Pharmacology Notes

Bile-acid-binding resins bind bile salts in the gut. By increasing the need for cholesterol to replace the lost bile acids they stimulate expression by hepatocytes of low-density lipoprotein (LDL) receptors on their surface and thus uptake of LDL from the blood. They tend to increase plasma triglyceride levels. The bile-acid-binding resins available in Australia are cholestyramine and colestipol.

Both drugs are inconvenient to take and often cause nausea, gastro-oesophageal reflux and constipation. They can bind drugs (eg anticoagulants, thyroxine, cyclosporin, digoxin) and interfere with their absorption, which can reduce their efficacy. To reduce the potential for interactions, give other drugs at least 1 hour before, or 4 to 6 hours after, the resin.