Gemfibrozil adverse effects

Action HMG-CoA reductase inhibitor Dose 5-40 mg PO daily max 5 mg/d w/cyclosporine, 10 mg/d w/gemfibrozil or CrCl <30 mL/rain (avoid Al-/Mg-based antacids for 2 h after) Caution [X, /-] Contra Active liver Dz, unexplained T LFT Disp Tabs SE Myalgia, constipation, asthenia, abd pain, N, myopathy, rarely rhabdomyolysis Interactions T Effects OF warfarin T risk of myopathy W/ cyclosporine, fibrates, niacin, statins EMS T Effects of warfarin concurrent EtOH use can T risk of liver tox Asian pts have an T risk of adverse effects OD Unlikely to cause life-threatening Sxs... 

Nervous system adverse effects are rare, constituting 0.5% of all adverse effects (2). Gemfibrozil-induced headache has been reported (3) and occurred in one patient... 

Fibrates should be avoided in gallbladder disease or any form of obstructive jaundice because of the risk of stone formation. The extended therapeutic effect of gemfibrozil, which is due to enterohepatic recycling, may be reduced in obstructive jaundice. Fibrates may have an adverse effect on coagulation if used, the INR/PT should be monitored... 

Gemfibrozil activates lipoprotein lipase, thus decreasing VLDL, TG, and LDL levels. The adverse effects are listed. 

C. Toxicity Nausea is the most common adverse effect with all members of this subgroup. Skin rashes are common with gemfibrozil. A few patients show decreases in white blood count or hematocrit, and these drugs can potentiate the action of anticoagulants. There is an increased risk of cholesterol gallstones these drugs should be used with caution in patients with a history of cholelithiasis. 

In order to reduce the risk of myopathy the CSM in the UK have advised that statins should be used with care in patients who are at increased risk of this adverse effect. Among other risk factors, they mention concomitant use with fibrates, such as gemfibrozil , (p.llOO), and with inhibitors of CYP3A4 such as ciclosporin , (p.l097), macrolides ,(p.ll04), azoles , (p.l093), and protease inhibitors , (p.1108). They also recommend that patients should be made aware of the risks of myopathy and rhabdomyolysis, and asked to promptly report muscle pain, tenderness, or weakness, especially if accompanied by malaise, fever, or dark urine. A 2002 advisory on the use of statins gives some important safety recommendations, which are useful in the context of interactions ... 

In a randomised, crossover study 15 patients were given fluvastatin 20 mg and gemfibrozil 600 mg twice daily. The pharmacokinetics of both gemfibrozil and fluvastatin were unchanged by concurrent use and no significant adverse effects were noted."... 

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