Atenolol Tablets 50mg
Out of date information, search anotherSUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Atenolol Tablets 50mg
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Atenolol EP 50mg
3 PHARMACEUTICAL FORM
Tablet (Film Coated)
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Atenolol is a beta-adrenoceptor blocking drug indicated for: i) hypertension ii) angina pectoris iii) cardiac arrhythmias iv) myocardial infarction: early intervention in the acute phase
4.2 Posology and Method of Administration
Adults
Hypertension: Initially 50mg daily, either alone or in combination with a diuretic. The full effects of this dose will usually be seen within 1-2 weeks. If an optimal response is not achieved the dosage may be increased to 100mg daily. Doses higher than 100mg daily are unlikely to produce any further benefit.
Angina: 100mg once daily or 50mg twice daily.
Cardiac Arrhythmias: 50mg-100mg daily after having controlled the arrhythmias with intravenous Atenolol.
Myocardial infarction: 50mg orally 15 minutes after intravenous Atenolol, followed by a further 50mg orally 12 hours after intravenous Atenolol and then 12 hour later, 100mg orally daily. Discontinue Atenolol if bradycardia and/or hypotension requiring treatment or any other untoward effects occur.
Children
Dosage has not been established
Elderly
The elderly may require reduced dosage, particularly when renal function is impaired.
Renal Impairment
Atenolol is excreted via the kidneys and dosage should be adjusted as follows: Creatine Clearance
>35ml/min - Normal dosage.
15 - 35ml/min - Oral dose should be 50mg daily.
<15ml/min - Oral dose should be 25mg daily or 50mg on alternate
days.
Patients on dialysis should be given 50 mg orally after each dialysis with close monitoring as marked falls in blood pressure may occur.
4.3 Contraindications
Atenolol is contra-indicated for patients with: • hypersensitivity to atenolol • in patients with second or third degree heart block
• in patients with cardiogenic shock
• uncontrolled heart failure
• sick sinus syndrome (unless a pacemaker is in situ)
• hypotension
• untreated phaeochromocytoma
• severe peripheral circulatory disturbances
• bradycardia (<45-50bpm)
• after prolonged fasting
• in metabolic acidosis (eg in some diabetics)
4.4. Special warnings and precautions for use
Special care should be taken with patients whose cardiac reserve is poor. Beta-adrenoceptor blockers should be avoided in overt heart failure.
However, they may be used in patients whose signs of failure have been controlled.
One of the pharmacological actions of atenolol is to reduce heart rate. In the rare instances when symptoms may be attributable to the slow heart rate, the dose may be reduced.
Due to its negative effect on conduction time, caution must be exercised if given to patients with first degree heart block.
Atenolol modifies the tachycardia of hypoglycaemia.
In patients with phaeochromocytoma, a beta-blocker should only be given with an alpha-blocker.
While cardioselective beta-blockers such as atenolol may have less effect on pulmonary function than non-selective ones, they should be avoided in patients with reversible obstructive airways disease, bronchospasm or a history of asthma unless absolutely necessary. When administration is required, the use of a beta2-bronchodilator such as terbutaline may be advisable in some cases.
In patients suffering from ischaemic heart disease, as with other beta-blocking agents, treatment should not be discontinued abruptly.
Caution should be exercised when transferring patients from clonidine to beta-adrenoceptor blocking drugs. If beta-adrenoceptor blocking drugs and clonidine are given concurrently, clonidine should not be discontinued until several days after the withdrawal of the beta-adrenoceptor blocking drug.
Beta-blockers should be used with great caution in patients with peripheral circulatory disorders (Raynaud’s disease/syndrome, intermittant claudication) as they may aggravate these disorders.
Atenolol may increase the number and duration of angina attacks in patients with Prinzmetals angina. Caution must be exercised when considering using atenolol with a Prinzmetals angina patient.
Caution should be exercised when using anaesthetic agents with atenolol as there is an increased risk of hypotension and reflex tachycardia. Anaesthetics which cause myocardial depression should be avoided.
Renal failure: since atenolol is excreted via the kidneys, dosage should be adjusted in cases of severe impairment of renal function. No significant accumulation of atenolol occurs at a GFR greater than 35 ml/min/1.73m2 (normal range is 100-150 ml/min/1.73m2). For patients with a creatinine clearance of 15-35 ml/min/1.73m2 (equivalent to serum creatinine of 300-600 mcmol/litre) the oral dose should be 50 mg daily and the intravenous dose should be 10 mg once every two days. For patients with a creatinine clearance of <15 ml/min/1.73m2 (equivalent to serum creatinine of >600 mcmol/litre) the oral dose should be 25 mg daily or 50 mg on alternate days and the intravenous dose should be 10 mg once every four days.
Atenolol may cause a more serious reaction to a variety of allergens, when given to patients with a history of anaphylactic reaction to such allergens.
Such patients may be unresponsive to the usual doses of adrenaline used to treat the allergic reactions.
Patients with known psoriasis should take beta-blockers only after careful consideration.
The label will state ‘this product should not be taken if there is an history of wheezing or asthma’.
Patients on haemodialysis should be given 50 mg orally after each dialysis; this should be done under hospital supervision as marked falls in blood pressure can occur.
If a beta-blocker is withdrawn before surgery therapy, it should be discontinued for at least 24 hours.
In hypertensive patients, there is evidence that beta-blockers, including atenolol, may affect glucose metabolism and may be associated with the development of diabetes.
4.5 Interaction with other medicinal products and other forms of interaction
Other anti-hypertensive agents will potentiate the hypotensive action of atenolol.
Parenteral administration of preparations containing adrenaline to patients taking beta-adrenoceptor blocking drugs may, in rare cases, result in vasoconstriction, hypertension and bradycardia.
Beta-adrenoreceptor blocking drugs may enhance the negative inotropic and chronotropic actions of Verapamil. Therefore, concurrent use requires great care. The negative inotropic effects of class I anti-dysrhythmic agents such as disopyramide and certain anaesthetics may also be enhanced by beta-blocking drugs.
Beta-adrenoceptor blocking drugs can exacerbate the rebound hypertension associated with sudden withdrawal of clonidine.
Beta blockers may enhance hypoglycaemic effects of anti-diabetic agents and mask the warning signs of hypoglycaemia such as tremor and tachycardia.
Co-administration with an NSAID such as indomethacin or ibuprofen may lead to a decrease in the hypotensive effect of atenolol.
Concurrent administration with a cardiac glycoside may lead to an increase in atrio-ventricular conduction time.
Combined use of beta-blocking drugs and calcium channel blockers with negative inotropic effects eg Verapamil, Diltiazem can lead to an exaggeration of these effects, particularly in patients with impaired ventricular function and/or sino-atrial or atrio-ventricular conduction abnormalities. Coadministration of beta-blockers with Cimetidine or Hydralazine can increase the effect of beta-blockers.
Concurrent use of beta-blockers and alcohol can decrease the effect of beta-blockers.
4.6 Pregnancy and lactation
The safety of atenolol in pregnancy has not been established and its use should be avoided unless the potential benefits are likely to outweigh the possible risk to the foetus.
Atenolol crosses the placental barrier and appears in cord blood. There have been isolated reports of intra-uterine growth retardation in association with the use of beta-blockers. Beta-blockers may cause neonatal hypoglycaemia and bradycardia.
Beta-blocking drugs reduce placental perfusion which may result in intrauterine foetal death, immature and premature deliveries.
Atenolol is excreted in breast milk with accumulation occurring at concentrations significantly greater than corresponding plasma levels.
Nursing infants must be closely monitored for bradycardia and other signs and symptoms of beta-blockade if the mother is receiving atenolol, although breast feeding is not recommended.
4.7 Effects on ability to drive and use machines
Although symptoms such as dizziness and fatigue have occasionally been reported in association with the use of beta-blockers, the ability to drive and use machines is usually unaffected by atenolol therapy.
4.8 Undesirable effects
In clinical studies, the side effects reported are usually attributable to its pharmacological actions and include coldness of the extremities, muscular fatigue and, in isolated cases, bradycardia. Bradycardia and hypotension are usually a sign of overdosage, but may rarely be due to intolerance of the drug. Sleep disturbances of the type noted with other beta-blockers.
Atenolol is generally well tolerated. Other side effects include nausea, vomiting, dry mouth, diarrhoea, postural hypotension, confusion, dizziness, nightmares and lassitude. Headache, mood changes, psychoses, hallucinations and deterioration in heart failure may occur occasionally. Rarely thrombocytopenia, alopecia, purpura, psoriasis form skin reactions and exacerbation of psoriasis.
Precipitation of heart block, intermittent claudication and Raynaud’s phenomenon in susceptible patients have been reported.
Other side effects include paraesthesia and eyesight changes. Bronchospasm may occur in patients with bronchial asthma or a history of allergic disease.
May mask the signs of thyrotoxicosis.
An increase in ANA (anti nuclear antibodies) has been observed, however the clinical relevance of this is not clear.
There have been reports of skin rashes and/or dry eyes associated with the use of beta-adrenergic blocking drugs. The reported incidence is small and in most cases the symptoms have cleared when treatment was withdrawn. Discontinuance of the drug should be considered if any such reaction is not otherwise explicable. Cessation of therapy with a beta-blocker should be gradual.
4.9 Overdose
Clinical features of overdosage may include bradycardia, hypotension, bronchospasm, hypoglycaemia, delirium and unconsciousness. Following recent overdosage, the stomach should be emptied by gastric aspiration and lavage.
Severe bradycardia may respond to Atropine 1 to 2 mg intravenously. If necessary, this may be followed by a bolus dose of Glucagon 5 to 10 mg intravenously, followed if necessary by an intravenous infusion of Glucagon 1 to 5 mg per hour or more according to response. If there is no response to Glucagon, or if Glucagon is unavailable, a beta-adrenoceptor stimulant such as Dobutamine 2.5-10 mcg/kg/minute by intravenous infusion or Isoprenaline 1025 mcg given as an infusion at a rate not exceeding 5 mcg/minute may be given. Occasionally a temporary pacing wire may be required. Atenolol is dialysable.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Atenolol is a beta-adrenoreceptor blocking agent which has preferential effect on the beta1-receptors chiefly located in the heart (cardioselective). This selectivity diminishes with increased dosage. Atenolol does not possess intrinsic sympathomimetic activity or membrane stabilising activity. By blocking beta-receptor sites, Atenolol decreases heart rate and cardiac output, reduces systolic and diastolic blood pressure at rest and on exercise and reduces reflex orthostatic tachycardia.
5.2 Pharmacokinetic properties
Atenolol is incompletely absorbed (40-50%) after oral administration with peak plasma concentrations occurring within 2-4 hours. It exhibits low (616%) plasma protein binding. The half life of Atenolol is 6-7 hours though this may increase to 16-27 hours or more in patients with renal impairment. Atenolol is primarily eliminated unchanged (> 85%) via the kidneys with minimal hepatic metabolism.
5.3 Preclinical safety data
There are no additional data of relevance to the prescriber.
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Each tablet contains Calcium Hydrogen Phosphate (anhydrous) EP, Heavy Magnesium Carbonate EP, Sodium Starch Glycollate EP, Maize Starch EP, Collodial Anhydrous Silica EP and Magnesium Stearate EP. The film coating contains Methocel E5 EP, Titanium Dioxide EP, Polyethylene Glycol 400 EP, Quinoline Yellow Lake (E104), Sunset Yellow Lake (E110) and Carnauba Wax BP.
6.2 Incompatibilities
None known
6.3 Shelf life
3 years
6.4 Special precautions for storage
Protect from light, store below 25°C in a dry place.
6.5 Nature and contents of container
Polypropylene containers with polyethylene child resistant caps with optional use of polyethylene ullage filler or PVDC/Aluminium foil blister packs or PVC/Aluminium foil blisters. Each pack type is available in pack sizes of 5, 7, 10, 14, 15, 20, 21, 25, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 168, 180, 250, 500 and 1000 tablets.
6.6 Instruction for Use/Handling
No special requirements.
7 MARKETING AUTHORISATION HOLDER
Generics [UK] Limited T/A Mylan Station Close Potters Bar Hertfordshire EN6 1TL
8 MARKETING AUTHORISATION NUMBER(S)
PL 04569/0116
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
Date MA granted: 4 February 1986 Last renewal granted: 7 July 1994
10 DATE OF REVISION OF THE TEXT
25/01/2010