OIA1013 (TERMS) ADRENERGIC ANTAGONISTS

Adrenergic antagonists

Compounds inhibiting adrenaline and noradrenaline actions.

Adrenoceptor antagonists

Drugs blocking adrenergic receptors' activity.

α-Adrenoreceptors

Two types: α1 and α2 receptors.

β-Adrenoblockers

Divided into β1, β2, and β3 blockers.

First-generation β blockers

Nonselective β blockers used historically.

Second-generation β blockers

Cardioselective β1 blockers for heart issues.

Third-generation β blockers

New β blockers with vasodilator properties.

Peripheral presynaptic anti-adrenergics

Medications targeting presynaptic adrenergic neurons.

Mechanism of action (MOA)

Inhibits catecholamine release from adrenergic neurons.

Fight-or-flight response

Physiological reaction blocked by adrenergic antagonists.

Metyrosine

Inhibits tyrosine hydroxylase to reduce catecholamines.

Pheochromocytoma treatment

Use of metyrosine for excessive sympathetic stimulation.

Tyrosine hydroxylase

Enzyme converting tyrosine to DOPA in synthesis.

Reserpine

Inhibits norepinephrine storage for hypertension treatment.

VMAT

Vesicular monoamine transporter for neurotransmitter storage.

Guanethidine

Antihypertensive agent depleting norepinephrine stores.

Norepinephrine synthesis

Process of producing norepinephrine in neurons.

Norepinephrine storage

Sequestering norepinephrine in presynaptic vesicles.

Norepinephrine release

Discharge of norepinephrine into synaptic cleft.

Adverse effects

Negative side effects associated with adrenergic drugs.

Cardiovascular effects

Impact on heart rate and blood pressure.

Digestion effects

Altered digestive processes due to adrenergic antagonists.

Bronchodilation

Widening of air passages, affected by adrenergics.

Guanethidine

Blocks norepinephrine release from presynaptic neurons.

Alpha Blockers

Prevent stimulation of α-adrenergic receptors by catecholamines.

Beta Blockers

Prevent stimulation of β-adrenergic receptors by catecholamines.

α-Adrenergic Antagonists

Drugs that block α-adrenergic receptors.

β-Adrenergic Antagonists

Drugs that block β-adrenergic receptors.

Vasodilation

Dilation of blood vessels due to α-receptor blockade.

Heart Rate Decrease

Effect of β-receptor blockade on heart rate.

α-1 Receptors

Located on blood vessel walls; cause vasoconstriction.

α-2 Receptors

Regulate neurotransmitter release; inhibit norepinephrine release.

Nonselective α-Blockers

Block both α-1 and α-2 adrenergic receptors.

Selective α-1 Blockers

Target only α-1 adrenergic receptors.

Selective α-2 Blockers

Target only α-2 adrenergic receptors.

Phenoxybenzamine

Long-acting, irreversible α-blocker for hypertension.

Phentolamine

Short-acting, reversible α-blocker for hypertensive emergencies.

Pheochromocytoma

Tumor causing excess catecholamine production; treated with blockers.

Adverse Effects

Include dizziness, miosis, and postural hypotension.

Reflex Tachycardia

Increased heart rate due to blood pressure drop.

Benign Prostatic Hyperplasia (BPH)

Condition treated by selective α-1 blockers.

α-1 Blocker Suffix

Selective α-1 blockers end with '-osin'.

Doxazosin

Selective α-1 blocker used for hypertension and BPH.

Tamsulosin

Selective α-1 blocker primarily for BPH treatment.

Terazosin

Selective α-1 blocker used for hypertension and BPH.

Miosis

Constriction of pupils; a potential side effect.

Doxazosin

Selective α-1 antagonist for hypertension and BPH.

Tamsulosin

Targets α-1A receptors, aiding urinary flow.

Prazosin

α-1 antagonist used for hypertension treatment.

Terazosin

α-1 antagonist for hypertension and urinary symptoms.

Mild to moderate hypertension

Blood pressure condition manageable with medication.

Benign prostatic hyperplasia

Prostate enlargement causing urinary difficulties.

α-1 receptors

Receptors mediating vasoconstriction and smooth muscle contraction.

First dose hypotension

Significant blood pressure drop after initial medication dose.

Intra-operative floppy iris syndrome

Complication during cataract surgery linked to α-blockers.

Sexual dysfunction

Common side effect of α-1 antagonists.

Mirtazapine

Presynaptic α2-antagonist enhancing noradrenergic neurotransmission.

Yohimbine

α2-antagonist used for erectile dysfunction treatment.

Rauwolscine

Selective α2-antagonist with similar effects to Yohimbine.

Atipamezole

α2-antagonist used in veterinary medicine.

Idazoxan

Selective α2-antagonist with limited clinical use.

Sympathetic nervous system

Part of the autonomic nervous system stimulating fight-or-flight.

Norepinephrine release

Increased by α2-antagonists, enhancing sympathetic activity.

β1 receptors

Receptors increasing heart rate and contractility.

Renin release

Stimulated by β1 receptors, regulating blood pressure.

β2 receptors

Receptors causing vasodilation and increased blood flow.

β-blockers

Drugs treating cardiovascular diseases by blocking β receptors.

First-generation β-blockers

Nonselective, blocking both β1 and β2 receptors.

Second-generation β-blockers

Selective for β1 receptors, minimizing β2 effects.

Adverse effects of Mirtazapine

Includes anxiety, increased appetite, and fatigue.

Third-generation β-blockers

Nonselective, vasodilators via α1-blockade.

First generation β-blockers

Includes propranolol, nadolol, timolol, and more.

Indications for β-blockers

Used for tachycardia, hypertension, and heart failure.

Mechanism of Action (MOA)

Blocks β1 receptors, reducing heart rate and contractility.

Renin release

Decreased by β1 blockade in juxtaglomerular cells.

Angiotensin II

Decreased by reduced renin from β1 blockade.

Aldosterone

Lowered due to decreased angiotensin II levels.

Vasoconstriction

Caused by β2-receptor blockade in blood vessels.

Propranolol

Lipid-soluble, penetrates blood-brain barrier.

Migraine prevention

Propranolol alters cerebral blood flow.

Bronchoconstriction

Caused by β2-blockade in lungs, contraindicated in asthma.

Gastrointestinal motility

Increased by β2-receptor blockade.

Intraocular pressure

Decreased by timolol in glaucoma treatment.

Glucose release

Reduced from liver due to β-blocker action.

Hypoglycemia risk

β-blockers may mask symptoms in diabetes patients.

Common side effects

Include bradycardia, confusion, fatigue, and dizziness.

COPD contraindication

β-blockers can worsen symptoms in COPD patients.

Abrupt withdrawal risks

May cause rebound tachycardia and hypertension.

Catecholamine effects

Blunted by β-blockers, increasing hypoglycemia risk.

Erectile dysfunction

Potential side effect of β-blocker therapy.

Timolol

Topical treatment for glaucoma, reduces intraocular pressure.

Diabetes caution

Monitor for hypoglycemic episodes with β-blockers.

Beta Blockers

Medications that block β-adrenergic receptors.

Second Generation Beta Blockers

Selective for β1 adrenergic receptors, cardioselective.

Atenolol

A second-generation β-blocker, cardioselective.

Metoprolol

Commonly used second-generation β-blocker.

Bisoprolol

Cardioselective β-blocker for hypertension treatment.

Esmolol

Short-acting β1 selective blocker for acute situations.

Acebutolol

Partial β1 agonist with some β-blocking activity.

Cardioselective

Preferentially blocks β1 receptors, minimizing bronchoconstriction.