Plasma concentrations of ramipril and the active metabolite, ramiprilat, may be increased, while plasma concentrations of telmisartan may be reduced. When coadministered, the hypotensive response may be increased because of possible additive pharmacodynamic effects, and because of the increased exposure to ramipril and ramiprilat. Coadministration of telmisartan and an ACE inhibitor is not recommended.
May increase plasma levels of digoxin, increasing the risk of toxicity. Monitor digoxin concentrations when starting, stopping, or changing telmisartan dose. Adjust the digoxin dose as needed.
Plasma concentrations may be increased by telmisartan, resulting in an increase in the pharmacologic effects and adverse reactions of lithium. Monitor lithium serum concentrations and observe the clinical response of the patient. Adjust the lithium dose as needed.
Potassium-sparing diuretics (eg, amiloride)
The risk of hyperkalemia may be increased when a potassium-sparing diuretic is coadministered with telmisartan. Closely monitor serum potassium concentrations. Adjust treatment as needed.