Telmisartan interaction

Drugs that may interact with telmisartan include digoxin and warfarin. 

GRAPEFRUIT JUICE CANDESARTAN, EPROSARTAN, TELMISARTAN, VALSARTAN Likely interaction. Clinical significance is uncertain and not confirmed by scientific testing These angiotensin II receptor blockers have low bioavailability, attributed to P-gp, which is inhibited by grapefruit juice. Thus t bioavailability is likely Be aware... 

Indometacin may attenuate the antihypertensive effect of losar-tan, valsartan, or other angiotensin II receptor antagonists. However, low-dose aspirin does not appear to alter the antihypertensive effect of losartan. No clinically relevant pharmacokinetic interactions occur between telmisartan and ibuprofen or paracetamol (acetaminophen), or between valsartan and indometacin. The combination of an NSAID and angiotensin II receptor antagonist can increase the risk of renal impairment and hyperkalaemia. 

No significant pharmacokinetic interactions occur between nifedipine and candesartan or irbesartan, or between amlodipine and telmisartan or valsartan. Calcium-channel blockers have been given safely with eprosartan or irbesartan. 

Symptomatic hypotension may occur when an angiotensin II receptor antagonist is started in patients taking high-dose diuretics. Potassium levels may be either increased, decreased or not affected. No clinically relevant pharmacokinetic interactions appear to occur between candesartan, eprosartan, irbesartan, losartan, telmisartan or valsartan and hydrochlorothiazide, although the bioavailability of hydrochlorothiazide may be modestly reduced. Similarly, there is no clinically significant pharmacokinetic interaction between valsartan and furosemide. 

In a randomised, crossover study in 13 healthy subjects, telmisartan 160 mg daily was given with hydrochlorothiazide 25 mg daily for 7 days. There was no difference in AUC and maximum plasma concentrations of either drug compared with when they were given alone. Similarly, no pharmacokinetic interactions were found between irbesartan and hydrochlorothiazide. ... 

The available pharmacokinetic and pharmacodynamic studies showing that the angiotensin II receptor antagonists (candesartan, eprosartan, irbe-sartan, losartan, telmisartan, valsartan) do not interact with warfarin, and the lack of any published evidence to the contrary, suggest that no warfarin dose adjustments should be needed if these drugs are used. 

It has been suggested that telmisartan may have caused digoxin to be more rapidly absorbed. An in vitro study found that candesartan and losartan do not appear to inhibit P-glycoprotein-mediated transcellular transport. Therefore interactions resulting in reduced digoxin renal excretion are unlikely. ... 

Irbesartan and telmisartan appear not to alter the pharmacokinetics of simvastatin, fluvastatin does not alter the pharmacokinetics of losartan or its active metabolite, and ohnesartan appears not to interact with pravastatin. 

A study in 12 healthy subjects found that irbesartan 300 mg had no significant effect on the pharmacokinetics of a single 50-mg dose of simvastatin, or its metabolite simvastatin acid, and the combination was well-tolerated. No clinically relevant interaction was noted when telmisartan was given with simvastatin. ... 

Drug-drug interactions Mycophenolate mofetil In a pharmacokinetic study of telmisartan, valsartan, and candesartan in combination with mycophenolate mofetil in renal transplant patients, telmisartan increased the elimination of mycophenolic acid there was no interaction with valsartan or candesartan [57 ]. It was suggested that this was due to activation by... 

Drug-Drug Interaction Lithium. Telmisartan 40 mg per day was added into the antihypertensive regimen of a 52-year-old schizophrenic woman who had been on lithium 900 mg and haloperidol 20 mg per day. Her lithium level increased to 2.6 meq/L from a range of between 0.83 meq/L and 1.02 meq/L prior to the introduction of telmisartan urea and creatinine increased from normal baseline values to 76 mg/dL and 4.6 mg/dL, respectively, and potassium level was 7.0 mmol/L. Following haemodialysis, her laboratory results retiuned to normal, symptoms abated and lithium was replaced with valproic acid [18 ]. The exact mechanism of this interaction is not known however, it is thought that activation of ATI results in increasing sodium reabsorption at the proximal convoluted tubules which subsequently results in reduction in aldosterone secretion. This ultimately causes hyperkalemia and hyponatraemia. Sodium depletion may cause increase in lithium reabsorption from the proximal convoluted tubules. 

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