The symptoms of overdosage may include bradycardia, hypotension, acute cardiac insufficiency and bronchospasm.
General treatment should include: close supervision, treatment in an intensive care ward, the use of gastric lavage, activated charcoal and a laxative to prevent absorption of any drug still present in the gastrointestinal tract, the use of plasma or plasma substitutes to treat hypotension and shock. The possible use of haemodialysis or haemoperfusion may be considered.
Excessive bradycardia may be countered with atropine 1-2 mg intravenously and/or a cardiac pacemaker. If necessary, this may be followed by a bolus dose of glucagon 10 mg intravenously. If required, this may be repeated or followed by an intravenous infusion of glucagon 1-10 mg/hour depending on response. If no response to glucagon occurs or if glucagon is unavailable, a beta-adrenoceptor stimulant such as dobutamine 2.5 to 10 micrograms/kg/minute by intravenous infusion may be given. Dobutamine, because of its positive inotropic effects could be used to treat hypotension and acute cardiac insufficiency. It is likely that these doses would be inadequate to reverse the cardiac effects of beta-blocker blockade if a large overdose has been taken. The dose of dobutamine should therefore be increased if necessary to achieve the required response according to the clinical condition of the patient.
Bronchospasm can usually be reversed by bronchodilators.
Excessive diuresis should be countered by maintaining normal fluid and electrolyte balance.
4 years.
Not applicable.
Heavy Magnesium Carbonate
Maize Starch.
Sodium laurilsulfate
Gelatin
Magnesium Stearate
Methylhydroxypropylcellulose.
Macrogol 300 BP
Iron Oxide yellow (E172)
Iron Oxide red (E172)
Magnesium Carbonate.
Tabulated list of adverse reactions
Tenoretic tablets are well tolerated. In clinical studies, the undesired events reported are usually attributable to the pharmacological actions of its components.
The following undesired events, listed by body system, have been reported with the following frequencies: very common (>1/10); common (>1/100 to <1/10); uncommon (>1/1,000 to <1/100); rare ((>1/10,000 to <1/1,000); very rare (<1/10,000); not known (cannot be estimated from the available data).
| System Organ Class | Frequency | Adverse Drug Reaction |
| Blood and lymphatic system disorders | Rare | Purpura, thrombocytopenia, leucopenia (related to chlortalidone) |
| Psychiatric disorders | Uncommon | Sleep disturbances of the type noted with other beta blockers |
| Rare | Mood changes, nightmares, confusion, psychoses and hallucinations | |
| Nervous system disorders | Rare | Dizziness, headache, paraesthesia |
| Eye disorders | Rare | Dry eyes, visual disturbances |
| Cardiac disorders | Common | Bradycardia |
| Rare | Heart failure deterioration, precipitation of heart block | |
| Vascular disorders | Common | Cold extremities |
| Rare | Postural hypotension which may be associated with syncope, intermittent claudication may be increased if already present, in susceptible patients Raynaud's phenomenon | |
| Respiratory, thoracic and mediastinal disorders | Rare | Bronchospasm may occur in patients with bronchial asthma or a history of asthmatic complaints |
| Gastrointestinal disorders | Common | Gastrointestinal disturbances (including nausea related to chlortalidone) |
| Rare | Dry mouth | |
| Not known | Constipation | |
| Hepatobiliary disorders | Rare | Hepatic toxicity including intrahepatic cholestasis, pancreatitis (related to chlortalidone) |
| Skin and subcutaneous tissue disorders | Rare | Alopecia, psoriasiform skin reaction, exacerbation of psoriasis, skin rashes |
| Not known | Hypersensitivity reactions, including angioedema and urticaria | |
| Musculoskeletal and connective tissue disorders | Not known | Lupus-like syndrome |
| Reproductive system and breast disorders | Rare | Impotence |
| General disorders and administration site conditions | Common | Fatigue |
| Investigations | Common | Related to chlortalidone: Hyperuricaemia, hyponatraemia, hypokalaemia, impaired glucose tolerance |
| Uncommon | Elevations of transaminase levels. | |
| Very rare | An increase in ANA (Antinuclear Antibodies) has been observed, however the clinical relevance of this is not clear |
Discontinuance of Tenoretic tablets should be considered if, according to clinical judgement, the well-being of the patient is adversely affected by any of the above reactions.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme. Website: www.mhra.gov.uk/yellowcard
Atenolol and chlortalidone are drugs on which extensive clinical experience has been obtained. Relevant information for the prescriber is provided elsewhere in the Summary of Product Characteristics.
Pharmacotherapeutic group: Beta-blocking agents, selective, and other diuretics.
C07C B03
Tenoretic tablets combines the antihypertensive activity of two agents, a beta-blocker (atenolol) and a diuretic (chlortalidone).
Atenolol
Atenolol is beta1-selective (i.e. acts preferentially on beta1-adrenergic receptors in the heart). Selectivity decreases with increasing dose.
Atenolol is without intrinsic sympathomimetic and membrane-stabilising activities and, as with other beta-adrenoceptor blocking drugs, has negative inotropic effects (and is therefore contraindicated in uncontrolled heart failure).
As with other beta-blockers, the mode of action in the treatment of hypertension is unclear.
It is unlikely that any additional ancillary properties possessed by S (-) atenolol, in comparison with the racemic mixture, will give rise to different therapeutic effects.
Atenolol is effective and well-tolerated in most ethnic populations. Black patients respond better to the combination of atenolol and chlortalidone, than to atenolol alone.
The combination of atenolol with thiazide-like diuretics has been shown to be compatible and generally more effective than either drug used alone.
Chlortalidone
Chlortalidone, a monosulfonamyl diuretic, increases excretion of sodium and chloride. Natriuresis is accompanied by some loss of potassium. The mechanism by which chlortalidone reduces blood pressure is not fully known but may be related to the excretion and redistribution of body sodium.
Atenolol
Absorption of atenolol following oral dosing is consistent but incomplete (approximately 40-50%) with peak plasma concentrations occurring 2-4 hours after dosing. The atenolol blood levels are consistent and subject to little variability. There is no significant hepatic metabolism of atenolol and more than 90% of that absorbed reaches the systemic circulation unaltered. The plasma half-life is about 6 hours but this may rise in severe renal impairment since the kidney is the major route of elimination. Atenolol penetrates tissues poorly due to its low lipid solubility and its concentration in brain tissue is low. Plasma protein binding is low (approximately 3%).
Chlortalidone
Absorption of chlortalidone following oral dosing is consistent but incomplete (approximately 60%) with peak plasma concentrations occurring about 12 hours after dosing. The chlortalidone blood levels are consistent and subject to little variability. The plasma half-life is about 50 hours and the kidney is the major route of elimination. Plasma protein binding is high (approximately 75%).
Coadministration of chlortalidone and atenolol has little effect on the pharmacokinetics of either.
Tenoretic tablets is effective for at least 24 hours after a single oral daily dose. This simplicity of dosing facilitates compliance by its acceptability to patients.
12th January 2017
AstraZeneca UK Limited
600 Capability Green,
Luton, LU1 3LU, UK.
Do not store above 25°C.
Store in the original package. Keep the container in the outer carton
Blister packs of 28 tablets contained in a carton.
17901/0049
Fertility:
No data on fertility available.
Pregnancy:
Tenoretic tablets must not be given during pregnancy.
Lactation:
Tenoretic tablets must not be given during lactation.
Use is unlikely to result in any impairment of the ability of patients to drive or use machinery. However, it should be taken into account that occasionally dizziness or fatigue may occur.
No special requirements for disposal.
Date of first authorisation: 1st June 2000
Date of latest renewal: 9th February 2005
