| Adrenaline Pharmacology |
| Adrenaline |
| About Adrenaline |
| Alpha and Beta adrenergic agonist, catecholamine, Vasoconstrictor., Anti asthma, inanaphylatic shock. |
| Mechanism of Action of Adrenaline |
| Adrenaline is an alpha and beta adrenergic agonist which exerts it`s therapeutic actions through predominant beta receptor agonistic action. It is a positive inotropic and chronotropic drug and it increases stroke volume, cardiac output and improves coronary blood flow. It increases systolic and mean blood pressure. It increases blood flow to skeletal muscles. It is a powerful bronchial smooth muscle relaxant and antagonizes spasm of bronchial muscle. It acts through alpha receptors in skin, mucous membrane, and viscera and causes vasoconstriction and which reduces absorption of local anaesthetics localizes and prolongs the duration of anaesthesia. Local vasoconstrictor action also produces haemostasis.Role in local anaesthesia: The speed of onset and duration of action of local anaesthetics may be increased by the addition of vasoconstrictors like Adrenaline which has the effect of reducing the uptake of the local anaesthetic into the circulation from the injection site. Vasoconstrictors should not be used when producing a nerve block in an appendage such as a digit, as gangrene may occur. Vasoconstrictors have been added to injections for spinal block, but their use is not recommended because of the danger of reducing the blood supply to the spinal cord. |
| Pharmacokinets of Adrenaline |
| Absorption: Well absorbed after sub cutaneous or intramuscular injection. Distribution: Widely distributed through out the body. Metabolism: Metabolized in to inactive metabolites in sympathetic nerve endings, liver and other tissues. Excretion: Excreted through urine as metabolites and conjugates. |
| Onset of Action for Adrenaline |
| I.V.: Rapid Subcutaneous: 5 to 15minutes Inhalation: Within 5 minutes |
| Duration of Action for Adrenaline |
| I.M.: 1 to 4 hours I.V.: Short Subcutaneous: 1 to 4 hours Inhalation: 1 to 3 hours |
| Half Life of Adrenaline |
| N/A |
| Side Effects of Adrenaline |
| 1.Palpitation 2.Hypertension 3.Tachycardia 4.Ventricular fibrillation 5.Shock 6.Anginal pain 7.ECG changes 8.Arrhythmias 9. Tremor 10.Nervousness 11.Headache 12.Vertigo 13.Disorientation 14.Agitation 15.Dizziness 16.Drowsiness 17.Fear 18.Weakness 19.Lightheadedness 20.Nervousness 21.Excitation 22.Dyspnoea 23.Nausea 24.Vomiting. |
| Contra-indications of Adrenaline |
| 1.Hypersensitivity to the drug, 2.Shock other than anaphylactic shock, 3.Angle closure glaucoma, 4.Anaesthesia of extreamities, 5.During labour, 6.Cardiac dilatation, 7.Coronary insufficiency, 8.Organic brain damage, 9.Cerebral arteriosclerosis, 10.Arrhythmias, 11.Along general anaesthesia with halogenated hydrocarbons or cyclopropane. |
| Special Precautions while taking Adrenaline |
| 1.Bronchial asthma 2.Emphysema 3.Hyperthyroidism 4.Cardiovascular disease 5.Psychoneurosis 6.Diabetes 7.Parkinson`s disease(ophthalmic preparation) |
| Pregnancy Related Information |
| Contraindicated |
| Old Age Related Information |
| Use with caution |
| Breast Feeding Related Information |
| Contraindicated |
| Children Related Information |
| Use with caution |
| Indications for Adrenaline |
| 1.Bronchospasm 2.Bronchodilator 3.Hypersensitivity reactions 4.Anaphylactic shock 5.To restore cardiac rhythm in cardiac arrest 6.Haemostasis 7.Prolong duration of anaesthesia 8.Nasal congestion 9.Open angle glaucoma. |
| Interactions for Adrenaline |
| Beta Blockers: Concomitant administration may block beta adrenergic effects of adrenaline causing hypertension. Cardiac glycosides: May make cardiac arrhythmias more likely. Ergot alkaloids and phenothiazines: May reverse the pressor effects of adrenaline. Antihistamines: Pressor effect may be potentiated. Halogenated hydrocarbon anaesthetics: Sensitise the myocardium to the effects of catecholamines leading to serious arrhythmias. Oxytocic drugs: May cause severe persistent hypertension. Sympathomimetic drugs: Additive effects and increased toxicity. May induce serious cardiac arrhythmias. Tricyclic antidepressants: Pressor response may be potentiated. |
| Typical Dosage for Adrenaline |
| Bronchospasm, Hypersensitivity reactions, Anaphylaxis: Adults: Starts with 0.1 to 0.5mg (0.1 to 0.5ml of a 1: 1,000 solution) S.C. or I.M. Repeat as required at 10 to 15minute intervals. Alternatively 0.1 to 0.25mg (1 to 2.5ml of a 1: 10,000 solution) I.V.; slowly over 5 to 10 minutes. Repeated if required at every 5 to 15minutes or followed by 1 to 4mcg/minute I.V. infusion. Children: 0.01mg/kg (0.01ml/kg of a 1: 1000 solution) S.C. Dose not to exceed 0.5mg. Repeated as required; at every 20 minutes to 4hour intervals. Alternatively 0.02 to 0.025 mg/kg (0.004 to0.005 mi/kg) of a 1:200 solution. Repeat if required but not to exceed than four times daily. Alternatively To restore cardiac rhythm in cardiac arrest: Starts with 0.5 to 1mg (5 to 10ml of 1: 10,000 solutions) diluted to 10ml and administered I.V. or intra cardiac. During resuscitation 0.5 to 1mg I.V. every 5minutes or injected through endotracheal tube. Administer 10ml containing 1ml adrenaline (0.1mg/ml) by 5 rapid insufflations directly in to the tube and followed by 5 rapid insufflations. Adults: I.V.: 100mcg to 250mcg injected slowly. Neonates: 0.01mg/kg Infants: 50mcg initial dose repeated at 20 to 30 minutes intervals in asthma attacks. Resuscitation for children and neonates: 0.iml/kg of 1: 10000solution I.V. As a haemostatic agent: Adults: 1: 50,000 to 1: 1000 applied topically. To prolong local anaesthetic effect: 1:500000 to 1: 50000 mixed with local anaesthetic agent. Intra spinal use: 0.2 to 0.4ml of 1: 2000 solutions added to anaesthetic fluid to prolong anaesthetic action. Nasal congestion, local superficial bleeding: Instill 1 to 2 drops of solution. Open angle glaucoma: 1 to 2 drops instill daily or twice daily. |
| Schedule of Adrenaline |
| C & C1. |
| Storage Requirements for Adrenaline |
| Store below 25 degree C and protects from light. |
| Effects of Missed Dosage of Adrenaline |
| N/A |
| Effects of Overdose of Adrenaline |
| Treatment is supportive and symptomatic. Epinephrine is rapidly inactivated in the body. Closely monitor vital signs. Treat hypotension with Phentolamine & arrhythmias with beta blockers like Propranolol. |
| Adenosine Pharmacology |
| Adenosine |
| About Adenosine |
| Naturally occuring purine Nucleoside,Class IV Antiarrhythmic Agent, Diagnostic Agent. |
| Mechanism of Action of Adenosine |
| Adenosine is a nucleoside; administered as freebase or ATP. It exerts it`s pharmacological action by activating acetyl choline sensitive K+ channels and causes membrane hyperpolarisation through interaction with A1 type of G protein coupled adenosine receptors on SA node and thus causes depression, prolongation of effective refractory period and slowing of conduction in AV node, shortening of action potential and reduced excitability in atrium. It also indirectly reduces Ca2+ current in AV node; depression of reentrant circuit through AV node is responsible for its action against Paroxysmal supra ventricular tachycardia. Adrenergically induced after depolarization; in ventricles is also suppressed. It also causes transient coronary dilatation and it is a local mediator involved in auto regulation of coronary flow in response to ischaemia. |
| Pharmacokinets of Adenosine |
| Absorption: It should be administered parenterally as rapid I.V. injection. Distribution: Distributed mostly in to vascular endothelial cells and erythrocytes. Metabolism: Metabolized within the tissues in to inosine monophosphate and adenosine monophosphate and finally in to xanthine |
| Onset of Action for Adenosine |
| N/A |
| Duration of Action for Adenosine |
| N/A |
| Half Life of Adenosine |
| Below 10 seconds |
| Side Effects of Adenosine |
| 1.Headache 2.Hypotension 3.Facial flushing 4.Palpitations 5.Diaphoresis 6.Nausea 7.Metallic taste 8.Dyspnea 9.Chest pain 10.Shortness of breath 11.Hyperventilation 12.Tightness in throat 13.Blurred vision 14.Back pain 15.Dizziness 16.Light- headedness 17.Tingling in fingers 18.Neck pain 19.Metallic taste 20.Burning sensation |
| Contra-indications of Adenosine |
| 1.Hypersensitivity to the drug 2.Second or third degree heart block 3.Sick sinus syndrome 4.Bronchial asthma 5.Atrial fibrillation 6.Atrial flutter |
| Special Precautions while taking Adenosine |
| 1.Bronchospasm 2.Patient with an accessory bypass tract or in atrial flutter or atrial fibrillation may develop increased conduction down the anomalous pathway. 3.Patients in whom significant heart bock develops after a dose of adenosine should not receive additional doses. 4.Along with Dipyridamole. |
| Pregnancy Related Information |
| Use with caution |
| Old Age Related Information |
| Use with caution |
| Breast Feeding Related Information |
| Contraindicated |
| Children Related Information |
| N/A |
| Indications for Adenosine |
| 1.Paroxysmal supra ventricular tachycardia 2.Diagnosis of re-entrant atrial and ventricular tachycardia. |
| Interactions for Adenosine |
| Dipyridamole: Potentiate the Adenosine effects Methyl xanthines(Caffeine, Theophylline): Antagonises adenosine effects Carbamazepine: Concomitant use of Carbamazepine with Adenosine increases the heart block |
| Typical Dosage for Adenosine |
| Adults: Starts with 3mg I. V.; by rapid bolus injection over 1 to 2 seconds. Then 6mg may be given after 1 to 2 minutes if required. Further increase in dose up to 12mg and repeat the same dose if required. Children: Starts with 50 to 100mcg/kg. Increase if required by increments of same dose at 1 to 2 minutes intervals until therapeutic goal is achieved. Maximum child dose: 300mcg/kg. |
| Schedule of Adenosine |
| H |
| Storage Requirements for Adenosine |
| Store at controlled room temperature at a range of 15 to 30 degree C. Do not refrigerate and discard unused portion. |
| Effects of Missed Dosage of Adenosine |
| N/A |
| Effects of Overdose of Adenosine |
| Adverse effects of overdose are self limiting, because half life is lower than 10 seconds. Treatment is supportive and symptomatic |