Medication Overview
Ezetimibe (Zetia) is a cholesterol absorption inhibitor that works by:
- Selectively inhibiting intestinal uptake of cholesterol at the brush border of the small intestine
- Binding to the Niemann-Pick C1 Like 1 (NPC1L1) protein, which prevents cholesterol absorption
- Reducing both dietary and biliary cholesterol absorption without affecting absorption of fat-soluble vitamins or triglycerides 2
Clinical Efficacy
Ezetimibe provides significant lipid-lowering benefits:
- As monotherapy: Reduces LDL cholesterol by approximately 15-20% 1
- As add-on to statin therapy: Provides an additional 25% reduction in LDL-C 2
- In the IMPROVE-IT trial, adding ezetimibe to statin therapy demonstrated cardiovascular benefit, especially among patients with type 2 diabetes 3
Pharmacokinetic Properties
- Rapidly absorbed after oral administration and extensively metabolized (>80%) to the pharmacologically active ezetimibe-glucuronide
- Maximum concentrations reached 1-2 hours after administration
- Terminal half-life of approximately 22 hours
- Can be administered once daily (10 mg) without regard to food or time of day 4
- Undergoes enterohepatic recirculation which ensures repeated delivery to the intestinal site of action while limiting peripheral exposure 2
Clinical Applications
Ezetimibe is commonly used in:
- Patients who need modest LDL-C reductions (15-20%)
- Patients intolerant to statins or other lipid-lowering medications
- Combination therapy with statins when:
- Patients with statin-associated muscle symptoms, as a non-statin alternative 3
Safety Profile
Ezetimibe is generally well-tolerated:
- Adverse event profile similar to placebo when used as monotherapy
- No significant effects on major drug metabolizing enzymes (CYP450), reducing potential drug interactions
- Most common side effects include mild gastrointestinal discomfort 3, 4
Important Drug Interactions
- No clinically significant interactions with most commonly prescribed medications
- Should be administered several hours apart from bile acid sequestrants (like colestyramine) to avoid reduced bioavailability
- Caution advised when co-administered with cyclosporine 4
Ezetimibe represents an important option in the lipid management armamentarium, particularly for patients who cannot achieve LDL-C goals with statins alone or who experience statin intolerance.