Warfarin should usually be started at a dose of 5 mg per day.A 10-mg dose more frequently results in a supratherapeutic international normalized ratio (INR).
During the study, the dosage of warfarin was adjusted to maintain an INR of 2 to 3 in most patients. Similarly, if a patient is controlled on warfarin but a provider begins an INR-increasing antibiotic, the patient’s INR could rise above the therapeutic range.
Clinical observations with the amiodarone/warfarin interaction. 2008 May 15;65(10):947-52. doi: 10.2146/ajhp060415.Santos PC, Soares RA, Strunz CM, Grinberg M, Ferreira JF, Cesar LA, Scanavacca M, Krieger JE, Pereira AC.J Manag Care Spec Pharm. Minor episodes of bleeding occurred in 12 percent of the study subjects.The authors conclude that the degree of interaction between amiodarone and warfarin is highly dependent on the maintenance dosage of amiodarone. If you do not receive an email within 10 minutes, your email address may not be registered, Patients were excluded from participation if they were taking other medications that could affect the INR or interact with either of these medications. 2017 Mar;15(3):446-453. doi: 10.1111/jth.13614. Managing this drug‐drug interaction (DDI) is challenging because of substantial interpatient variability in DDI magnitude. doi: 10.7759/cureus.8311.Colunga Biancatelli RM, Congedo V, Calvosa L, Ciacciarelli M, Polidoro A, Iuliano L.J Geriatr Cardiol. Renal function was estimated with creatinine clearance (CrCl). Epub 2018 Oct 22.
Amiodarone, a class III antiarrhythmic, has become the drug of choice for the management of supraventricular and ventricular arrhythmias. This information could inform warfarin dosage adjustment and monitoring and may have implications for the selection of oral anticoagulation agents in patients treated with amiodarone. Amiodarone (Cordarone, Pacerone) is considered one of the first-line antiarrhythmics for these conditions.2,3 Therefore, many patients will have an indication for concomitant warfarin and amiodarone therapy. There are a number of important drug interactions with amiodarone. COVID-19 is an emerging, rapidly evolving situation.
Amiodarone therapy was initiated in the hospital and titrated down to the standard dosage of 200 or 400 mg per day, based on the underlying cardiac pathology. 1 Although not currently approved by the FDA for the treatment of atrial fibrillation (AF), it has been used in the past for this condition. Elsevier Science Minor bleeding episodes occurred in five patients (12%). However, amiodarone does have complex interactions with multiple medications. Maintenance warfarin dose adjustments should be based on current INR results and trends and patient assessment of any missed doses, drug interactions, dietary intake or supplements, documentation of bleeding, or other changes that may affect the INR.
Warfarin is metabolized by the cytochrome (CYP) P450 enzyme system, specifically, CYPs 1A2, 3A4, and 2C9.
These results suggest that renal function is a novel factor that explains substantial variability in the warfarin‐amiodarone DDI. Amiodarone (Cordarone, Pacerone) is considered one of the first-line antiarrhythmics for these conditions.2,3 Therefore, many patients will have an indication for concomitant warfarin and amiodarone therapy. Patients were queried from an electronic health record database.
1 This resource takes a detailed look at some of the many amiodarone drug interactions that can occur and how to minimize problems.
The study is based on cephalexin and amiodarone hydrochloride (the active ingredients of Keflex and Amiodarone hydrochloride, respectively), and Keflex and Amiodarone hydrochloride (the brand names). Epub 2017 Feb 17.Lu Y, Won KA, Nelson BJ, Qi D, Rausch DJ, Asinger RW.Am J Health Syst Pharm.
Asking if any medication changes have occurred since the This information could inform warfarin dosage adjustment and monitoring and may have implications for the selection of oral anticoagulation agents in patients treated with amiodarone.