May inhibit absorption & efficacy w/ cholestyramine, colestipol or antacids containing Al hydroxide &/or smectite (Al oxide). May affect the absorption of ciclosporin. May reduce the absorption of ciprofloxacin. Slightly elevate plasma levels of rosuvastatin. Reduce peak plasma conc (C
max) & AUC of nitrendipine. Reduced therapeutic effect of dapsone. Increase hepatic cholesterol secretion & biliary lithiasis w/ oestrogenic hormones & blood cholesterol lowering agents eg, clofibrate.