Digoxin: When telmisartan was coadministered with digoxin, median increases in digoxin peak plasma
concentration (49%) and in trough concentration (20%) were observed. It is, therefore, recommended that digoxin
levels be monitored when initiating, adjusting, and discontinuing telmisartan to avoid possible over- or
Warfarin: Micardis administered for 10 days slightly decreased the mean warfarin
trough plasma concentration; this decrease did not result in a change in International Normalized Ratio (INR).
Other Drugs: Coadministration of telmisartan did not result in a clinically significant
interaction with acetaminophen, amlodipine, glibenclamide, simvastatin, hydrochlorothiazide or ibuprofen. Micardis
is not metabolized by the cytochrome P450 system and had no effects in vitro on cytochrome P450 enzymes, except for
some inhibition of CYP2C19. Micardis is not expected to interact with drugs that inhibit cytochrome P450 enzymes;
it is also not expected to interact with drugs metabolized by cytochrome P450 enzymes, except for possible inhibition
of the metabolism of drugs metabolized by CYP2C19.
Hydrochlorothiazide: When administered concurrently, the following drugs may interact
with thiazide diuretics: Alcohol, barbiturates, or narcotics: Potentiation of orthostatic hypotension may occur.
Antidiabetic drugs (oral agents and insulin): Dosage adjustment of the antidiabetic drug may be
Other antihypertensive drugs: Additive effect or potentiation.
Cholestyramine and colestipol resins: Absorption of hydrochlorothiazide is impaired in the presence
of anionic exchange resins. Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide
and reduce its absorption from the gastrointestinal tract by up to 85% and 43%, respectively.
Corticosteroids, ACTH: Intensified electrolyte depletion, particularly hypokalemia.
Pressor amines (e.g., norepinephrine): Possible decreased response to pressure amines
but not sufficient to preclude their use.
Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine): Possible increased
responsiveness to the muscle relaxant.
Lithium: Should not generally be given with diuretics. Diuretic agents reduce the renal
clearance of lithium and add a high risk of lithium toxicity. Refer to the package insert for lithium preparations
before use of such preparations with MICARDIS HCT.
Non-steroidal anti-inflammatory drugs: In some patients, the administration of a
non-steroidal antiinflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop,
potassium-sparing and thiazide diuretics. Therefore, when MICARDIS HCT and non-steroidal anti-inflammatory agents are
used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is