Drug Interactions between mipomersen and thioguanine

GENERALLY AVOID: Coadministration with alcohol may increase the risk of hepatotoxicity associated with the use of mipomersen. 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: 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.

MONITOR: The concomitant or sequential use of other agents known to induce hepatotoxicity may potentiate the risk of liver injury associated with thioguanine. A high risk of liver toxicity characterized by vascular endothelial damage has been reported with long-term continuous use of thioguanine, particularly in children receiving the drug as part of maintenance therapy for acute lymphoblastic leukemia and in other conditions associated with continuous use. Liver toxicity usually presents as the clinical syndrome of hepatic veno-occlusive disease (hyperbilirubinemia, tender hepatomegaly, weight gain due to fluid retention, and ascites) or with signs of portal hypertension (splenomegaly, thrombocytopenia, and esophageal varices). Histopathological features include hepatoportal sclerosis, nodular regenerative hyperplasia, peliosis hepatitis, and periportal fibrosis.

MANAGEMENT: The risk of hepatic injury should be considered when thioguanine is used with other potentially hepatotoxic agents (e.g., acetaminophen; alcohol; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; ketolide and macrolide antibiotics; kinase inhibitors; minocycline; nonsteroidal anti-inflammatory agents; nucleoside reverse transcriptase inhibitors; proteasome inhibitors; retinoids; sulfonamides; tamoxifen; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; lipid-lowering medications such as fenofibrate, lomitapide, mipomersen, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). 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. Baseline and regular monitoring of hepatic function is recommended. Thioguanine therapy should be discontinued if there is evidence of toxic hepatitis or biliary stasis, as reversal of signs and symptoms of liver toxicity have been reported upon withdrawal. Early indications of liver toxicity are signs associated with portal hypertension such as thrombocytopenia out of proportion with neutropenia and splenomegaly. Elevations of liver enzymes have also been reported, but do not always occur.