PHARM 201 Autonomic Pharmacology Medication Study Sheet

Vocabulary flashcards detailing the actions, effects, and clinical uses of autonomic pharmacology medications covered in PHARM 201.

Bethanechol

Action: Nonselective muscarinic receptor agonist. Effect: Stimulates GI and bladder smooth muscle; can cause miosis, secretions, bronchoconstriction and vascular dilation/reflex tachycardia. Clinical use / condition: Post-surgical urinary retention; gastric atony; paralytic ileus.

Pilocarpine

Action: Nonselective muscarinic receptor agonist; crosses the blood-brain barrier. Effect: Contracts ciliary muscle and iris sphincter; causes miosis and increases parasympathetic-type secretions. Clinical use / condition: Glaucoma; Sjogren syndrome/dry mouth.

Nicotine

Action: Nicotinic acetylcholine receptor agonist at autonomic ganglia and neuromuscular receptors. Effect: Initially increases sympathetic and parasympathetic outflow; excessive exposure can lead to receptor desensitization and reduced autonomic outflow. Clinical use / condition: Low-dose nicotine replacement for nicotine use disorder.

Succinylcholine

Action: Depolarizing nicotinic acetylcholine receptor agonist/antagonist at skeletal muscle. Effect: Produces rapid activation followed by skeletal muscle paralysis. Clinical use / condition: Rapid skeletal muscle paralysis for intubation.

Edrophonium

Action: Short-acting reversible acetylcholinesterase inhibitor; does not cross the BBB. Effect: Raises acetylcholine at cholinergic synapses; peripheral parasympathetic effects can occur. Clinical use / condition: Reversal of neuromuscular blockade; treatment of myasthenia gravis.

Neostigmine

Action: Reversible acetylcholinesterase inhibitor of intermediate duration; does not cross the BBB. Effect: Raises peripheral acetylcholine; parasympathetic effects predominate. Clinical use / condition: Reversal of neuromuscular blockade; treatment of myasthenia gravis.

Physostigmine

Action: Reversible acetylcholinesterase inhibitor; tertiary amine that crosses the BBB. Effect: Raises acetylcholine in both CNS and peripheral synapses. Clinical use / condition: Compensation/treatment for atropine or scopolamine overdose; also increases intestinal/bladder motility.

Organophosphates (e.g., DFP/isofluorophate, sarin)

Action: Long-acting to essentially irreversible acetylcholinesterase inhibitors that phosphorylate the enzyme. Effect: Causes marked acetylcholine accumulation: secretions, GI effects, bronchoconstriction, muscle twitching/weakness/paralysis and CNS toxicity. Clinical use / condition: Primarily toxicology/nerve-agent exposure; isofluorophate is also discussed as an indirect cholinergic glaucoma treatment.

Atropine

Action: Nonselective muscarinic receptor antagonist; crosses the BBB slowly. Effect: Increases heart rate, dilates pupils, reduces secretions, decreases GI/bladder activity; CNS toxicity at high doses. Clinical use / condition: Bradycardia; mydriasis; antidote for muscarinic effects of cholinesterase-inhibitor poisoning.

Scopolamine

Action: Nonselective muscarinic receptor antagonist; readily crosses the BBB. Effect: Reduces cholinergic signaling in the CNS and periphery; can cause dry mouth, tachycardia, mydriasis and CNS effects. Clinical use / condition: Motion sickness (transdermal patch); reduction of secretions/amnesia during procedures.

Ipratropium

Action: Nonselective muscarinic receptor antagonist; quaternary amine with poor membrane/BBB penetration. Effect: Bronchodilation and reduced bronchial secretions with low systemic absorption when inhaled. Clinical use / condition: Asthma or COPD.

Pralidoxime (2-PAM)

Action: Regenerates/reactivates acetylcholinesterase inhibited by organophosphates before irreversible aging. Effect: Restores acetylcholinesterase activity and reduces excessive acetylcholine signaling. Clinical use / condition: Antidote for organophosphate poisoning.

Epinephrine

Action: Adrenergic agonist at alpha-1, alpha-2, beta-1 and beta-2 receptors (dose dependent). Effect: Raises cardiac rate/contractility via beta-1, bronchodilates via beta-2, and at higher doses vasoconstricts via alpha-1. Clinical use / condition: Anaphylaxis; cardiac arrest/cardiac stimulation; acute bronchospasm; historically glaucoma.

Norepinephrine

Action: Adrenergic agonist with strong alpha-1/alpha-2 and beta-1 activity and little beta-2 activity. Effect: Strong vasoconstriction plus cardiac stimulation; net effect is a major increase in blood pressure. Clinical use / condition: Severe hypotension/hypotensive crisis, including severe septic shock.

Isoproterenol

Action: Nonselective beta-adrenergic agonist (beta-1 and beta-2). Effect: Increases heart rate/contractility and relaxes bronchial and vascular smooth muscle. Clinical use / condition: Certain cardiac conduction dysfunctions; historically asthma.

Phenylephrine

Action: Selective alpha-1 adrenergic agonist. Effect: Constricts arteries and veins, raises peripheral resistance/BP; may cause reflex slowing of heart rate; constricts nasal mucosal vessels. Clinical use / condition: Hypotension; topical nasal decongestion; mydriasis/local vasoconstriction.

Prazosin

Action: Selective alpha-1 adrenergic antagonist. Effect: Relaxes arteries and veins, lowers peripheral resistance/BP, reduces preload; relaxes bladder outlet/urethral smooth muscle. Clinical use / condition: Hypertension; short-term reduction of cardiac workload in CHF; improved urine flow in BPH.

Propranolol

Action: Nonselective beta-adrenergic antagonist (beta-1 and beta-2 blocker). Effect: Decreases cardiac rate/contractility and reduces cardiac oxygen demand. Clinical use / condition: Hypertension; angina; arrhythmias; migraines, glaucoma and anxiolytic use.

Ephedrine

Action: Mixed adrenergic drug: direct alpha/beta stimulation plus increased norepinephrine release in PNS and CNS. Effect: Produces sympathetic stimulation, including increased blood pressure and CNS stimulation. Clinical use / condition: Cold/decongestant-type use; historical weight-loss/performance uses.

Pseudoephedrine

Action: Ephedrine stereoisomer with reduced tachycardia/CNS effects; increases norepinephrine release. Effect: Constriction of nasal mucosal vessels and sympathetic stimulation. Clinical use / condition: Nasal decongestant.

Amphetamine

Action: Indirect sympathomimetic taken up into nerve endings, increasing norepinephrine release; also increases CNS NE, dopamine and 5-HT release. Effect: CNS stimulation and increased cardiac output/BP; can cause arrhythmias and dependence. Clinical use / condition: Narcolepsy; ADHD and anorexiant use.

Methamphetamine

Action: Grouped with amphetamine in the lecture summary as increasing norepinephrine release in sympathetic NS and CNS. Effect: Strong sympathetic/CNS stimulation with high addiction liability and cardiovascular/CNS adverse effects. Clinical use / condition: ADHD, narcolepsy and anorexiant use.

Tyramine

Action: Indirect sympathomimetic that releases norepinephrine from sympathetic nerve endings; does not penetrate the BBB. Effect: Can produce substantial adrenergic stimulation when MAO is inhibited. Clinical use / condition: No clinical use; important food/drug interaction with MAO inhibitors.

Cocaine

Action: Indirect adrenergic stimulant that blocks norepinephrine reuptake; also blocks dopamine and 5-HT reuptake and blocks Na channels. Effect: Increases heart rate/BP and causes vasoconstriction; also produces local anesthesia. Clinical use / condition: Local anesthetic and vasoconstrictor for mucosal application during ENT surgery.