Pharmacology

Direct sympathomimetics β2 > β1 Applications: - Albuterol for acute asthma or COPD- Salmeterol for long-term asthma or COPD management- Terbutaline for acute bronchospasm in asthma and tocolysis

Direct sympathomimetic β1 > β2 > α Applications:- Heart failure (HF)- Cardiogenic shock (inotropic > chronotropic)- Cardiac stress testing

Direct sympathomimetic D1 = D2 > β > α Applications:- Unstable bradycardia- HF- Shock- Inotropic and chronotropic effects at lower doses due to β effects; vasoconstriction at high doses due to α effects

β > α Applications:- Anaphylaxis- Asthma- Open-angle glaucoma- α effects predominate at high doses- Significantly stronger effect at β2-receptor than norepinephrine

D1 Applications:- Postoperative hypertension- Hypertensive crisis- Vasodilator (coronary, peripheral, renal, and splanchnic)- Promotes natriuresis- Can cause hypotension and tachycardia

Direct sympathomimetic β1 = β2 Applications:- Electrophysiologic evaluation of tachyarrhythmias- Can worsen ischemia- Has negligible α effect

Direct sympathomimetic α1 Applications: - Autonomic insufficiency and postural hypotension- May exacerbate supine hypertension

Direct sympathomimetic β3 Application:- Urinary urge incontinence- Overactive bladder

α1 > α2 > β1 Applications:- Hypotension- Septic shock

Direct sympathomimetic α1 > α2 Applications:- Hypotension (vasoconstrictor)- Ocular procedures (mydriatic)- Rhinitis (decongestant)- Ischemic priapism Adverse effect: Tachyphylaxis- Decreased production of endogenous norepinephrine due to negative feedback mechanism, resulting in relative vasodilation and subsequent edema and congestion. → Rebound rhinorrhea with use ≥3 days.

Indirect general sympathomimetic agonst, reuptake inhibitor - Causes vasoconstriction and local anesthesia - Caution when giving β-blockers if cocaine intoxication is suspected (can lead to unopposed α1 activation → extreme hypertension, coronary vasospasm).

Indirect general agonist, releases stored catecholamines - Nasal decongestion (pseudoephrine)- Urinary incontinence- Hypotension

Sympatholytics (α2-agonists) Applications:- Hypertensive urgency (limited situations)- ADHD- Tourette syndrome- Symptom control in opioid withdrawal Adverse effects: CNS depression, bradycardia, hypotension, respiratory depression, miosis, rebound hypertension with abrupt cessation

Sympatholytic (α2-agonist) Application: Hypertension in pregnancy Adverse effects:- Direct Coombs ⊕ hemolysis- Drug-induced lupus

Sympatholytic (α2-agonist) Application: Relief of spasticity Adverse effects: Hypotension, weakness, xerostomia

Irreversible, nonselective α-blocker Applications:- Pheochromocytoma (used preoperatively) to prevent catecholamine (hypertensive) crisis Adverse effects:- Orthostatic hypotension- Reflex tachycardia

Nonselective α-blocker Applications:- Reversible (vs phenoxybenzamine)- Give to patients on MAO inhibitors who eat tyramine-containing foods and for severe cocaine-induced hypertension Adverse effects:- Orthostatic hypotension- Reflex tachycardia

α1-selective blocker Applications:- Urinary symptoms of BPH- PTSD (prazosin)- Hypertension (except tamsulosin) Adverse effects:- 1st-dose orthostatic hypotension- Dizziness- Headache

α2-selective blocker Application: Depression Adverse effects:- Sedation- ↑ serum cholesterol- ↑ appetite

Angina pectoris: ↓ heart rate and contractility, resulting in ↓ O2 consumption Glaucoma: ↓ production of aqueous humor- Timolol Heart failure: ↓ mortality- Bisoprolol, carvedilol, metoprolol Hypertension: ↓ cardiac output, ↓ renin secretion (due to β1-receptor blockade on JGA cells) Hyperthyroidism: Symptom control (↓ heart rate, ↓ tremor), thyroid storm- Propanolol Hypertrophic cardiomyopathy: ↓ heart rate → ↑ filling time, relieving obstruction Myocardial infarction: ↓ mortality Supraventricular tachycardia: ↓ AV conduction velocity (class II antiarrhythmic)- Metoprolol, esmolol Variceal bleeding: ↓ hepatic venous pressure gradient and portal hypertension (prophylactic use)- Nadolol, propanolol, carvedilol Adverse effects: Erectile dysfunction, cardiovascular (bradycardia, AV block, HF), CNS (seizures, sleep alterations), dyslipidemia (metoprolol), and asthma/COPD exacerbations.

β1-selective antagonists (β1 > β2) – acebutolol (partial agonist), atenolol, betaxolol, bisoprolol, esmolol, metoprolol- Selective antagonists mostly go from A to M (β1 with 1st half of alphabet) Nonselective antagonists (β1 = β2) – nadolol, pindolol (partial agonist), propanolol, timolol- Nonselective antagonists mostly go from N to Z (β2 with 2nd half of alphabet) Nonselective α- and β-antagonists – carvedilol, labetalol- Nonselective α- and β-antagonists have modified suffixes (instead of "-olol") Nebivolol combines cardiac-selective β1-adrenergic blockade with stimulation of β3-receptors (activate nitric oxide synthase in the vasculature and ↓ SVR).

Muscarinic antagonist

α-adrenergic agonist - Effective decongestant Adverse effect: Tachyphylaxis