Warfarin food interactions

Identify and analyze warfarin drug-drug and drug-food interactions. 

Drug/Food interactions Vitamin K-rich vegetables may decrease the anticoagulant effects of warfarin by interfering with absorption. Minimize consumption of vitamin K-rich foods (eg, spinach, seaweed, broccoli, turnip greens) or nutritional supplements. Mango has been shown to increase warfarin s effect. 

The most widely prescribed anticoagulant in North American is warfarin sodium (Coumadin). It was discovered serendipitously in the early 1940s at the University of Wisconsin after hemorrhagic deaths occurred in cattle eating spoiled sweet clover. Warfarin is approved by the FDA for the prevention and treatment of VTE as well as for the prevention of thromboembolic complications associated with atrial fibrillation, heart valve replacement, and myocardial infarction. Because of its narrow therapeutic index, predisposition to drug and food interactions, and propensity to cause hemorrhage, warfarin requires... 

Describe the food interactions that exist with warfarin therapy. 

Holbrook, AM., J.A. Pereira, R. Labiiis, et aL 2005. Systematic overview of warfarin and its drug and food interactions. Arch. Intern. Med. 165(10) 1095-1106. 

Estazolam (Prosom) [C-IV] [Hypnotic/Benzodiazepine] Uses Short-term management of insomnia Action Benzodiazepine Dose 1-2 mg PO qhs PRN -1- in hqjatic impair/elderly/debilitated Caution [X, -] t Effects w/ CNS d ressants Contra PRG Disp Tabs SE Somnolence, weakness, palpitations, anaphylaxis, angioedema, amnesia Interactions t Effects W7 amoxicillin, clarithromycin T effects OF diaz am, phen5rtoin, warfarin X effects W7 food X effects OF azole antifungals, digoxin EMS Use caution w/ other benzodiazepines, may need a reduced dose concurrent EtOH and caffeine use can t CNS effects OD May cause alt ed reflexes, drowsiness, CNS depression, slurred speech, and Szs flumazenU can be used as an antidote... 

Vorinostat (Zolinza) [Histone Deacetylase Inhibitor] Uses Rx cutaneous manifestations in cutaneous T-cell lymphoma Action Histone deacetylase inhibitor Dose 400 mg PO daily w/ food if intolerant X 300 mg PO d for X 5 d each wk Caution [D /-] w/ warfarin (t INR) Disp Caps SE NA /D, dehydration, fatigue, anorexia, dysgeusia, DVT, PE, Xplt, anemia, hypoglycemia, QT prolongation Interactions t Risk of thrombocytopenia GI bleed W/HDAC inhibitors (valproic acid) EMS May t QT interval, monitor ECG may t glucose T risk of DVT has been r orted OD Sxs unknown... 

Some chemical exposures may be hepatic enzyme inducers/inhibitors, altering the effects of drugs like warfarin. Some foods such as mono-amines, will cause reactions in patients given MAOIs grapefruit juice may interact with terfenadine and some other drugs. New diseases may cause problems heart failure causing reduced liver blood flow can reduce the metabolism of drugs like warfarin. 

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