p.2
Physiological Effects of Adrenergic Receptors
What effect do adrenergic agonists have on the eye?
They cause mydriasis (dilatation of the pupil).
p.7
Pharmacological Actions of Adrenaline and Noradrenaline
What is the primary pharmacological action of Clonidine?
Acts centrally at the nucleus tractus solitarius to decrease sympathetic outflow.
p.2
Physiological Effects of Adrenergic Receptors
How do adrenergic agonists affect the urinary bladder?
They relax the urinary bladder.
p.1
Physiological Effects of Adrenergic Receptors
What is the function of α1 adrenergic receptors?
Post-synaptic excitatory, causing contraction except in the gastrointestinal tract.
p.3
Classification of Adrenergic Agonists
What is the significance of the catechol ring in adrenergic agonists?
It makes the compound water-soluble and leads to rapid degradation by MAO and COMT.
p.8
Adrenergic Agonists: Direct and Indirect Actions
How does amphetamine act as an indirect adrenergic stimulant?
By releasing norepinephrine (NE) from presynaptic stores at adrenergic terminals.
p.7
Clinical Applications of Adrenergic Agonists
What is a tocolytic?
A drug that relaxes the uterus to treat premature labor.
p.6
Clinical Applications of Adrenergic Agonists
What topical applications does dopamine have?
Haemostatic, mydriatic, and nasal decongestant.
p.8
Pharmacological Actions of Adrenaline and Noradrenaline
What is tachyphylaxis in relation to amphetamine?
A reduction of response after repeated administration due to depletion of vesicles from stored NE.
p.2
Physiological Effects of Adrenergic Receptors
What is the primary effect of adrenergic agonists?
To produce effects similar to stimulation of the sympathetic nervous system.
p.6
Dopamine and Dobutamine: Mechanisms and Uses
What type of neurotransmitter is dopamine?
A natural catecholamine and CNS transmitter.
p.6
Dopamine and Dobutamine: Mechanisms and Uses
What is the metabolism process of dobutamine?
Metabolized by COMT, resulting in a short duration of action.
p.5
Physiological Effects of Adrenergic Receptors
What is the effect of β3 receptors activated by norepinephrine?
Induces lipolysis and hyperglycemia.
p.4
Adrenergic Receptors Overview
What type of receptor is adrenaline primarily associated with?
Non-selective adrenergic receptors (α1, α2, β1, β2, β3).
p.2
Physiological Effects of Adrenergic Receptors
What effect do adrenergic agonists have on the bronchi?
They cause bronchodilation.
p.2
Physiological Effects of Adrenergic Receptors
What metabolic effect do adrenergic agonists have?
They increase the conversion of glycogen to glucose, leading to hyperglycemia.
p.3
Classification of Adrenergic Agonists
What is the mechanism of indirect adrenergic agonists?
They stimulate adrenergic receptors by increasing norepinephrine release or inhibiting its uptake.
p.8
Clinical Applications of Adrenergic Agonists
What is pseudoephedrine primarily used for?
As a nasal and ocular decongestant and in flu remedies.
p.6
Clinical Applications of Adrenergic Agonists
What is the drug of choice for treating shocks?
Dopamine, as it increases blood pressure without causing renal impairment.
p.1
Physiological Effects of Adrenergic Receptors
What is the effect of adrenergic stimulation on the urinary bladder?
It causes contraction of the urinary bladder's sphincter, leading to urinary retention.
p.4
Side Effects and Contraindications of Adrenergic Drugs
What are common adverse drug reactions (ADRs) of adrenaline?
Tachycardia, arrhythmias, headache, and hypertension.
p.7
Adrenergic Agonists: Direct and Indirect Actions
What type of drug is Clonidine?
A synthetic imidazoline and alpha-2 agonist.
p.7
Clinical Applications of Adrenergic Agonists
What are Salbutamol and Terbutaline primarily used for?
Bronchodilation for acute attacks of asthma and COPD.
p.8
Side Effects and Contraindications of Adrenergic Drugs
What are the adverse effects of amphetamine?
Psychic and physical dependence, psychosis, and it is not used therapeutically anymore.
p.3
Classification of Adrenergic Agonists
What is an example of a non-selective adrenergic agonist?
Norepinephrine, which acts on alpha and beta receptors.
p.1
Physiological Effects of Adrenergic Receptors
What is the effect of adrenergic stimulation on heart rate?
Increases heart rate (+ chronotropic effect) and can cause tachycardia.
p.1
Physiological Effects of Adrenergic Receptors
What is the function of α2 adrenergic receptors?
They inhibit norepinephrine release through a negative feedback mechanism.
p.4
Physiological Effects of Adrenergic Receptors
What is the effect of adrenaline on insulin and glucagon levels?
It decreases insulin (α1) and increases glucagon (β2).
p.5
Classification of Adrenergic Agonists
What type of agonist is isoprenaline?
A non-selective β agonist.
p.5
Physiological Effects of Adrenergic Receptors
What is a significant effect of norepinephrine on blood vessels?
Severe vasoconstriction via α1 receptors.
p.8
Pharmacological Actions of Adrenaline and Noradrenaline
Why does amphetamine have a longer duration of action?
It is not destroyed by monoamine oxidase (MAO).
p.6
Dopamine and Dobutamine: Mechanisms and Uses
What is a key characteristic of dobutamine?
It has a prolonged duration of action since it is not inactivated by COMT.
p.3
Classification of Adrenergic Agonists
What are dual adrenergic agonists?
Agents that have both direct and indirect stimulation of adrenergic receptors, such as ephedrine and pseudoephedrine.
p.6
Pharmacological Actions of Adrenaline and Noradrenaline
What happens at high doses of α1 receptor activation?
Vasoconstriction and hypertension, with little effect on heart rate.
p.3
Classification of Adrenergic Agonists
What is an example of a delayed action adrenergic agonist?
Synthetic non-catecholamines like ephedrine and amphetamine.
p.7
Clinical Applications of Adrenergic Agonists
What is Brimonidine used for?
To reduce intraocular pressure in glaucoma.
p.2
Physiological Effects of Adrenergic Receptors
What effect do adrenergic agonists have on the uterus?
They relax the uterus, delaying premature labor.
p.3
Classification of Adrenergic Agonists
What are direct adrenergic agonists?
Agents that stimulate adrenergic receptors directly, such as adrenaline, noradrenaline, and dopamine.
p.8
Adrenergic Agonists: Direct and Indirect Actions
What is the mechanism of action for ephedrine?
Acts directly on receptors and indirectly by releasing NE from adrenergic nerve endings.
p.5
Pharmacological Actions of Adrenaline and Noradrenaline
How is norepinephrine administered?
Only by intravenous (I.V) route.
p.6
Dopamine and Dobutamine: Mechanisms and Uses
How is dopamine released?
From postganglionic adrenergic fibers.
p.5
Clinical Applications of Adrenergic Agonists
What is a common use of isoprenaline?
Mainly in cardiac arrest and rarely in acute asthma attacks.
p.6
Dopamine and Dobutamine: Mechanisms and Uses
How is dobutamine administered?
Given parentally by infusion or orally.
p.3
Classification of Adrenergic Agonists
What distinguishes selective adrenergic agonists?
They target specific adrenergic receptor subtypes, such as phenylephrine for alpha-1 and clonidine for alpha-2.
p.1
Pharmacological Actions of Adrenaline and Noradrenaline
What role does renin play in the body?
It is involved in the production of angiotensin II, a potent vasoconstrictor.
p.4
Physiological Effects of Adrenergic Receptors
What is the effect of low doses of adrenaline on blood pressure?
It can lead to hypotension by stimulating β2 receptors.
p.4
Physiological Effects of Adrenergic Receptors
What effect does adrenaline have on the lungs?
It causes bronchodilation (β2).
p.4
Side Effects and Contraindications of Adrenergic Drugs
What are some contraindications for using adrenaline?
Congestive heart disease, hyperthyroidism, and closed-angle glaucoma.
p.7
Clinical Applications of Adrenergic Agonists
What are the indications for Phenylephrine?
Treatment of nasal stuffiness.
p.5
Side Effects and Contraindications of Adrenergic Drugs
What are the contraindications for norepinephrine?
Hyperthyroidism and congestive heart disease.
p.8
Administration & Metabolism
What are the pharmacokinetics of ephedrine?
Absorbed orally, not destroyed by MAO or catechol-O-methyltransferase (COMT), leading to prolonged action.
p.4
Physiological Effects of Adrenergic Receptors
What effect does adrenaline have on heart function?
It increases inotropic, chronotropic, and dromotropic activity (β1).
p.2
Physiological Effects of Adrenergic Receptors
How do adrenergic agonists affect heart rate?
They increase heart rate.
p.2
Physiological Effects of Adrenergic Receptors
What is the effect of adrenergic agonists on gastrointestinal motility?
They inhibit peristalsis and secretion.
p.5
Pharmacological Actions of Adrenaline and Noradrenaline
What are the cardiovascular effects of norepinephrine?
Increases blood pressure and induces reflex bradycardia.
p.8
Physiological Effects of Adrenergic Receptors
What are the CNS effects of amphetamine?
Mental alertness, wakefulness, concentration, self-confidence, depression, fatigue, euphoria, appetite loss, and increased energy expenditure.
p.5
Physiological Effects of Adrenergic Receptors
What effect does norepinephrine have on cardiac output?
Increases force of contraction but decreases heart rate.
p.8
Classification of Adrenergic Agonists
What is a key difference between pseudoephedrine and ephedrine?
Pseudoephedrine has less pressor effects compared to ephedrine.
p.5
Adrenergic Agonists: Direct and Indirect Actions
What is norepinephrine primarily released by?
Adrenergic neurons as the primary neurotransmitter.
p.5
Clinical Applications of Adrenergic Agonists
Why is norepinephrine not useful in treating asthma?
Due to its weak β2 activity, which does not induce bronchodilation.
p.6
Pharmacological Actions of Adrenaline and Noradrenaline
What are the pharmacological actions of low-dose D1 dopamine?
Vasodilation of mesenteric, coronary, and renal blood vessels, leading to improved blood flow and diuresis.
p.4
Pharmacological Actions of Adrenaline and Noradrenaline
What is the onset and duration of action for adrenaline?
Fast onset and short duration of action.
p.4
Clinical Applications of Adrenergic Agonists
What is the drug of choice for anaphylactic shock?
Adrenaline, given subcutaneously.
p.7
Side Effects and Contraindications of Adrenergic Drugs
What happens when selective adrenergic drugs are given in high doses?
They can become non-selective.
p.6
Pharmacological Actions of Adrenaline and Noradrenaline
What effects does β1 receptor activation have at intermediate doses?
+ve inotropic and +ve chronotropic effects, increasing blood pressure.
p.4
Pharmacological Actions of Adrenaline and Noradrenaline
How is adrenaline administered?
Intravenously (IV), subcutaneously (SC), inhalation, and topically.
p.1
Types of Adrenergic Receptors: Alpha and Beta
What are the two main types of adrenergic receptors?
Alpha (α) and Beta (β) adrenoceptors.
p.3
Classification of Adrenergic Agonists
What are non-catecholamines?
Adrenergic agonists that lack a catechol ring, are lipid-soluble, and can be administered orally.
p.1
Physiological Effects of Adrenergic Receptors
What happens to blood glucose levels during adrenergic stimulation?
Blood glucose levels increase (hyperglycemia) due to decreased insulin and increased glycogenolysis.
p.1
Physiological Effects of Adrenergic Receptors
What is the primary function of β1 adrenergic receptors?
Excitatory function mainly present in the heart, increasing heart rate and force of contraction.
p.3
Classification of Adrenergic Agonists
What is an example of a rapidly acting adrenergic agonist?
Natural catecholamines like norepinephrine and epinephrine.
p.4
Physiological Effects of Adrenergic Receptors
What is the action of adrenaline on vascular smooth muscle?
It constricts skin and peripheral vessels (α1) and dilates coronary and skeletal vessels (β2).
p.3
Classification of Adrenergic Agonists
What are catecholamines?
Adrenergic agonists that have a catechol ring, are water-soluble, and have a short half-life.
p.1
Physiological Effects of Adrenergic Receptors
What is the effect of adrenergic receptors on blood pressure?
They can increase blood pressure through vasoconstriction.
p.1
Physiological Effects of Adrenergic Receptors
What effect do β2 adrenergic receptors have on smooth muscles?
They cause relaxation, including in the uterus and bronchial smooth muscles.
p.4
Pharmacological Actions of Adrenaline and Noradrenaline
Why is adrenaline not effective when taken orally?
It is inactivated by intestinal enzymes.
p.4
Physiological Effects of Adrenergic Receptors
What is the role of adrenaline in the gastrointestinal tract?
It decreases motility (β2) and contracts sphincters (α1).
p.4
Physiological Effects of Adrenergic Receptors
What happens to blood pressure at high doses of adrenaline?
Systolic blood pressure increases and diastolic blood pressure decreases.
p.4
Clinical Applications of Adrenergic Agonists
What are some indications for local use of adrenaline?
As a hemostatic agent and combined with local anesthetics.
