Urosin

Atenolol.

Pharmacology: Atenolol is a β₁-selective (cardioselective) adrenergic receptor-blocking agent without membrane-stabilising and intrinsic sympathomimetic (partial agonist) activities.
The action of atenolol has been demonstrated by: Reduction in resting and exercise heart rate and cardiac output; reduction in systolic and diastolic blood pressure at rest and on exercise; inhibition of isoproterenol-induced tachycardia; and reduction in reflex orthostatic tachycardia.
Pharmacokinetics: Atenolol is rapidly but incompletely absorbed from the gastrointestinal tract. 40-50% are excreted in the urine unchanged and the rest are excreted in the feces mostly as unabsorbed drug. In healthy adults, peak plasma of 1-2 mcg/mL is achieved at 2-4 hrs after 200-mg oral administration. Its plasma half-life is 6-7 hrs. It is well distributed in most tissues except in brain and CSF. Atenolol crosses the placenta and diffuses to breast milk. About 5-15% are bound to plasma proteins.

Hypertension, angina pectoris.

Adults: Hypertension: 50-100 mg/day alone or in conjunction with other antihypertensive agents. The full effects of this dosage will usually be seen within 1-2 weeks.
Angina Pectoris: 50-100 mg once a day or in divided doses.
Increasing the dosage >100 mg is unlikely to produce more beneficial effects.
To be dispensed on physician's prescription.

Excessive bradycardia may be countered by atropine 1-2 mg IV, followed if necessary, by a bolus of glucagon 10 mg IV.
If required this may be repeated or followed by an IV infusion of glucagon 1-10 mg/hr depending on response.
If no response to glucagon or glucagon is unavailable, dobutamine 2.5-10 mcg/kg/min by an IV infusion may be given.
Any risk of hypotension occurring followed the use of β-adrenoceptor agonists will be reduced by the use of the more selective agents, eg dobutamine.

Patients with sinus bradycardia, heart block greater than first degree, cardiogenic shock and overt cardiac failure. Patients with asthma or a history of obstructive airway diseases.

Urosin should be given to patients with cardiac failure only when they are fully digitalised and should be done with great caution.
Urosin should be used with caution in patients with bronchospastic disease who do not respond to, or not tolerate with other antihypertensive treatment.
Urosin may mask the symptoms of hyperthyroidism and hypoglycemia and therefore, should be used with caution in these patients.
Use in pregnancy & lactation: Atenolol crosses the placental barrier and appears in cord blood. No studies have been performed on the use of atenolol in the 1st trimester and the possibility of foetal injury cannot be excluded.
Atenolol has been used under close supervision for the treatment of hypertension in the 3rd trimester. Administration of atenolol for longer period to pregnant women in the management of mild to moderate hypertension has been associated with intrauterine growth retardation. The use of atenolol in women who are, or may are, or may become pregnant, requires that the anticipated benefit be weighed against the possible risks, particularly in the 1st and 2nd trimesters.
There is significant accumulation of atenolol in breast milk. Caution should be exercised when atenolol is administered to a nursing mother.

Atenolol crosses the placental barrier and appears in cord blood. No studies have been performed on the use of atenolol in the 1st trimester and the possibility of foetal injury cannot be excluded.
Atenolol has been used under close supervision for the treatment of hypertension in the 3rd trimester. Administration of atenolol for longer period to pregnant women in the management of mild to moderate hypertension has been associated with intrauterine growth retardation. The use of atenolol in women who are, or may are, or may become pregnant, requires that the anticipated benefit be weighed against the possible risks, particularly in the 1st and 2nd trimesters.
There is significant accumulation of atenolol in breast milk. Caution should be exercised when atenolol is administered to a nursing mother.

Bradycardia, cold extremities, postural hypotension, dizziness, vertigo, nausea, diarrhoea, fatigue, skin rash and dry eyes.

The effects of salbutamol and isoprenaline on the bronchi are not impaired by atenolol. Atenolol can therefore be used in patients with obstructive airway diseases provided appropriate care is taken.
Where ventricular function is impaired, β-blockers and calcium antagonists of the verapamil type should be combined with care. Such combinations must be avoided in conduction disorders.
Care is needed when β-blockers are combined with class I antiarrhythmic agents, eg disopyramide. Care is also required when a change is made from clonidine to atenolol. If clonidine is given together with a β-blocker and treatment is discontinued, the β-blocker should be discontinued a few days before the gradual withdrawal of clonidine.
It is not advisable to discontinue a β-blocker before anaesthesia. Certain reactions during anaesthesia are altered by β-blockade. The anaesthetist must therefore be informed if a patient being treated with atenolol has to have a general anaesthetic. Vagal stimulation can be counteracted by atropine 1-2 mg IV.
In some circumstances, atenolol can potentiate the hypoglycaemic effects of insulin.

Store at temperatures below 30°C. Keep in a tight container. Protect from light and moisture.
Shelf-Life: 3 years.

Beta-Blockers

C07AB03 - atenolol ; Belongs to the class of selective beta-blocking agents. Used in the treatment of cardiovascular diseases.

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