Telmez HCT Drug Interactions

Lithium: Reversible increases in serum lithium concentrations and toxicity have been reported during concomitant administration of lithium with angiotensin converting enzyme inhibitors. Rare cases have also been reported with angiotensin II receptor antagonists (including Telmisartan and Hydrochlorothiazide). Co-administration of lithium and Telmisartan and Hydrochlorothiazide is not recommended. If this combination proves essential, careful monitoring of serum lithium level is recommended during concomitant use.
Medicinal products associated with potassium loss and hypokalemia (e.g. other kaliuretic diuretics, laxatives, corticosteroids, ACTH, amphotericin, carbenoxolone, penicillin G sodium, salicylic acid and derivatives): If these substances are to be prescribed with the hydrochlorothiazide-telmisartan combination, monitoring of potassium plasma levels is advised. These medicinal products may potentiate the effect of hydrochlorothiazide on serum potassium.
Medicinal products that may increase potassium levels or induce hyperkalemia (e.g. ACE inhibitors, potassium-sparing diuretics, and potassium supplements, salt substitutes containing potassium, cyclosporin or other medicinal products such as heparin sodium): If these medicinal products are to be prescribed with the hydrochlorothiazide-telmisartan combination, monitoring of potassium plasma levels is advised. Based on the experience with the use of other medicinal products that blunt the renin-angiotensin system, concomitant use of the previously mentioned medicinal products may lead to increases in serum potassium and is, therefore, not recommended.
Medicinal products affected by serum potassium disturbances: Periodic monitoring of serum potassium and ECG is recommended when Telmisartan and Hydrochlorothiazide is administered with medicinal products affected by serum potassium disturbances (e.g. digitalis glycosides, antiarrhythmics) and the following torsades de pointes inducing medicinal products (which include some antiarrhythmics), hypokalemia being a predisposing factor to torsades de pointes.
Class Ia antiarrythmics (e.g. quinidine, hydroquinidine, disopyramide).
Class III antiarrythmics (e.g. amiodarone, sotalol, dofetilide, ibutilide).
Some antipsychotics (e.g. thioridazine, chlorpromazine, levomepromazine, trifluoperazine, cyamemazine, sulpiride, sultopride, amisulpride, tiapride, pimozide, haloperidol, droperidol).
Others (e.g. bepridil, cisapride, diphemanil, erythromycin IV, halofantrin, mizolastin, pentamidine, sparfloxacine, terfenadine, vincamine IV).
Digitalis glycosides: Thiazide-induced hypokalemia or hypomagnesemia favours the onset of digitalis-induced arrhythmia.
Digoxin: When initiating, adjusting, and discontinuing telmisartan, monitor digoxin levels in order to maintain levels within the therapeutic range.
Other antihypertensive agents: Telmisartan may increase the hypotensive effect of other antihypertensive agents.
Clinical trial data has shown that dual blockade of the renin-angiotensin-aldosterone-system (RAAS) through the combined use of ACE-inhibitors, angiotensin II receptor blockers or aliskiren is associated with a higher frequency of adverse events such as hypotension, hyperkalemia and decreased renal function (including acute renal failure) compared to the use of a single RAAS-acting agent.
Antidiabetic medicinal products (oral agents and insulin): Dosage adjustment of the antidiabetic medicinal products may be required.
Metformin: Metformin should be used with precaution: risk of lactic acidosis induced by a possible functional renal failure linked to hydrochlorothiazide.
Cholestyramine and colestipol resins: Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins.
Non-steroidal anti-inflammatory medicinal products: NSAIDs (i.e. acetylsalicylic acid at anti-inflammatory dosage regimens, COX-2 inhibitors and non-selective NSAIDs) may reduce the diuretic, natriuretic and antihypertensive effects of thiazide diuretics and the antihypertensive effects of angiotensin II receptor antagonists.
The combination should be administered with caution, especially in the elderly. Patients should be adequately hydrated and consideration should be given to monitoring of renal function after initiation of concomitant therapy and periodically thereafter.
Pressor amines (e.g. noradrenaline): The effect of pressor amines may be decreased.
Nondepolarizing skeletal muscle relaxants (e.g. tubocurarine): The effect of nondepolarizing skeletal muscle relaxants may be potentiated by hydrochlorothiazide.
Medicinal products used in the treatment for gout (e.g. probenecid, sulfinpyrazone and allopurinol): Dosage adjustment of uricosuric medications may be necessary as hydrochlorothiazide may raise the level of serum uric acid. Increase in dosage of probenecid or sulfinpyrazone may be necessary. Co-administration of thiazide may increase the incidence of hypersensitivity reactions of allopurinol.
Calcium salts: Thiazide diuretics may increase serum calcium levels due to the decreased excretion. If calcium supplements or calcium sparing medicinal products (e.g. vitamin D therapy) must be prescribed, serum calcium levels should be monitored and calcium dosage adjusted accordingly.
Beta-blockers and diazoxide: The hyperglycemic effect of beta-blockers and diazoxide may be enhanced by thiazides.
Anticholinergic agents (e.g. atropine, biperiden): May increase the bioavailability of thiazide-type diuretics by decreasing gastrointestinal motility and stomach emptying rate.
Amantadine: Thiazides may increase the risk of adverse effects caused by amantadine.
Cytotoxic agents (e.g. cyclophosphamide, methotrexate): Thiazides may reduce the renal excretion of cytotoxic medicinal products and potentiate their myelosuppressive effects.
Based on their pharmacological properties it can be expected that the following medicinal products may potentiate the hypotensive effects of all antihypertensives including telmisartan: Baclofen, amifostine.
Furthermore, orthostatic hypotension may be aggravated by alcohol, barbiturates, narcotics or antidepressants.