From the FDA Drug Label
Ezetimibe is primarily metabolized in the small intestine and liver via glucuronide conjugation (a phase II reaction) with subsequent biliary and renal excretion. Approximately 78% and 11% of the administered radioactivity were recovered in the feces and urine, respectively, over a 10-day collection period. Ezetimibe was the major component in feces and accounted for 69% of the administered dose, while ezetimibe-glucuronide was the major component in urine and accounted for 9% of the administered dose
Zetia (ezetimibe) is renally excreted, but to a lesser extent than biliary excretion. The majority of the drug is excreted in the feces, with a smaller percentage excreted in the urine 1.
From the Research
Zetia (ezetimibe) is primarily eliminated through fecal excretion, not renal excretion, with approximately 78% of the dose excreted in the feces and the balance found in the urine mainly as ezetimibe-glucuronide. The drug undergoes extensive glucuronidation in the small intestine and liver to form ezetimibe-glucuronide, which is the active metabolite 2. Both ezetimibe and its glucuronide metabolite circulate in the enterohepatic cycle, where they are repeatedly secreted into bile and reabsorbed from the intestine. This cycling extends the drug's duration of action. Despite its elimination pathway, no dosage adjustment is typically required for patients with mild to moderate renal impairment or mild-to-severe renal insufficiency, as stated in the study published in Clinical Pharmacokinetics 2. However, caution is still advised when using Zetia in patients with severe renal impairment as limited data exists for this population. The standard dosage remains 10 mg once daily regardless of renal function.
Some key points to consider when prescribing Zetia include:
- The drug's mechanism of action, which involves inhibiting the intestinal absorption of cholesterol 3, 4
- The potential for drug interactions, particularly with bile acid sequestrants and fibrates 2, 5
- The importance of monitoring lipid profiles and adjusting treatment as needed to achieve optimal cholesterol levels 5, 6
- The potential benefits and risks of combining Zetia with other lipid-lowering therapies, such as statins and bile acid sequestrants 5, 6