TENORMIN (Generic name : Atenolol)

Description :
Tenormin, is one of the a type medication for anti anginal known as beta blocker.



Presentation :
Tab 50 mg and 100 mg



Action :
Atenolol is a beta blocker which is beta one selective (ie: acts preferentially on beta one adrenergic receptorin the heart).Selecivity decreases with increasing dose. Atenolol is without intrinsic sympathomimetic and membrane stabilizing activities and as with other beta blockers, atenolol has negative inotropic effects (therefore contraindicated in uncontrolled heart failure).
As with other beta blockers, the mode of action in the treatment of hypertension is unclear. It is probably the action of Tenormin in reducing cardiac rate and contractility which make it effective in eliminating or reducing the symptoms of patients with angina.
Tenormin is compatible with diuretics, other antihypertensive agents and antianginal agents



Interactions:
Combined use of beta blockers and calcium channel blockers with negative initropic effects such as verapamil, diltiazem, can lead to an exaggeration of these effect particularly in patients with impaired ventricular function and or siniatrial (SA) or atrio-ventricular (AV) conduction abnormalities. This may result in severe hypotension, bradycardia and cardiac failure.
Neither the beta blocker nor the calcium –channel beta blocker should be administered IV within 48 hours of discontinuing the other.
Concomitant therapy with dihydropyridines (eg: nifedipine) may increase the risk of hypertension and cardiac failure may occur in patien with latent cardiac insuffiency.
Digitalis glycosides, in association with beta blockers, may increase atrioventricular conduction time.
Beta blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the drugs are co-administered, the beta blocker should be withdrawal several days before discontinuing clonidine . If replacing clonidine by beta blocker therapy , the introduction of beta blockers should be delayed for several days after clonidine administration has stopped.
Caution must be exercised when prescribing a beta blocker with class 1 antiarrhythmic agents (eg disopyramide).
Caution must be exercised when using anaesthetic agents with tenormin. The anaesthetist should be informed and the choice of anaesthetic should be an agent with as little negative inotropic activity as possible.




Indication :
Hypertension, Angina pectoris, Cardia arrhytmias, Early and late intervention of myocardiac infarction.



Contraindications:
Tenormin, as with other beta blockers should not be used in patients with any of the following:
Hypersensitivity to the substance
Bradycardia
Cardiogenic shock
Hypotension
Metabolic acidosis
Severe peripheral arterial circulatory disturbance
Second or third degree heart block
Sick sinus syndrome
Untreated phaeochromocytoma
Uncontrolled heart failure



Precaution:
Tenormin, may be used in patients whose signs of heart failure have been controlled.
Caution must be exercised in patients whose cardiac reserve poor. It may increase the number and duration og angina attacks in patients with prinzmetal`s angina due to unopposed alpha-receptor – mediated coronary artery contriction must be exercised.
Tenormin will reduce heart rate , as a result of its pharmacological action. In the rare instances when a treated patient develops symptoms which may be attributable to a slow heart rate, the dose may be reduced.
Treatment should not be discontinuied abruptly in patients suffering from ischaemic heart diseases.
Tenormin may cause a more severe reaction to a variety of allergens, when given to patients with a history of anaphylactic reaction to such allergens.
Administrations of tenormin for longer periods to pregnant women in the management of mild to moderate hypertension has been associated with intra uterine growth retardation. The use of tenormin in women who are or may become pregnant requires that the anticipated benefit be weighed against the possible risks, particularly in the 1st and 2nd trimesters.



Dosage & Administrations
Adult:
Hypertension --> 50 mg – 100 mg daily given orally as a single daily dose. The effect will be fully estabilished after 1-2 weeks. A further reduction in blood pressure may be achieved by comining tenormin with with others antihypertensive agents.
Angina --> 100 mg daily as a single dose or 50 mg given twice daily.
Arrhytmias --> A suitable initial dose of 2,5mg IV over 2,5 minute period (1 mg/minute). This may be repeated at 5 minute interval until response is observed. Up to a maximum dosage of 10 mg. If tenormin is given by infusion (0,15mg/kg body weight) may be administered over 20 minute period. If required, the injection or infusion may be repeated every 12 hours.
Myocardiac Infarction --> Early intervention : for patients suitable for treatment with IV beta blockade and presenting within 12 hrs of the onset of chest pain, tenormin (atenolol) 5-10 mg should be given immediately by slow IV injection (1 mg/minute) followed by tenormin 50 mg orally 15 minute later.
Late intervention : After acute myocardial infarction who present a few days after suffering an acute myocardial infarction , an oral dose of tenomin 100 mg daily is recommended for long-term prophylaxis of myocardial infarction.

Elderly :
Dosage requirements may be reduced, especially in patients with impaired renal fuction.



Adverse reaction
Tenormin is well tolerated. In clinical studies, the undesired events reported are usually attributable to the pharmacological actions of tenormin (atenolol).
The following undesirable events have been reported :
Bradycardia, heart failure, postural hypotension, heart block.
Confusion, dizziness, headache, mood changes.
Dry mouth, GI disturbance
Purpura, thrombocytopenia
Alopecia, dry eyes, skin rashes
Paraesthesia
Bronchospasm
Visual disturbances

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