Drug Interactions between ezetimibe / rosuvastatin and mipomersen

MONITOR CLOSELY: Coadministration of mipomersen with other agents known to induce hepatotoxicity may potentiate the risk of liver injury. Mipomersen can cause elevations in serum transaminases and hepatic steatosis. In a premarketing clinical trial, 12% (4/34) of patients treated with mipomersen had at least one elevation in alanine aminotransferase (ALT) 3 times the upper limit of normal (ULN) or greater, and 9% (3/34) had at least one elevation in ALT 5 times ULN or greater, compared to 0% of the 17 patients treated with placebo. There were no concomitant clinically meaningful elevations of total bilirubin, international normalized ratio (INR), or partial thromboplastin time (PTT). Mipomersen also increases hepatic fat, with or without concomitant increases in transaminases. In clinical trials of patients with heterozygous familial hypercholesterolemia and hyperlipidemia, the median absolute increase in hepatic fat was 10% after 26 weeks of treatment, from 0% at baseline, measured by magnetic resonance imaging. The long-term consequences of hepatic steatosis associated with mipomersen therapy are unknown. Hepatic steatosis may be a risk factor for progressive liver disease, including steatohepatitis and cirrhosis.

MANAGEMENT: Caution is advised if mipomersen is used with other potentially hepatotoxic agents (e.g., acetaminophen; alcohol; amiodarone; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; kinase inhibitors; methotrexate; nonsteroidal anti-inflammatory agents; nucleoside reverse transcriptase inhibitors; proteasome inhibitors; retinoids; tamoxifen; tetracyclines; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; other lipid-lowering medications such as fenofibrate, lomitapide, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). Mipomersen has not been studied with other LDL-lowering agents that can also increase hepatic fat, thus concomitant use is not recommended. Patients treated with mipomersen should have serum ALT, AST, alkaline phosphatase, and total bilirubin measured prior to initiation of treatment and regularly during treatment in accordance with the product labeling, and the dosing adjusted or interrupted as necessary. Since alcohol may increase levels of hepatic fat and induce or exacerbate liver injury, the manufacturer recommends that patients taking mipomersen not consume more than one alcoholic drink per day. Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, right upper quadrant pain, dark urine, pale stools, and jaundice.

MONITOR: Coadministration with ezetimibe may rarely increase the risk of myopathy and serum transaminase elevations associated with HMG-CoA reductase inhibitors (i.e., statins). The mechanism of interaction is unknown. A case report describes two patients whose serum creatine kinase increased after ezetimibe was added to their statin therapy (atorvastatin and fluvastatin, respectively). One of the patients also developed myalgia and tendinopathy, which resolved promptly after withdrawal of both drugs. Statin therapy was subsequently reintroduced at the previous dosage without incident. In the other patient, serum creatine kinase returned to normal within 4 weeks after discontinuation of ezetimibe while the statin was continued. On the contrary, no cases of myopathy or tendinopathy occurred in a study of 33 hypercholesterolemic patients treated with ezetimibe and atorvastatin or simvastatin. There were also no reports of myopathy or significant increases in serum creatine kinase in a study of 32 subjects treated with ezetimibe and fluvastatin. In controlled clinical studies, the incidence of consecutive elevations (greater than 3 times the upper limit of normal) in serum transaminases was 1.3% for patients treated with ezetimibe in combination with a statin versus 0.4% for patients treated with a statin alone. These elevations were generally asymptomatic, not associated with cholestasis, and returned to baseline after discontinuation of therapy or with continued treatment.

MANAGEMENT: Until further information is available, use of a statin in combination with ezetimibe should be approached with caution. Some authorities consider concomitant use to be contraindicated in patients with active liver disease or unexplained persistent elevations in serum transaminases. Patients should be advised to promptly report to their physician any unexplained muscle pain, tenderness, or weakness, particularly if accompanied by malaise or fever. The drugs should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed. In addition, liver function tests should be performed at initiation of therapy and according to the recommendations of the HMG-CoA reductase inhibitor.