| Indication | For management of heart failure, angina pectoris, and mild to moderate hypertension and for secondary prevention of myocardial infarction (MI). |
| Pharmacodynamics | Bisoprolol is a competitive, cardioselective β1-adrenergic antagonist. Activation of β1-receptors (located mainly in the heart) by epinephrine increases heart rate and the blood pressure causing the heart to consume more oxygen. β1-adrenergic blocking agents such as bisopolol lower the heart rate and blood pressure and may be used to reduce workload on the heart and hence oxygen demands. They are routinely prescribed in patients with ischemic heart disease. In addition, β1-selective blockers prevent the release of renin, a hormone produced by the kidneys causes constriction of blood vessels. Bisoprolol is lipophilic and exhibits no intrinsic sympathomimetic activity (ISA) or membrane-stabilizing activity. |
| Mechanism of action | Bisoprolol selectively blocks catecholamine stimulation of β1-adrenergic receptors in the heart and vascular smooth muscle. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. At higher doses (e.g. 20 mg and greater) bisoprolol may competitively block β2-adrenergic receptors in bronchial and vascular smooth muscle causing bronchospasm and vasodilation. |
| Absorption | Well absorbed. Bioavailability > 80%. Absorption is not affected by food. Peak plasma concentrations occur within 2-4 hours. |
| Volume of distribution | Not Available |
| Protein binding | Binding to serum proteins is approximately 30% |
| Metabolism | Approximately 50% of the dose is metabolized primarily metabolized by CYP3A4 to inactive metabolites. In vitro studies have shown that bisoprolol is also metabolized by CYP2D6 though this does not appear to be clinically significant. Approximately half the administered dose is excreted in unchanged in urine. |
| Route of elimination | Eliminated equally by renal and non-renal pathways. Approximately 50% of the total orally administered dose is excreted unchanged in urine with the remainder appearing as inactive metabolites. Less than 2% of the dose is excreted in the feces. |
| Half life | 9-12 hours; prolonged in the elderly and those with decreased renal function |
| Clearance | Not Available |
| Toxicity | Oral, mouse: LD50 = 100 mg/kg; Skin, rabbit: LD50 = 200 mg/kg; Skin, rat: LD50 = 500 mg/kg. Symptoms of overdose include congestive heart failure (marked by sudden weight gain, swelling of the legs, feet, and ankles, fatigue, and shortness of breath), difficult or labored breathing, low blood pressure, low blood sugar, and slow heartbeat. |