in a well designed study of an interaction with budesonide, a known P450 3A cytochrome substrate.
Oestrogenic hormones and blood cholesterol lowering agents such as clofibrate increase hepatic cholesterol secretion and may therefore encourage biliary lithiasis, which is a counter-effect to ursodeoxycholic acid used for dissolution of gallstones.