Gemfibrozil and statins

Prueksaritanont T, Zhao JJ, Ma B, et al. Mechanistic studies on metabolic interactions between gemfibrozil and statins. Pharmacol Exp Ther 2002 301(3) 1042-1051. 

Fibrates are the most effective triglyceride-lowering agents and also raise HDL cholesterol levels. Combination therapy with a fibrate, particularly gemfibrozil, and a statin has been found to increase the risk for myopathy. Of the 31 rhabdomyolysis deaths reported with cerivastatin use, 12 involved concomitant gemfibrozil.25 Therefore, more frequent monitoring, thorough patient education, and consideration of factors that increase the risk as reviewed previously should be considered. 

The British National Formulary (BNF) recommends that fibrates or nicotinic acid should not be combined with statins because of the potential for myopathy and rhabdomyolysis with this combination [54]. This is widely discussed in the medical literature. Numerous deaths have been reported and the high mortality associated with concurrent use of cerivastatin and gemfibrozil was partly instrumental in the decision to withdraw cerivastatin from the market in 2001 [34]. It appears that the high mortality in patients using concurrent gemfibrozil and cerivastatin was due to interactions at the level of glucuronidation, CYP2C8 inhibition and OATP inhibition [17, 55]. 

All fibrates increase the lithogenicity of bile. Clofibrate has been associated with increased risk of gallstone formation gemfibrozil and fenofibrate reportedly do not increase biliary tract disease. Renal failure and hepatic dysfunction are relative contraindications to fibrate therapy. Combined statin-fibrate therapy should be avoided in patients with impaired renal function. Gemfibrozil should be used with caution and at a reduced dosage to treat the hyperlipidemia of renal failure. Fibrates should not be used by children or pregnant women. 

It has been an attractive option to use combination therapy of statin and fibrate when HDL remains low but there is no data from RCTs to support this approach. It is ironic that gemfibrozil with the best outcome data should not be used in this context given drug interactions. The results of the FIELD trial with fenofibrate as sole therapy were disappointing [59] however, a combination trial with fenofibrate and statin in type 2 diabetes, the ACCORD study, is in progress. 

LC-ESI-MS/MS has been used to determine lipid-regulating agents, including the fibrates and statins classes in water. For the fibrates, N1 mode was generally employed with deprotonated molecules [M — H] at m/z 213 for clofibric acid, m/z 249 for gemfibrozil, and m/z 360 for bezafibrate [85,87,140,147]. However, PI mode was also used for fenofibrate and bezafibrate [86]. In ESI(—) tandem MS mode, the deprotonated molecule of clofibric... 

Because the costs for chronic preventative pharmacotherapy are the same for primary and secondary prevention, while the risk of events is higher with secondary prevention, secondary prevention is more cost effective than primary prevention of CHD. Pharmacotherapy demonstrating cost effectiveness to prevent death in the ACS and post-MI patient includes fibrinolytics ( 2,000 to 33,000 cost per year of life saved), aspirin, glycoprotein Ilb/IIIa receptor blockers ( 13,700 to 16,500 per year of life added), (3-blockers (less than 5,000 to 15,000 cost per year of life saved), ACE inhibitors ( 3,000 to 5,000 cost per year of life saved), eplerenone ( 15,300 to 32,400 per year of life gained), statins ( 4,500 to 9,500 per year of life saved) and gemfibrozil ( 17,000 per year of life saved).49-58 Because cost-effectiveness ratios of less than 50,000 per added life-year are considered economically attractive from a societal perspective,49 pharmacotherapy described above for ACS and secondary prevention are standards of care because of their efficacy and cost attractiveness to payors. 

Gemfibrozil 600 mg tablets 1200 mg/day in two doses, 30 minutes before meals abdominal pain, and rash. Increased risk of rhabdomyolysis when given with a statin. Fibric acids are associated with gallstones, myositis, and hepatitis. 

Specific concomitant medications or consumptions (check specific statin package insert for warnings) fibrates (especially gemfibrozil, but other fibrates too), nicotinic acid (rarely), cyclosporine, azole antifungals such as itraconazole and ketoconazole, macrolide antibiotics such as erythromycin and clarithromycin, protease inhibitors used to treat Acquired Immune Deficiency Syndrome, nefazodone (antidepressant), verapamil, amiodarone, large quantities of grapefruit juice (usually more than 1 quart per day), and alcohol abuse (independently predisposes to myopathy)... 

Hyperlipidemia Diet HMG-CoA reductase inhibitors (stati ns) Gemfibrozil Ezetemibe CSA greater than TAC consider switch to TAC discontinue or hold SRL CSA/TAC may increase statin levels start at lowest dose Monitor for muscle cramps, CPK levels and LFTs Adjust dose in those with Rl Caution with concomitant statin Often used in combination with a statin... 

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