Adrenergic Drugs

This class of drugs mimic sympathetic function. They do so either by directly stimulating the adrenergic receptors or by allowing more epinephrine to be present in the synaptic cleft. Indirect acting agents of this class either cause release of neurotransmitter or prevent the normal termination of action (reuptake).

What are the subclasses within sypathomimetics? (4)

Are catecholamines effective by the oral route?

What are the subclasses of Catecholamines? (3)

Endogenous sympathetic substances within the class of Sympathomimetics

A catecholamine that acts on all alpha- and beta-adrenoreceptors in the body. The primary catecholamine liberated from the adrenal medulla. Not effective when given orally. Short duration of action. Given parenterally or by inhalation. The combined use of an alpha- and a beta-adrenoreceptor blockade would eliminate all response to this.

What type of receptors does epinephrine act on?

Is epinephrine short or long duration?

What is the effect of epinephrine on the heart?

What drug acts on beta₂-adrenoreceptors to relax bronchial smooth muscle in the treatment of asthma and for treating bronchospasm during anaphylactic shock?

Which catecholamine is the neurotransmitter released from sympathetic nerve endings acting on all alpha-adrenoreceptors as well as the beta₁-adrenoreceptors? Not clinically useful. Not orally effective. Very short acting even when administered parenterally. A bolus injection will increase blood pressure due to both vasoconstriction and increased cardiac output.

What receptors do norepinephrine act on?

What will a bolus injection of NE do?

Which catecholamine is a synthetic compound and is an almost pure beta-adrenergic stimulant? Acts potently on all beta-adrenoreceptors. Route of administration is injection or inhalation. Main use is to relieve bronchoconstrictive states with the cardiovascular effects usually being untoward side effects.

Which receptor types do Isoproterenol work on?

What is the main use of Isoproterenol?

Which drugs are classified as non-catecholamine, alpha agonist Sympathomimetics? (5)

That non-catecholamic alpha agonist is a potent indirect acting sympathomimetic which causes a massive release of NE from sympathetic nerve endings. Found in high concentrations in certain foods. Readily inactivated by mitochondrial MAO in the gut and the liver. May precipitate a hypertensive crisis in patients taking a MAO inhibitor to treat depression. Useful experimental tool to establish the integrity of sympathetic neurons

Indirect acting sympathomimetics that are orally effective and readily enter the CNS. Dangerous drugs. Limited therapeutic justification. Produce a temporary elevation of mood and appetite suppression. Rebound depression typically develops. Highly toxic. Can be lethal. Chronic toxicity can mimic schizophrenia (reversible upon withdrawal). Only two valid medical uses: Hyperkinetic childen and narcoleptics

What are the two medical uses for amphetamines?

An alpha agonist, non-catecholamine sympathomimetic that acts an an agonist on all alpha- and beta-receptors in the body. Releases NE from neuronal stores. Can be used as an oral treatment for bronchial asthma, as well as for ear and nasal congestion. Can be used as a pressor agent and in opthamology to produce short lasting mydriasis without cycloplegia

What receptors do Ephedrine work on?

What are the clinical uses of Ephedrine?

A direct acting sympathomimetic with primarily alpha-adrenergic stimulating effects. Orally effective only when given in extremely large doses. Used as a pressor agent and in opthamology to produce mydriasis. Used as a nasal spray, but frequently cause a rebound congestion that is worse than the initial congestion

What receptors does Phenylephrine work on?

What drug is known as a non-catecholamine, beta agonist Sympathomimetic?

A drug for the treatment of asthma. Long acting. Fewer cardiac effects than tertubaline. A beta agonist

What is albuterol used for? Is it short or long acting?

A local anesthetic drug that is also a potent inhibitor of NE reuptake I.

What are the subclasses of the Blockers of Adrenergic Nerve Function? (3)

What is the main effect of CNS acting sympatho-inhibitory agents?

What drug is a CNS Acting Sympathoinhibitor?

An imidazoline that is a popular anti-hypertensive drug. A potent alpha₂-adrenoreceptor stimulant that readily penetrates into the CNS. Acts to decrease sympathetic tone to the blood vessels and heart. Enhances vagal outflow to the heart by potentiating baroreceptor mechanisms. Also used for opioid and ethanol withdrawal.

What are the main clinical conditions Clonidine is used to treat?

What is the main effects of Catecholamine Depletion agents?

What drug is a catecholamine depleter?

This drug acts to interrupt the vesicular storage mechanism in sympathetic nerves. It has an antihypertensive effect. Only very large doses cause a sympathomimetic action due to the leakage of NE from the nerve ending. Readily enters CNS and depletes all monoaminergic NTs (NE, EPI, DA, S). Has many side effects that limit its usefulness as an antihypertensive drug (sedation and Parkinson's like syndrome)

What is the main use of Reserpine?

How would alpha-adrenoreceptor blockade manifest clinically?

What are side effects of alpha-adrenoreceptor blockade?

What are the Alpha-adrenoreceptor blockers? (4)

How would beta₁-adrenergic blockade manifest clinically?

What is the effect of beta₂-adrenergic blockade?

What are the major beta-adrenergic blockers? (3)

This drug is a classical antagonist that competes with NE for occupation of alpha-adrenoreceptors. Blocks both subtypes of alpha receptors, but prefers alpha₁s. Short acting. Used as a screening test for pheochromocytoma.

What type of receptors do Phentolamine affect?

What is the main use of Phentolamine?

Does phentolamine have a long or short duration of action?

This drug is a potent alpha-adrenoreceptor antagonist. High preference for alpha₁-receptors. Very long duration of action. Is initially a competitive antagonist but has the ability to irreversibly bind to the receptor. Therefore, after 30-60 min it reverts from a competitive to a non-competitive mechanism.

What type of receptors do Phenoxybenzamine act on?

Does Phenoxybenzamine have a short or long duration of action?

This drug is a selective alpha₁-adrenoreceptor antagonist that does not produce the large reflex tachycardia seen with other alpha antagonists. Therefore, is useful for treating some hypertensive patients. There is some "first dose" effect, however, so initially less drug should be slowly administered

What type of receptors does Prazosin act on?

What can Prazosin be used for?

What is the "first dose" effect seen with Prazosin, and what can be done about it?

This drug is a selective alpha₂-adrenoreceptor antagonist. Clinical use is limited to experimental studies in pts with spinal cord damage. Prevents the CNS hypotensive effects of clonidine and alpha-methyldopa.

What receptors do Yohimbine work on?

What is the clinical use of Yohimbine?

This drug is non-selective (blocks both beta subtypes). Initially used to treat cardiac arrhythmias. Potent local anesthetic. Effective antihypertensive drug. Well absorbed orally, but has potent first pass effect (only ~30% remains in plasma, and ~90% of that is bound to plasma proteins). Dose is therefore difficult to control. Elimination is primarily hepatic.

Which receptors do Propranolol act on?

What is Propranolol primarily used to treat?

This drug is primarily a beta1-adrenoreceptor antagonist. Reduces plasma renin but has less metabolic and bronchial effects. Elimination is primarily hepatic. Side effects include fatigue, dizziness, headache, and insomnia

This drug is primarily a beta1-adrenoreceptor antagonist. Has a longer half-life than Metoproprolol, and produces less CNS side effects. Secreted renally.

Which beta blocker acts on both betas?

WHich beta blocker is secreted renally (other two are hepatic)?

Which Andrenergic receptor antagonists are alpha and beta blockers? (2)

Has both alpha and beta blocking abilities. Nonselective beta antagonist and alpha1 selective blocker. Alpha blocking effect predominates. Long duration. Some first pass effects. Decreases plasma renin. Can be administered orally or i.v. Hepatic metabolism. Effective antihypertensive agent. Postural hypotension is prob in some pts

What is a primary use of Labetalol?

This drug has similar actions as Labetolol but is also a "free radical scavenger" so may protect the heart cells from damage. Approved for use in treating certain pts with congestive heart failure

What is a primary use of Carvedilol?