Biselect 5
(Bisoprolol 5mg)

Drug Effects

Synonyms(It is also Known As)


Bisoprolol Fumarate,

Bisoprolol Hemifumarate

Class


Adrenergic Drugs

Sub Class


Beta-Adrenergic Receptor Antagonists

Chemical Formula


C18H31NO4

Iupac Name


[2-hydroxy-3-(4-{[2-(propan-2-yloxy)ethoxy]methyl}phenoxy)propyl](propan-2-yl)amine.

Usage


Bisoprolol is in a group of drugs called beta-blockers. Beta-blockers affect the heart and circulation (blood flow through arteries and veins). Bisoprolol is used to treat hypertension (high blood pressure).

Adverse Effect


Giddiness, headache, fatigue, bradycardia. Nausea, vomiting, diarrhoea or constipation, stomach discomfort, mild ocular stinging, photophobia, keratitis, decreased sexual ability. GI disturbances, dyspnoea, cold extremities, insomnia, hallucination, drowsiness and mood alterations. 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.

Mechanism 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.

Precaution


Bronchospastic disease, hyperthyroidism, peripheral vascular disease, undergoing anaesthesia. Monitor blood glucose regularly. May mask symptoms of hypoglycaemia. Elderly.

Gradual withdrawal is advised. Lactation.

Drug Interaction


Decreased effect with aluminum and calcium salts, barbiturates, cholestyramine, NSAIDs, ampicillin, rifampicin. May mask tachycardia from hypoglycaemia induced by insulin and oral hypoglycaemics. Effects of other antihypertensives may be intensified. Potentially Fatal: May increase the effects of drugs which slow AV conduction, α-blockers and α-adrenergic stimulants. Enhances the action of anaesthetic agents, clonidine, calcium antagonists, digitalis, hypoglycaemic agents and NSAIDs.

Pregnancy Category


Category C:

Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus. in 2nd & 3rd trimesters. Category D: There is positive evidence of human foetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).

Absorption


Well absorbed. Bioavailability > 80%. Absorption is not affected by food.

Peak plasma concentrations occur within 2-4 hours.

Distribution


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.

Elemination


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.

References


1. Bühring KU, Sailer H, Faro HP, Leopold G, Pabst J, Garbe A (1986). "Pharmacokinetics and metabolism of bisoprolol-14C in three animal species and in humans". J. Cardiovasc. Pharmacol. 8 Suppl 11: S218.

2. Leopold G (1986). "Balanced pharmacokinetics and metabolism of bisoprolol". J. Cardiovasc. Pharmacol. 8 Suppl 11: S16–20. 3. "Bisoprolol Official FDA information, side effects and uses.