of patients), hypersensitivity reactions (rash, angioedema) or myopathy may occur. Cases of muscle problems (myalgia and rhabdomyolysis) have been reported and are included as warnings on the label for ezetimibe. Since NPC1L1 also regulates vitamin K uptake, the use of ezetimibe can lead to side effects in warfarin therapy. Overdose The incidence of overdose with ezetimibe is rare; subsequently, few data exist on the effects of overdose. However, an acute overdose of ezetimibe is expected to produce an exaggeration of its usual effects, leading to loose stools, abdominal pain, and fatigue. Pharmacology Mechanism of action Ezetimibe inhibits the absorption of cholesterol from the small intestine and decreases the amount of cholesterol normally available to liver cells. The lower levels of cholesterol in the liver cells leads them to absorb more cholesterol from circulation and thus lowering the levels of circulating cholesterol. It blocks the critical mediator of cholesterol absorption, the Niemann-Pick C1-like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells, as well as in hepatocytes; it blocks aminopeptidase N and interrupts a caveolin 1–annexin A2 complex involved in trafficking cholesterol. Pharmacokinetics Within 4–12 hours of the oral administration of a 10-mg dose to fasting adults, the attained mean ezetimibe peak plasma concentration (Cmax) was 3.4–5.5 ng/ml. Following oral administration, ezetimibe is absorbed and extensively conjugated to a phenolic glucuronide (active metabolite). Mean Cmax (45–71 ng/ml) of ezetimibe-glucuronide is attained within 1–2 hours. The concomitant administration of food (high-fat vs. nonfat meals) has no effect on the extent of absorption of ezetimibe. However, coadministration with a high-fat meal increases its Cmax by 38%. The absolute bioavailability cannot be determined, since ezetimibe is insoluble in aqueous media suitable for injection. Ezetimibe and its active metabolites are highly bound to human plasma proteins (90%). Ezetimibe is primarily metabolized in the liver and the small intestine via glucuronide conjugation with subsequent renal and biliary excretion. Both the parent compound and its active metabolite are eliminated from plasma with a half-life around 22 hours, allowing for once-daily dosing. Ezetimibe lacks significant inhibitor or inducer effects on cytochrome P450 isoenzymes, which explains its limited number of drug interactions. No dose adjustment is needed in patients with chronic kidney disease or mild hepatic dysfunction (Child-Pugh score 5–6). Due to insufficient data, the manufacturer does not recommend ezetimibe for patients with moderate to severe hepatic impairment (Child-Pugh score 7–15). In patients with mild, moderate, or severe hepatic