Downloaded 67 times
Uploaded byDr. S P SRINIVAS NAYAK
Adrenaline pharmacology
The document provides an overview of adrenergic agonists, particularly focusing on adrenaline, its classification, pharmacological actions, pharmacokinetics, adverse effects, and therapeutic uses. Adrenaline acts as a potent cardiac stimulant, bronchodilator, and local vasoconstrictor, with specific applications in anaphylactic shock, asthma, and cardiac resuscitation. It notes the contraindications and side effects such as tachycardia and hypertension, emphasizing that adrenaline is not suitable for oral administration and is typically delivered through injection.
More Related Content
Similar to Adrenaline pharmacology
More from Dr. S P SRINIVAS NAYAK
Adrenaline pharmacology
- 1. ADRENERGIC AGONISTS AND PHARMACOLOGYOF ADRENALINE Dr. S P SRINIVAS NAYAK, Assistant Professor, SUCP, HYD. Telangana, India.
- 2. Classification of Sympathomimetics/ Adrenergic Agonists Classificationof On the basis of their therapeutic use: 1. Nasal decongestants: Phenylephrine, xylometazoline, pseudoephedrine, oxymetazoline, naphazoline
- 3. 2. For allergicreactions (anaphylactic shock): Adrenaline
- 4. 3. To raisethe blood pressure in shock: Dopamine, noradrenaline, ephedrine, phenylephrine, methoxamine, mephentermine
- 5.
- 6. 5. As cardiacstimulant: • Adrenaline, isoprenaline, dobutamine.
- 7. 6. As CNSstimulant: Amphetamine, dextroamphetamine.
- 8. 7. For localvasoconstrictor effect: Adrenaline. Adrenaline is used as a local haemostatic to control bleeding following tooth extraction and during surgical procedures in nose, throat, larynx, or in cuts, injuries etc. because of its vasoconstrictor effect.
- 9.
- 10. ADRENALINE (EPINEPHRINE) It isa catecholamine, which is secreted mainly by adrenal medulla. Adrenaline is a direct acting nonselective adrenergic agonist
- 11. PHARMACOLOGICAL ACTIONS OF ADRENALINE •1. Cardiovascular system(CVS) a. Heart: Adrenaline is a powerful cardiac stimulant i. Increase in heart rate (positive chronotropic effect). ii. Increase in myocardial contractility (positive inotropic effect). iii. Increase in conduction velocity (positive dromotropic effect b. Blood vessels and BP: Blood vessels of the skin and mucous membranes are constricted by adrenaline. It also constricts renal, mesenteric, pulmonary and splanchnic vessels, but dilates the blood vessels of skeletal muscle and coronary vessels .
- 13. 2. RESPIRATORY SYSTEM: Adrenalinerapidly relaxes (beta.2) bronchial smooth muscle. It is a potent bronchodilator but has a short duration of action. It inhibits the release of inflammatory mediators from mast cells (beta.2). It also reduces secretions and relieves mucosal congestion by vasoconstrictor effect (alpha.1).
- 14. 3. Gastro intestinaltract(GIT) • It relaxes the smooth muscle of the gut. • It reduces the intestinal tone and peristaltic movements. • Mostly it causes Constipation
- 15. 4. Bladder: • Itrelaxes the detrusor muscle and contracts the sphincter. As a result, it may cause difficulty in urination.
- 16. 5. CNS: • Intherapeutic doses, adrenaline does not cross the BBB and hence CNS effects are very minimal. • But in high doses, it may cause headache, restlessness and tremor.
- 17. 6. METABOLIC EFFECTS: •Adrenaline increases the blood glucose level by: i. Stimulating hepatic glycogenolysis (beta2), which is the predominant effect. ii. Reducing insulin secretion. iii. Decreasing the uptake of glucose by peripheral tissues.
- 18. 7. Other effectson each cell • It reduces plasma K+ levels by promoting the uptake of K+ into the cells, particularly into the skeletal muscle. • It causes hypokalemia
- 19. PHARMACOKINETICS Adrenaline is notsuitable for oral administration because of its rapid inactivation in the GI mucosa and liver. Adrenaline can be given subcutaneously (s.c.). In anaphylactic shock, the absorption of s.c. adrenaline is very poor, hence given intramuscularly. In cardiac arrest, it is given intravenously. It does not cross the BBB; is rapidly metabolized by COMT and MAO and the metabolites are excreted in urine.
- 20. ADVERSE EFFECTS • Theyare tachycardia, palpitation, headache, restlessness, tremor and rise in BP. • The serious side effects are cerebral haemorrhage and cardiac arrhythmias. • In high concentration, adrenaline may cause acute pulmonary oedema due to shift of blood from systemic to pulmonary circulation. • Adrenaline is contraindicated in most of the cardiovascular diseases such as hypertension, angina, cardiac arrhythmias, CCF, etc. • It should also be avoided in patients on beta-blockers because it may cause hypertensive crisis and cerebral haemorrhage due to unopposed action on vascular alpha 1-receptors.
- 21. USES OF ADRENALINE •Anaphylactic shock • bronchial asthma • Cardiac resuscitation, hypotension • Prolongs the Duration of local anaesthesia • controls Epistaxis and other capillary oozing
- 22.