Autonomic & Neuromuscular

Autonomic & Neuromuscular

Atenolol Atropine Dobutamine Edrophonium Epinephrine Phenoxybenzamine Phentolamine Phenylephrine Pilocarpine

Pralidoxime Propranolol Pseudoephrine Pyridostigmine Rocuronium Sildenafil Succinylcholine Tamsulosin Terazosin

Atenolol

Sympatholytic, antihypertensive

Β1 receptor antagonist

β1 receptor antagonist

Angina Post MI Hypertension

Bronchoconstriction w/ high doses b/c β1 blockade

Additive hypotension w/ nitrates

Atropine

Anticholinergic Muscarinic receptor

antagonist

Muscarinic receptor blocker

Bradycardia IBS Anticholinesterase poisoning Antisecretory agent

Mydriasis & cycloplegia Warm, dry, flushed skin Tachycardia Delirium Hallucinations

Dobutamine

Sympathomimetic, cardiac stimulant

β1 receptor agonist

Selective β1 receptor agonist β1 > β2 > α1

Cardiac contractility & output Acute heart failure Cardiogenic shock

Synergistic on cardiac output w/ nitroprusside

Tachycardia Arrhythmia

Edrophonium

Diagnostic agent Cholinesterase

inhibitor

Reversible cholinesterase inhibitor

Dx myasthenia gravis

Muscarinic effects Miosis Salivation

Epinephrine

Sympathomimetic, bronchodilator, vasopressor

Nonselective adrenergic agonist

Activates α & β receptors ↑ IP3 & cAMP

α1 – vasoconstrict & ↑ BP β1 – ↑ HR, conduction, &

contractility β2 – vasodilate, ↓ BP,

bronchodilate

Cardiac arrest, V fib Shock, asthma COPD

HTN Tachycardia Ischemia Hyperglycemia

Phenoxybenzamine

Vasodilator Irreversible α receptor

antagonist

α receptor antagonist α1 > α2

Presurgical Tx of HTN d/t pheochromocytoma

Postural hypotension

Hypotension w/ β blockers & Ca channel blockers

Phentolamine

Vasodilator α receptor antagonist

Blocks α1 & α2 receptors

Control BP during surgical removal of pheochromocytoma

IV admin only

Hypotension

Severe hypotension w/ Epi

Phenylephrine

Vasocontrictor, decongestant Selective α1 receptor

agonist

Activates α1 receptor Increase IP3 causing

contraction of vascular smooth m.

Nasal & ocular decongestant Dilate pupil for opthalmoscopy Mydriasis w/o cycloplegia

Paralysis of accommodation

Rebound nasal congestion HTN

MAOI cause severe HTN

Pilocarpine

Antiglaucoma, sialogogue Muscarinic receptor

agonist

Activates muscarinic receptors in ciliary m. & salivary gland

Sjogren’s syn Glaucoma

• Ciliary m. ↑ aqueous humor

Xerostomia• Salivary gland ↑ salivation

Miosis Blurred vision

Accommodative spasm

Pralidoxime

Organophosphate antidote Cholinesterase reactivator

Binds phosphorous & breaks organophosphate bond w/ cholinesterase

Organophosphate toxicity Reverses muscle weakness

Propranolol

Sympatholytic, antihypertensive Nonselective β receptor

antagonist

Blocks β1 & β2 receptors

Angina HTN Benign tremor Migraine prophylaxis thyrotoxicosis Post-MI

Highly lipophilic CNS effects

Bronchoconstriction Inhibits glycogenolysis Nightmares & depression

Pseudoephedrine

Decongestant Indirect/direct-acting

adrenergic receptor agonist

↑ release NE directly activates adrenergic receptors causing vasoconstriction & cardiac stim.

Allergic & viral rhinitis

Tachycardia CNS stim. ↑ BP

MAOI cause severe HTN

Pyridostigmine

Antimyasthenic Cholinesterase inhibitor,

cholinergic agonist

Reversibly inhibits cholinesterase

Tx myasthenia gravis Reverse nondepolarizing

NM blockers

Muscarinic effects Miosis Salivation

Prolongs effects of succinylcholine

Rocuronium

Paralytic agent Nondepolarizing NM

blockade

Blocks nicotinic receptors in skeletal m.

Skeletal m. relaxation for intubation, surgery, ECT

Effects reversed by neostigmine & edrophonium

Respiratory m. paralysis Apnea

Sildenafil

Vasodilator Phosphodiesterase

inhibitor

Inhibits type 5 phosphodiesterase & degradation of cGMP vasodilation in corpus

cavernosum d/t Ach release from sacral PNS neurons

Erectile dysfunction

HA Nasal congestion Back pain Visual disturbances

Succinylcholine

Paralytic agent Depolarizing NM blockade

Binds nicotinic receptors causing prolonged depolarization of skeletal m. & paralysis

Skeletal m. relaxation for intubation & surgery

Transient m. fasciculations

Respiratory m. paralysis Apnea

Tamsulosin

Urologic agent Uroselective α1

receptor antagonist

Blocks α1A receptors in prostate

Tx urinary outflow obstruction d/t prostatic hyperplasia

Dizziness HA Postural hypotension

Cimetidine increases blood levels & effects

Terazosin

Antihypertensive, urologic agent

Selective α1 receptor antagonist

Blocks α1 receptors

HTN Outflow obstruction d/t

prostate hyperplasia

1st dose syncope