Olmetec Plus Drug Interactions

Effects of Other Medicinal Products on Olmetec Plus: Medicinal Products Affecting Potassium Levels: The potassium-depleting effect of hydrochlorothiazide (see Precautions) may be potentiated by the co-administration of other medicinal products associated with potassium loss and hypokalaemia (eg, other kaliuretic diuretics, laxatives, corticosteroids, ACTH, amphotericin, carbenoxolone, penicillin G sodium or salicylic acid derivatives).
Conversely, based on experience with the use of other drugs that affect the renin angiotensin system, concomitant use of potassium-sparing diuretics, potassium supplements, salt substitutes containing potassium or other drugs that may increase serum potassium levels (eg, heparin) may lead to increases in serum potassium (see Precautions).
If drugs which affect potassium levels are to be prescribed in combination with Olmetec Plus, monitoring of potassium plasma levels is advised.
Other Antihypertensive Agents: The blood pressure lowering effect of Olmetec Plus can be increased by concomitant use of other antihypertensive medications.
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): The administration of a NSAIDs may reduce the diuretic, natriuretic and antihypertensive effects of thiazide diuretics in some patients. In elderly patients and patients who may be dehydrated, there is a risk of acute renal failure; therefore, monitoring of renal function at the initiation of treatment is recommended.
Alcohol, Barbiturates, Narcotics or Antidepressants: Potentiation of orthostatic hypotension may occur.
Baclofen, Amifostine: Potentiation of antihypertensive effect may occur.
Cholestyramine and Colestipol Resins: Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins.
Anticholinergic Agents (eg, Atropine, Biperiden): Increased bioavailability of thiazide-type diuretics by decreasing gastrointestinal motility and stomach emptying rate.
Effects of Olmetec Plus on Other Medicinal Products: 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 antagonists. In addition, renal clearance of lithium is reduced by thiazides and consequently, the risk of lithium toxicity may be increased. Therefore, use of Olmetec Plus and lithium in combination is not recommended (see Precautions). If use of the combination proves necessary, careful monitoring of serum lithium levels is recommended.
Medicinal Products Affected by Serum Potassium Disturbances: Periodic monitoring of serum potassium and ECG is recommended when Olmetec Plus is administered with drugs affected by serum potassium disturbances (eg, digitalis glycosides and antiarrhythmics) and with the following Torsades de pointes-inducing medicinal products, hypokalaemia being a predisposing factor to Torsade de pointes: Class IA antiarrythmics (eg, quinidine, hydroquinidine, disopyramide).
Class III antiarrythmics (eg, amiodarone, sotalol, dofetilide, ibutilide).
Some antipsychotics (eg, thioridazine, chlorpromazine, levomepromazine, trifluoperazine, cyamemazine, sulpiride, sultopride, amisulpride, tiapride, pimozide, haloperidol, droperidol).
Others (eg, bepridil, cisapride, diphemanil, erythromycin IV, halofantrin, mizolastin, pentamidine, sparfloxacin, terfenadine, vincamine IV).
Digitalis Glycosides: Thiazide-induced hypokalaemia or hypomagnesaemia may favour the onset of digitalis-induced cardiac arrhythmias.
Antidiabetic Drugs (Oral Agents and Insulin): The treatment with a thiazide may influence the glucose tolerance. Dosage adjustment of the antidiabetic drug may be required (see Precautions).
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 hyperglyeaemic effect of β-blockers and diazoxide may be enhanced by thiazides.
Pressor Amines (eg, Noradrenaline): The effect of pressor amines may be decreased.
Nondepolarizing Skeletal Muscle Relaxants (eg, Tubocurarine): The effect of nondepolarizing skeletal muscle relaxants may be potentiated by hydrochlorothiazide.
Medicinal Products Used in the Treatment of Gout (Probenecid, Sulfinpyrazone and Allopurinol): Dosage adjustment of uricosuric medications may be necessary since hydrochlorothlazlde may raise the level of serum uric acid. Increased dosage of probenecid or sulfinpyrazone may be necessary. Co-administration of a thiazide may increase the incidence of hypersensitivity reactions to allopurinol.
Calcium Salts: Thiazide diuretics may increase serum calcium levels due to decreased excretion (see Precautions). If calcium supplements must be prescribed, serum calcium levels should be monitored and calcium dosage adjusted accordingly.
Amantadine: Thiazides may increase the risk of adverse effects caused by amantadine.
Cytotoxic Agents (eg, Cyclophosphamide, Methotrexate): Thiazides may reduce the renal excretion of cytotoxic drugs and potentiate the myelosuppressive effects.
Additional Information: Concomitant administration of olmesartan medoxomil and hydrochlorothiazide had no clinically-relevant effects on the pharmacokinetics of either component in healthy subjects.
Olmesartan medoxomil had no significant effect on the pharmacokinetics or pharmacodynamics of warfarin or the pharmacokinetics of digoxin. Co-administration 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 P-450 enzymes 1A1/2, 2A6, 2C8/9, 2C19, 2D6, 2E1 and 3M in vitro, and had no or minimal inducing effects on rat cytochrome P-450 activities. No clinically relevant interactions between olmesartan and drugs metabolised by the above cytochrome P-450 enzymes are expected.