Gemfibrozil Warfarin

Rindone JP, Keng HC. Gemfibrozil-warfarin drug interaction resulting in profound hypoprothrombinemia. Chest 1998 114(2) 641-2. 

Clinically important, potentially hazardous interactions with ciprofibrate, cyclosporine, eltrombopag olamine, gemfibrozil, warfarin... 

Lovastatin (Mevacor/ Altocor) [Antilipemic/HMG-CoA Reductase Inhibitor] Uses Hypercholesterolemia Action HMG-CoA reductase inhibitor Dose 20 mg/d PO w/ PM meal may T at 4-wk intervals to 80 mg/d max or 60 mg ER tab take w/ meals Caution [X, -] Avoid w/ grapefruit juice, gemfibrozil. Contra Active liver Dz Disp Tabs SE HA GI intolerance common promptly report any unexplained muscle pain, tenderness, or weakness (myopathy) Interactions T Effects W/ grapefruit juice T risk of severe myopathy W/ azole antifungals, cyclosporine, erythromycin, gemfibrozil, HMG-CoA inhibitors, niacin T effects OF warfarin >1 effects W/ isradipine, pectin EMS t Risk of photosensitivity Rxns T effects of warfarin concurrent EtOH use t risk of liver tox diltiazem and verapamil can T risk of lovastatin tox OD Unlikely to cause life-threatening Sxs... 

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/min (avoid Al-/Mg-based antacids for 2 h after) Caution [X, /-] Contra Active Uvct Dz, unej lained 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 advise effects OD Unlikely to cause life-threatening Sxs... 

Drug Interactions Cyclosporine Gemfibrozil Niacin Erythromycin Cholestyramine/Colestipol Warfarin Cimetidine Digoxin ... 

Drug Interactions Gemfibrozil Niacin Erythromycin Cholestyramine Digoxin Cimetidine/ranitidine/ omeprazole Rifampicin Warfarin Itraconazole Gemfibrozil Niacin Erythromycin Propranolol Digoxin Warfarin Antacids Colestipol Digoxin Erythromycin Oral contraceptives Fibrates Niacin Azole antifungals... 

Simvastatin (Zocor) [Anrilipemic/HMG-CoA Reductase Inhibitor] Uses X Cholesterol Action HMG-CoA reductase inhibitor Dose Adults. 5-80 mg PO w/ meals X in renal insuff Peds. 10-17 y 10 mg, 40 mg/daily max Caution [X, —] Avoid concurrent use of gemfibrozil Contra PRG, liver Dz Disp Tabs 5,10, 20, 40, 80 mg SE HA, GI upset, myalgia, myopathy (muscle pain, tenderness or weakness w/ creatine kinase 10 x ULN), Hep Interactions T Effects OF digoxin, warfarin T risk of myopathy/iiiabdomyolysis W/ amiodarone, cyclosporine, CYP3A4 inhibitors, fibrates, HIV protease inhibitors, macrolides, niacin, verapamil, grapefruit juice X effects W/ cholestyramine, colestipol, fluvas-tatin, isradipine, propranolol EMS T Effects of warfarin use amiodarone and... 

Lilja JJ, Backman JT, Neuvonen PJ. Effect of gemfibrozil on the pharmacokinetics and pharmacodynamics of racemic warfarin in healthy subjects. Br J Clin Pharmacol 2005 59 433439. 

Several interactions between warfarin and hypohpidemic drugs have been described (SEDA-21, 459), including clinically important potentiation of warfarin by bezafibrate (73) and gemfibrozil (74). Two patients developed a significantly increased anticoagulant effect of warfarin while taking fenofibrate (75). 

Fibric adds Clofibrate Gemfibrozil Fenofibrate Increase VLtt-catabolism PPAR , agonist LDLi 5-20% HDL t 10%-20% TG i 20%-S0% Gl upset, dyspepsia, gallstones, T LFTs, myopathy Nonmetabolism Warfarin Cyclosporine Statins Liver or severe renal disease primary biliary cirrhosis preexisting gallbladder disease... 

Clinically important, potentially hazardous interactions with amiloride, aminoglycosides, amphotericin B, ampicillin, anisindione, anticoagulants, armodafinil, atorvastatin, azathioprine, azithromycin, bacampicillin, basiliximab, bezafibrate, bosentan, bupropion, carbenicillin, caspofungin, cholestyramine, clarithromycin, cloxacillin, co-trimoxazole, corticosteroids, cyclophosphamide, daclizumab, danazol, dicloxacillin, dicumarol, digoxin, diltiazem, disulfiram, echinacea, erythromycin, ethotoin, etoposide, ezetimibe, flunisolide, fluoxymesterone, fluvastatin, foscarnet, fosphenytoin, gemfibrozil, hemophilus B vaccine, HMG-CoA reductase inhibitors, imatinib, imipenem/cilastatin, influenza vaccines, ketoconazole, lanreotide, lopinavir, lovastatin, mephenytoin, methicillin, methoxsalen, methylphenidate, methylprednisolone, methyltestosterone, mezlocillin, mizolastine, mycophenolate, nafcillin, nisoldipine, NSAIDs, orlistat, oxacillin, penicillins, phellodendron, phenytoin, pravastatin, prednisolone, prednisone, pristinamycin, ranolazine, red rice yeast, rifabutin, rifampin, rifapentine, ritonavir, rosuvastatin, simvastatin, sirolimus, spironolactone, St John s wort, sulfacetamide, sulfadiazine, sulfamethoxazole, sulfisoxazole, sulfonamides, tacrolimus, telithromycin, tenoxicam, testosterone, ticarcillin, tolvaptan, trabectedin, triamterene, troleandomycin, ursodeoxycholic acid, vaccines, vecuronium, warfarin, zofenopril... 

Clinically important, potentially hazardous interactions with amiodarone, atazanavir, azithromycin, bosentan, ciprofibrate, clarithromycin, clopidogrel, cyclosporine, darunavir, delavirdine, diltiazem, erythromycin, fosamprenavir, fusidic acid, gemfibrozil, grapefruit juice, imatinib, itraconazole, lopinavir, rabeprazole, ranolazine, red rice yeast, ritonavir, roxithromycin, selenium, St John s wort, tacrolimus, telithromycin, tipranavir, verapamil, warfarin... 

Figure 17.4 Compounds which are mentioned throughtout the chapter and numbered in the main text as follows (1) DMZ, (2) diclofenac, (3) flurbiprofen, (4) warfarin, (5) fluconazole, (6) coumarin, (7) dapsone, (8) retinoic acid, (9) arachidonic acid, (10) troglitazone, (11) fluvastatin, (12) cerivastatin, (13) taxol, (14) gemfibrozil, (15) verapamil, (16) amodiaquine, (17) amiodarone, (18) metyrapone, (19) progesterone, (20) testosterone, (21) erythromycin, (22) ketoconazole, (23) nicotine, (24) IV -Nitrosonor-nicotine, (25) 4-(Methylnitrosamino)-l-(3-pyridyl)-l-butanone...

A patient taking warfarin bled, and was found to have an INR of 18 when his gemfibrozil was replaced by fenofibrate. ... 

Uncertain. Clofibrate can displace warfarin from its plasma protein binding sites, but this does not adequately explain the interaetion. Another suggestion is that the fibrates have an additive pharmacodynamic effect. Altered metabolism may also account for the interaetion with ciprofibrate, since this decreased the clearance of 5-warfarin. However, this did not occur with clofibrate or gemfibrozil. ... 

Ahmad S. Gemfibrozil interaction with warfarin sodium (Coumadin). Chest(l990 ) 98,1041-2. 

Fibrates An interaction of gemfibrozil with warfarin has been described in a 62-year-old man, whose INR rose to 5.8 within 3 weeks of the addition of gemfibrozil 600 mg bd. The authors recommended a dosage reduction of 20% and close monitoring during administration of this combination [39. ... 

Dixon DL, Williams VG. Interaction between gemfibrozil and warfarin case report and review of the literature. Pharmacotherapy 2009 29(6) 744-8. 

Waifann An interaction of gemfibrozil with warfarin [SED-15, 1361] has again been described and the interaction reviewed [20" ]. 

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