Drug Drug Interactions

No pharmacokinetic or pharmacodynamic drug interactions have been demonstrated between argatroban and aspirin (Clark et al., 1991), erythromycin (Tran et al., 1999), acetaminophen, digoxin, or lidocaine (Inglis et al., 2002). In practice, argatroban coadministered with these frequently used medications should require no dosage adjustments.

No pharmacokinetic interactions have been demonstrated between argatro-ban and warfarin (Brown and Hursting, 2002). DTIs as a class variably prolong the PT/INR—argatroban to a greater extent than bivalirudin and lepirudin (Warkentin et al., 2005)—and the concomitant use of argatroban and warfarin prolongs the PT/INR beyond that produced by warfarin alone (Hursting et al., 1999; Sheth et al., 2001). Cotherapy compared with warfarin monotherapy exerts no additional effect on vitamin K-dependent factor X levels (Sheth et al., 2001), and INRs >5 commonly occur in patients with HIT during argatroban/warfarin cotherapy (and argatroban monotherapy) without bleeding (Hursting et al., 2005). Hence, the previously established ("traditional") relationship between INR and bleeding risk is altered during combination therapy. Guidelines for monitoring the transition from argatroban to warfarin anticoagulation are presented in Section IV.

Argatroban and a variety of drugs have been evaluated for chemical or physical/visual compatibility at concentrations commonly used in practice. This is important for supporting their simultaneous administration via Y-site injection. Argatroban and eptifibatide or tirofiban are chemically and physically compatible (Patel and Hursting, 2005). Argatroban and abciximab (Patel and Hursting, 2005), fentanyl citrate, midazolam hydrochloride, morphine sulfate, dopamine hydro-chloride, dobutamine hydrochloride, phenylephrine hydrochloride, atropine sulfate, hydrocortisone sodium succinate, metoprolol tartrate, diphenhydramine hydrochloride, verapamil hydrochloride, norepinephrine bitartrate, diltiazem hydrochloride (Hartman et al., 2002), fenoldopam mesylate, lidocaine hydrochloride, milrinone lactate, nitroglycerin, or vasopressin (Honikso et al., 2004) are physically/visually compatible; their chemical stability remains to be established. Argatroban and amiodarone should not be infused through the same iv line because precipitation may occur (Honikso et al., 2004).

0 0

Post a comment