Mistel Drug Interactions

Digoxin: When Telmisartan was co-administered 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 under-digitalization.
Lithium: Reversible increases in serum lithium concentrations and toxicity have been reported during concomitant administration of lithium with angiotensin converting enzyme inhibitors. Cases have also been reported with angiotensin II receptor antagonists including Telmisartan tablets. Therefore, serum lithium level monitoring is advisable during concomitant use.
Ramipril and Ramiprilat: Co-administration of Telmisartan 80 mg once daily and Ramipril 10 mg once daily to healthy subjects increases steady-state Cmax and AUC of Ramipril 2.3 and 2.1 fold, respectively, and Cmax and AUC of Ramiprilat 2.4 and 1.5 fold, respectively. In contrast, Cmax and AUC of Telmisartan decrease by 31% and 16%, respectively. When co-administering Telmisartan and Ramipril, the response may be greater because of the possibly additive pharmacodynamic effects of the combined drugs, and also because of the increased exposure to Ramipril and Ramiprilat in the presence of Telmisartan.
Warfarin: Telmisartan administered for 10 days slightly decreased the mean warfarin trough plasma concentrations; this decrease did not result in a change in International Normalized Ratio (INR).
Other Drugs: Co-administration of Telmisartan did not result in a clinically significant interaction with acetaminophen, amlodipine, glibenclamide, simvastatin, hydrochlorothiazide or ibuprofen. Telmisartan is not metabolized by the cytochrome P450 system and had no effects in vitro on cytochrome P450 enzymes, except for some inhibition of CYP2C19. Telmisartan 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.