OBJECT DRUGS

Angiotensin Receptor Blockers (ARBs):

• Azilsartan (Edarbi)
• Candesartan (Atacand)
• Eprosartan (Teveten)
• Irbesartan (Avapro)
• Losartan (Cozaar)
• Olmesartan (Benicar)
• Telmisartan (Micardis)
• Valsartan (Diovan)

PRECIPITANT DRUGS

• Tizanidine (Zanaflex)

Comment:

Patients on ACE inhibitors have developed severe hypotension after starting tizanidine therapy; theoretically, a similar reaction could occur if tizanidine were added to ARB therapy. Tizanidine, like the antihypertensive drug clonidine, is an alpha-2 adrenergic agonist, and may have additive hypotensive effects with ARBs.

Class 3: Assess Risk & Take Action if Necessary

• Consider Alternative:In patients taking an ARB, consider using muscle relaxants other than tizanidine (that are not alpha-2 adrenergic agonists). Some other muscle relaxants can also sometimes cause hypotension, but the risk is probably less than for tizanidine.
• Monitor: If tizanidine is used in a patient taking an ARB, monitor cardiovascular status carefully for evidence of an acute hypotensive reaction.