Alzor HCT Drug Interactions

Potential interactions related to both Olmesartan Medoxomil and hydrochlorothiazide: Concomitant use not recommended: Lithium: Reversible increases in serum lithium concentrations and toxicity have been reported during concomitant administration of lithium with angiotensin converting enzyme inhibitors and, rarely, with angiotensin II receptor antagonists. In addition, renal clearance of lithium is reduced by thiazides and consequently the risk of lithium toxicity may be increased. Therefore use of Olmesartan and Hydrochlorothiazide and lithium in combination is not recommended. If use of the combination proves necessary, careful monitoring of serum lithium levels is recommended.
Concomitant use requiring caution: Baclofen: Potentiation of antihypertensive effect may occur.
Non-steroidal anti-inflammatory medicinal products: NSAIDs (i.e. acetylsalicylic acid (> 3 g/day), COX-2 inhibitors and non-selective NSAIDs) may reduce the antihypertensive effect of thiazide diuretics and angiotensin II receptor antagonists.
In some patients with compromised renal function (e.g. dehydrated patients or elderly people with compromised renal function) the co-administration of angiotensin II receptor antagonists and agents that inhibit cyclo-oxygenase may result in further deterioration of renal function, including possible acute renal failure, which is usually reversible. Therefore, the combination should be administered with caution, especially in elderly people. Patients should be adequately hydrated and consideration should be given to monitoring of renal function after initiation of concomitant therapy and periodically thereafter.
Concomitant use to be taken into account: Amifostine: Potentiation of antihypertensive effect may occur.
Other antihypertensive agents: The blood pressure lowering effect of Olmesartan and Hydrochlorothiazide can be increased by concomitant use of other antihypertensive medicinal products.
Alcohol, barbiturates, narcotics or antidepressants: Potentiation of orthostatic hypotension may occur.
Potential interactions related to Olmesartan Medoxomil: Concomitant use not recommended: ACE-inhibitors, angiotensin II receptor blockers or aliskiren: 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, hyperkalaemia and decreased renal function (including acute renal failure) compared to the use of a single RAAS-acting agent.
Medicinal products affecting potassium levels: Based on experience with the use of other medicinal products that affect the renin-angiotensin system, concomitant use of potassium-sparing diuretics, potassium supplements, salt substitutes containing potassium or other medicinal products that may increase serum potassium levels (e.g. heparin, ACE inhibitors) may lead to increases in serum potassium. If medicinal products which affect potassium levels are to be prescribed in combination with Olmesartan and Hydrochlorothiazide combination, monitoring of potassium plasma levels is advised.
Bile acid sequestering agent colesevelam: Concurrent administration of the bile acid sequestering agent colesevelam hydrochloride reduces the systemic exposure and peak plasma concentration of olmesartan and reduces t½. Administration of Olmesartan medoxomil at least 4 hours prior to colesevelam hydrochloride decreased the drug interaction effect. Administering Olmesartan Medoxomil at least 4 hours before the colesevelam hydrochloride dose should be considered.
Additional information: After treatment with antacid (aluminium magnesium hydroxide), a modest reduction in bioavailability of Olmesartan was observed.
Olmesartan Medoxomil had no significant effect on the pharmacokinetics or pharmacodynamics of warfarin or the pharmacokinetics of digoxin.
Coadministration of Olmesartan Medoxomil with pravastatin had no clinically relevant effects on the pharmacokinetics of either component in healthy subjects.
Olmesartan had no clinically relevant inhibitory effects on human cytochrome P450 enzymes 1A1/2, 2A6, 2C8/9, 2C19, 2D6, 2E1 and 3A4 in vitro, and had no or minimal inducing effects on rat cytochrome P450 activities. No clinically relevant interactions between Olmesartan and medicinal products metabolised by the previously mentioned cytochrome P450 enzymes are expected.
Potential interactions related to hydrochlorothiazide: Concomitant use not recommended: Medicinal products affecting potassium levels: The potassium-depleting effect of hydrochlorothiazide may be potentiated by the coadministration of other medicinal products associated with potassium loss and hypokalaemia (e.g. other kaliuretic diuretics, laxatives, corticosteroids, ACTH, amphotericin, carbenoxolone, penicillin G sodium or salicylic acid derivatives). Such concomitant use is therefore not recommended.
Concomitant use requiring caution: Calcium salts: Thiazide diuretics may increase serum calcium levels due to decreased excretion. If calcium supplements must be prescribed, serum calcium levels should be monitored and calcium dosage adjusted accordingly.
Cholestyramine and colestipol resins: Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins.
Digitalis glycosides: Thiazide-induced hypokalaemia or hypomagnesaemia may favour the onset of digitalis-induced cardiac arrhythmias.
Medicinal products affected by serum potassium disturbances: Periodic monitoring of serum potassium and ECG is recommended when Olmesartan and Hydrochlorothiazide is administered with medicinal products affected by serum potassium disturbances (e.g. digitalis glycosides and antiarrhythmics) and with the following torsades de pointes (ventricular tachycardia)-inducing medicinal products (including some antiarrhythmics), hypokalaemia being a predisposing factor to torsades de pointes (ventricular tachycardia): Class la antiarrhythmics (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, sparfloxacin, terfenadine, vincamine IV).
Non-depolarizing skeletal muscle relaxants (e.g. tubocurarine): The effect of nondepolarizing skeletal muscle relaxants may be potentiated by hydrochlorothiazide.
Anticholinergic agents (e.g. atropine, biperiden): Increase of the bioavailability of thiazide-type diuretics by decreasing gastrointestinal motility and stomach emptying rate.
Antidiabetic medicinal products (oral agents and insulin): The treatment with a thiazide may influence the glucose tolerance. Dosage adjustment of the antidiabetic medicinal product may be required.
Metformin: Metformin should be used with caution because of the risk of lactic acidosis induced by possible functional renal failure linked to hydrochlorothiazide.
Beta-blockers and diazoxide: The hyperglycaemic effect of beta-blockers and diazoxide may be enhanced by thiazides.
Pressor amines (e.g. noradrenaline): The effect of pressor amines may be decreased.
Medicinal products used in the treatment of gout (e.g. probenecid, sulfinpyrazone and allopurinol): Dosage adjustment of uricosuric medicinal products may be necessary since hydrochlorothiazide may raise the level of serum uric acid. Increase in dosage of probenecid or sulfinpyrazone may be necessary. Coadministration of a thiazide may increase the incidence of hypersensitivity reactions to allopurinol.
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.
Salicylates: In case of high dosages of salicylates hydrochlorothiazide may enhance the toxic effect of the salicylates on the central nervous system.
Methyldopa: There have been isolated reports of haemolytic anaemia occurring with concomitant use of hydrochlorothiazide and methyldopa.
Cyclosporine: Concomitant treatment with cyclosporine may increase the risk of hyperuricaemia and gout-type complications.
Tetracyclines: Concomitant administration of tetracyclines and thiazides increases the risk of tetracycline-induced increase in urea. This interaction is probably not applicable to doxycycline.