Mistacor AM Drug Interactions

No interactions between the two components of this fixed dose combinations have been observed in clinical studies.
Interactions common to the combination: No drug interaction studies have been performed with Telmisartan + Amlodipine besilate and other medicinal products.
Concomitant use to be taken into account: Other antihypertensive agents: The blood pressure lowering effect of Telmisartan + Amlodipine besilate can be increased by concomitant use of other antihypertensive medicinal products.
Agents with blood pressure lowering potential: Based on their pharmacological properties it can be expected that the following medicinal products may potentiate the hypotensive effects of all antihypertensives including Telmisartan + Amlodipine besilate, e.g. baclofen, amifostine. Furthermore, orthostotic hypotension may be aggravated by alcohol, barbiturates, narcotics, or antidepressants.
Corticosteroids (systemic route): Reduction of the antihypertensive effect.
Interactions linked to telmisartan: Telmisartan may increase the hypotensive effect of other antihypertensive agents.
Co-administration of telmisartan did not result in a clinically significant interaction with digoxin, warfarin, hydrochlorothioazide, glibenclamide, ibuprofen, paracetamol, simvastatin and amlodipine. For digoxin, a 20% increase in median plasma digoxin trough concentration has been observed (39% in a single case), monitoring of plasma digoxin levels should be considered.
In one study the co-administration of telmisartan and ramipril led to an increase of up to 2.5 fold in the AUC_0-24 and C_max of ramipril and ramiprilat. The clinical relevance of this observation is not known.
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. Therefore, serum lithium level monitoring is advisable during concomitant use.
Treatment with NSAIDs (i.e. ASA at anti-inflammatory dosage regimens, COX-2 inhibitors and non-selective NSAIDs) is associated with the potential for acute renal insufficiency in patients who are dehydrated. Compounds acting on the Renin-Angiotensin-System like telmisartan may have synergistic effects.
Patients receiving NSAIDs and telmisartan should be adequately hydrated and be monitored for renal function at the beginning of combined treatment.
A reduced effect of antihypertensive drugs like telmisartan by inhibition of vasodilating prostaglandins has been reported during combined treatment with NSAIDs.
Interactions linked to amlodipine: Concomitant use requiring caution: Grapefruit and grapefruit juice: Administration of Telmisartan + Amlodipine besilate with grapefruit juice is not recommended since bioavailability may be increased in certain patients resulting in increased blood pressure lowering effects.
CYP3A4 inhibitors: A study in elderly patients has shown that diltiazem inhibits the metabolism of amlodipine, probably via CYP3A4 (plasma concentration increases by approximately 50% and the effect of amlodipine is increased).
The possibility that more potent inhibitors of CYP3A4 (i.e. ketoconozole, itraconazole, ritonavir) may increase the plasma concentration of amlodipine to a greater extent than diltiazem cannot be excluded.
CYP3A4 inducers (anticonvulsant agents [e.g. carbamazepine, phenobarbital, phenytoin, phosphenytoin, primidone], rifampicin, Hypericum perforatum): Co-administration may lead to reduced plasma concentrations of amlodipine. Clinical monitoring is indicated, with possible dosage adjustment of amlodipine during the treatment with the inducer and after its withdrawal.
Concomitant use to be taken into account: Simvastatin: Co-administration of multiple doses of amlodipine with simvastatin 80 mg resulted in on increase in exposure to simvastatin up to 77% compared to simvastatin alone. Therefore, limit the dose of simvastatin in patients on amlodipine to 20 mg daily.
Immunosuppressants: Amlodipine may increase the systemic exposure of ciclosporin or tacrolimus when co-administered. Frequent monitoring of trough blood levels of ciclosporin and tacrolimus and dose adjustment when appropriate is recommended.
Others: In monotherapy, amlodipine has been safely administered with thiazide diuretics, beta blockers, ACE inhibitors, long acting nitrates, sublingual nitroglycerin, non-steroidal anti-inflammatory medicines, antibiotics and oral hypoglycaemic medicines. When amlodipine and sildenafil were used in combination, each agent independently exerted its own blood pressure lowering effect.
Additional information: Concomitant administration of 240 mL of grapefruit juice with a single oral dose of 10 mg amlodipine in 20 healthy volunteers did not show a significant effect on the pharmacokinetic properties of amlodipine.
Co-administration of amlodipine with cimetidine had no significant effect on the pharmacokinetics of amlodipine. Co-administration of amlodipine with atorvastatin, digoxin or warfarin had no significant effect on the pharmacokinetics or pharmacodynamics of these agents.