| Atenolol Pharmacology |
| Atenolol |
| About Atenolol |
| Cardioselective Beta(Beta1 )-adrenergic blocking agent, Antihypertensive,anti anginal. |
| Mechanism of Action of Atenolol |
| Atenolol is a cardio selective beta-1 adrenergic antagonist. It has negative chronotropic and negative inotropic effects on heart. It decreases oxygen consumption; cardiac work and aortic pressure. It decreases nor adrenaline and renin releases. It decreases central sympathetic out flow In sympathetic over activity, it prolongs systole by retarding conduction. It increases oxygen supply and exercise tolerance in angina patients. The drug decreases BP in hypertensive individuals; both systolic and diastolic BP is reduced. Antimigraine action: Atenolol is useful in migraine due to its beta blockade action. Through beta blockade action it inhibits vasodilation and relieves migraine. |
| Pharmacokinets of Atenolol |
| Absorption: Absorbed orally up to 60%, Distribution: Widely distributed but no CSF penetration Metabolism: A small portion is metabolized in liver. Excretion: Excreted mainly through urine. Remaining portion is excreted through faeces. |
| Onset of Action for Atenolol |
| 1hour |
| Duration of Action for Atenolol |
| Below 1day |
| Half Life of Atenolol |
| 6 – 7 hours |
| Side Effects of Atenolol |
| 1.Heart failure 2.Gastrointestinal problems 3.Nausea 4.Tiredness 5.Sinus bradycardia 6.Depression 7.Rash 8.Dizziess 9.Fatigue 10.Vomiting 11.Diarrhoea 12.Bronchospasm 13.Fever 14.Leg pain 15.Changes in kidney function tests 16.Changes in liver function tests. |
| Contra-indications of Atenolol |
| 1.Hypersensitivity to the drug 2.Second or third degree heart block 3.Heart failure 4.Cardiogenic shock 5.Sinus bradycardia |
| Special Precautions while taking Atenolol |
| 1.Congestive heart failure 2.Hepatic impairment 3.Renal impairment 4.The drug should be gradually withdraw with caution 5.Bronchospastic disorders 6.Diabetes mellitus 7.Hyper thyroidism |
| Pregnancy Related Information |
| Contraindicated |
| Old Age Related Information |
| Use with caution |
| Breast Feeding Related Information |
| Contraindicated |
| Children Related Information |
| Use with caution |
| Indications for Atenolol |
| 1.Hypertension 2. Angina 3.Myocardial infarction 4.Migraine prophylaxis |
| Interactions for Atenolol |
| Alcohol, Anaesthetics, Antidepressants, Anxiolytics, Hypnotics, Cimetidine, Diuretics: Enhanced hypotensive effect. Analgesics: NSAIDs antagonise hypotensive effect. Antibacterials (Rifampicin): Reduce plasma concentration of atenolol. Antidiabetics: Enhanced hypoglycemic effect. Antihypertensives: Enhanced hypotensive effect, with clonidine there is increased severity of rebound hypertension. Calcium channel Blockers: increased risk of bradycardia and AV block with diltiazem, severe hypotension and heart failure with verapamil, nifedipine Cardiac glycosides: Increased AV block and bradycardia. Cholinergics: Effects antagonised by atenolol. Corticosteroids: Antagonism of hypotensive effect. Ergotamine: Increased peripheral vasoconstriction Sympathomimetics: Severe hypertension with adrenaline and noradrenaline. Lab. Tests: Interferes with Glucose or insulin tolerence tests. |
| Typical Dosage for Atenolol |
| Hypertension: Starts with 50mg single dose then gradually increases at weekly intervals to 100mg/day once daily based on patient`s response. Children: 1 to 1.3 mg/kg/day once daily or as two divided doses Angina: Starts with 50mg single dose orally, and then gradually increases to 100mg/day based on patient`s response at one week intervals Maximum dose: 200mg/day Myocardial infarction: 5mg I.V. over 5minuts twice daily at 10minuts intervals. Then after 10minuts starts oral therapy with 50mg dose. Then 50mg at 12th hour. And increases to 100mg/day once daily or in two divided doses up to 9days Migraine prophylaxis: 50 – 150mg / day in divided doses |
| Schedule of Atenolol |
| H |
| Storage Requirements for Atenolol |
| Store at room temperature and protect from heat, moisture, and direct sunlight |
| Effects of Missed Dosage of Atenolol |
| Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose. |
| Effects of Overdose of Atenolol |
| Treatment is supportive and symptomatic. After ingestion empty the stomach by induced emesis or gastric lavage. Administer activated charcoal to reduce absorption |