Influenza vaccines Warfarin

E Kramer, M, Tsuru, C. E. Cook, C. J. McClain, and J. L. Holtzman, Effect of influenza vaccine on warfarin anticoagulation, Clin. Pharmacol. Therap., 35 416-418 (1984). 

Gomohn IH, Chapron DJ, Luhan PA. Lack of effect of influenza vaccine on theophylUne levels and warfarin anticoagulation in the elderly. J Am Geriatr Soc 1985 33(4) 269-72. 

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 alcohol, anticoagulants, antihistamines, betamethasone, brompheniramine, buclizine, buprenorphine, chlorpheniramine, darunavir, dasatinib, delavirdine, dexamethasone, dicumarol, ethanolamine, fesoterodine, fluconazole, flunisolide, fosamprenavir, hydrocortisone, imatinib, influenza vaccines, lacosamide, lapatinib, lopinavir, meperidine, methylprednisolone, midazolam, nilotinib, piracetam, pizotifen, prednisolone, prednisone, rivaroxaban, rufinamide, solifenacin, telithromycin, temsirolimus, teniposide, trabectedin, triamcinolone, warfarin... 

Patriarca PA, Kendal AP, Stricof RL, Weber JA, Meissner MK, Dateno B. Influenza vaccination and warfarin or theophylline toxicity in nursing-home residents. NEngl J A/erf(1983) 308, 1601-2. 

Lipsky BA, Pecoraro RE, Roben NJ, de Blaquiere P, Delaney CJ. Influenza vaccination and warfarin anticoagulation. Ann Intern Med (1984) 100, 835-7. 

Scott AK, Cannon J, Breckenridge AM. Lack of effect of influenza vaccination on warfarin in healthy volunteers. BrJ Clin Pharmacol (1984) 19, 144P-145P. 

Weibert RT, Lorentz SM, Norcross WA, Klauber MR, Jagger PI. Effect of influenza vaccine in patients receiving long-term warfarin therapy. Clin Pharm (1986) 5, 499-503. 

Arnold WSG, Mehta MK, Roberts JS. Influenza vaccine and anticoaguladon control in patients receiving warfarin. Br J Clin Pract ) 44, 136-9. 

Bussey HI, Saklad JJ. Effect of influenza vaccine on chronic warfarin therapy. Drugintell Clin Pharm (1988) 22, 198 201. 

The concurrent use of warfarin and influenza vaccine is usually safe and uneventful, but there are reports of bleeding in a handful of patients (life threatening in one case) attributed to an interaction. Acenocoumarol also does not normally interact... 

In a randomised study in 26 patients stabilised on warfarin, there was no difference in injection site adverse events between intramuscular or subcutaneous injection of a standard trivalent influenza vaccine, and no patient had bruising or swelling. In addition, both routes of administration produced similar levels of antibody titres. In another study that specifically assessed the local reactions to intramuscular influenza vaccination, there were no detectable local complications after intramuscular injection, including no change in arm circumference. ... 

Not understood. In a placebo-controlled study in healthy subjects, influenza vaccine did not alter the half-life of either/ - orS-warfarin. It has therefore been suggested that when an interaction occurs the synthesis of the blood clotting factors is altered. ... 

A well-investigated interaction, but with some contradictory data. The weight of evidence shows that influenza vaccination in those taking warfarin is normally safe and uneventful, nevertheless it would be prudent to be on the alert because very occasionally and unpredictably bleeding may occur. Acenocoumarol appears not to be affected. 

A 64-year-old man with a 2-day history of bleeding from the rectum became unresponsive. He had taken long-term warfarin because of atrial fibrillation and had received an inactivated influenza vaccine 1 month before admission. The INR was raised, after having been stable for at least 6 months. A CT scan showed a large parenchymal hemorrhagic infarct involving the left temporal, parietal, and occipital lobes. He died about 17 hours after admission. 

Carroll DN, Carroll DG. Fatal intracranial bleed potentially due to a warfarin and influenza vaccine interaction. Ann Phar-macother 2009 43 754-60. 

Farrow PR, Nicholson KG. Lack of effect of influenza and pneumococcal vaccines on anticoagulation by warfarin. J Infect (1984) 9, 157-60. 

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