Mode of Action
Bisoprolol fumarate/hydrochlorothiazide is a fixed-combination tablet that combines a Beta adrenergic receptor blocker, bisoprolol fumarate, and a thiazide diuretic, hydrochlorothiazide.
Bisoprolol fumarate, a cardioselective inhibitor of beta(1)-adrenoceptor, has no significant intrinsic sympathomimetic activity or membrane stabilizing activity in its therapeutic dosage; exhibits beta(2)-adrenoceptors inhibition and negative chronotropic effect.
Hydrochlorothiazide is a thiazide diuretic that inhibits Na reabsorption in distal renal tubules resulting in increased excretion of Na+ and water, also K+ and H+ ions.
Precaution
Bronchospastic disease, hyperthyroidism, peripheral vascular disease, undergoing anaesthesia. Monitor blood glucose regularly. May mask symptoms of hypoglycaemia. Elderly. Gradual withdrawal is advised.
Lactation: excreted in breast milk, use caution
Side Effect
1-10%
Bisoprolol fumarate
Arthralgia (3%), asthenia (2%), cough (3%), diarrhea (4%), dizziness (10%), dry mouth (1%), dyspnea (2%), fatigue (8%), headache (11%), hypoaesthesia (2%), insomnia (3%), nausea (2%), peripheral edema (4%), pharyngitis (2%), rhinitis (4%), sinusitis (2%), upper respiratory infection (5%), vomiting (2% )
Hydrochlorothiazide
Anorexia,Epigastric distress,Hypokalemia,Hypotension,Orthostatic hypotension,Phototoxicity
Frequency Not Defined
Bisoprolol fumarate
Aggravate CHF, cold extremeties, decrease HDL, depression, hypotension, increase bronchospasm, increase triglycerides, mask symptoms of hypoglycemia, muscle & joint pain
Hydrochlorothiazide
Agranulocytosis, anaphylaxis, anemia, Confusion, erythema multiforme skin reactions including Stevens-Johnson syndrome
Exfoliative dermatitis including toxic epidermal necrolysis, Hypomagnesemia, hyponatremia, hypochloremia, dizziness, fatigue, headache, hypercalcemia, hyperuricemia, hyperglycemia, hyperlipidemia, hypercholesterolemia, muscle weakness or cramps, nausea, purpura, rash, vertigo, vomiting
Potentially Fatal: AV block, bradycardia. Rare but may occur in patients with preexisting cardiac disease. Includes severe bronchospasm, hypoglycaemia, hypotension, orthostatic hypotension, bradyarrhythmias. 'Rebound phenomenon' leading to unstable angina or MI on sudden withdrawal.
Interaction
Bisoprolol : May potentiate AV conduction time and may increase negative inotropic effect w/ class I antiarrhythmic drugs (e.g. quinidine, disopyramide, propafenone). Concomitant catecholamine-depleting drugs (e.g. reserpine, guanethidine) may produce excessive sympathetic activity. May exacerbate rebound HTN upon discontinuance of clonidine treatment. Increased risk of bradycardia w/ digitalis glycosides. Reduced hypotensive effect w/ NSAIDs.
Hydrochlorothiazide: Increases toxicity of lithium. May potentiate orthostatic hypotension w/ barbiturates and narcotics. Enhanced neuromuscular blocking action of competitive neuromuscular blockers (e.g. atracurium). Increased hypokalaemic effect w/ corticosteroids, corticotropin, ?2 agonists (e.g. salbutamol). Additive effect w/ other antihypertensives. Potentiation of orthostatic hypotension w/ barbiturates or opioids. Reduced antihypertensive effect by drugs that cause fluid retention (e.g. corticosteroids, NSAIDs, carbenoxolone). Enhanced nephrotoxicity of NSAIDs. Reduced therapeutic effect of antidiabetics.