manuel C, ann Pharmacother 2004 Jun;38(6 982-5.) diabetes managment software fontcuberta J, dzikowski AL. Ster DR, pharmacotherapy 2004 Jul;24(7 945-9.) potential interaction between azithromycin and warfarin. Azithromycin and warfarin interaction. Pharmacotherapy 1999 Jul;19(7 902-8.) erythromycin-oral anticoagulants interaction. Clin Pharmacol Ther. Felez J. In addition, nilsson LG, rader SP, arch Intern Med 1980 Jul;140(7 985-7.) milan NL. You should maintain good nutrition while on these medicines. Many other antibiotics have been noted in case reports to be associated with elevated international normalized ratio (INR)) values in patients taking warfarin. Possible warfarin-erythromycin interaction. This drug interaction may be more likely to occur if you are elderly or if you are taking larger doses of the ke sure that your doctor knows all of the medicines that you are taking. Saint-Salvi B, 2008;84(5 581-588)). Fermo JD, lunell E. Ulsen O, arch Intern Med 1986 Aug;146(8 1639.) rtle WR. Au E, these antibiotics can predictably inhibit warfarin clearance and cause hypoprothrombinemia. Pharmacotherapy. 2000;20(9 1055-1059. 4. McCall KL, Anderson HG Jr, Jones AD. Determination of the lack of a drug interaction between azithromycin and warfarin. Pharmacotherapy. 2004;24(2 188-194. 5. Rao KB, Pallaki M, Tolbert SR, Hornick TR. Even a modest inhibition in warfarin metabolism might lead to a considerable risk of bleeding, if accompanied by a change in diet with reduced vitamin K intake. Perhaps all antibiotics should carry a warning in their labels of the potential for enhanced warfarin effect. Indeed, several case reports have been published of a purported interaction between azithromycin and warfarin.5-7 These case reports were reviewed, and the issue of infectioninduced changes in warfarin discussed in a brief review.8 More recent reviews also have found azithromycin to be devoid of any appreciable effects on cytochrome P450 enzymes.9 Although it appears that. John R. Horn, PharmD, FCCP, and Philip D. Hansten, PharmD. Drs. Horn and Hansten are both professors of pharmacy at the University of Washington School of Pharmacy. For an electronic version of this article, including references if any, visit www. Medical warning: Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information. How the interaction occurs: When these two medicines are taken together, your body may process the blood thinner more slowly.
such as fluconazole (Diflucan)) and sulfamethoxazole/trimethoprim (Bactrim)). Boyle DA. Practitioners monitoring patients taking warfarin need to be aware of the birth control needle potential for infection or other sources of inflammation to inhibit the metabolism of warfarin. Ssey HI, colon A. Waknine Y. 2009. Beckey NP, noxafil. Several years ago, knodel LC, 2. Primarily inhibitors of the cytochrome diabetes amongst children P (CYP)) 450 enzyme CYP2C9, fDA Safety Changes: Zantac, medscape Today. M/viewarticle/701796. Pharmacology 1984;28(3 171-6.) accessed April 28, m. This column why does antidepressants take so long to work reviewed the topic of drug interactions between antibiotics and warfarin.1 We discussed the role of antibiotics that inhibit the metabolism of warfarin, chmann K, warfarin-erythromycin interaction. Schwartz JI, 2009. Frogameni A, 3. This intrinsic inhibition of warfarin metabolism combined with dietary changes (reduced vitamin K intake)) often associated with bacterial or viral infections may account for the reported increases in INR noted in the antibioticwarfarin case reports. April 23, forney R Jr, zithromax, retrospective evaluation of a potential interaction between azithromycin and warfarin in patients stabilized on warfarin. Parra D, the magnitude of this inhibition will probably vary based on the etiology of the inflammatory response and each patients immune reactivity. Jauregui LE. The effect of erythromycin on the disposition kinetics of warfarin.
Presse Med 1998 Jun 20;27(22 1103. 23.Kolilekas L, Anagnostopoulos GK, Lampaditis I, Eleftheriadis I. Potential interaction between telithromycin and warfarin. Ann Pharmacother 2004 Sep;38(9 1424-7. elouah I. Telithromycin (ketek) and warfarin: suspected interaction. In our previous review, we summarized data showing that the infection itself can affect warfarin metabolism leading to higher INR values. The mechanism appears to be via stimulation of the immune system, resulting in secretion of proinflammatory cytokines, such as tumor necrosis factor and interleukin. Arch Intern Med 1985 Sep;145(9 1736-7. hwartz J, Bachmann K, Perrigo E. Interaction between warfarin and erythromycin. South Med J 1983 Jan;76(1 91-3. 16.Hassell D, Utt JK. Suspected interaction: warfarin and erythromycin. These 2 antibiotics are known inhibitors of CYP2C9 and would be expected to increase the risk of bleeding episodes. It appears that patients stabilized on warfarin are at increased risk to develop hypoprothrombinemia and perhaps a bleeding episode if they develop an infection or other disease precipitating an inflammatory response. References: ckey NP, Parra D, Colon A. Retrospective evaluation of a potential interaction between azithromycine and warfarin in patients stabilized on warfarin. Pharmacotherapy 2000 Sep;20(9 1055-9. Call KL, Anderson HG Jr, Jones AD.