Overview of Autonomic Drugs and Nervous System Functions

Central nervous system (CNS)

Made up of brain and spinal cord; receives signals from sensory receptors via afferent nerves and processes signals via efferent nerves.

Peripheral nervous system

Composed of efferent and afferent nerves; afferent nerves transmit signals to the spinal cord and brain, while efferent nerves carry impulses from CNS to other body parts.

Cholinergic nerves

Nerves that release acetylcholine; some sympathetic postganglionic fibers release acetylcholine rather than norepinephrine.

Noradrenergic nerves

Nerves that release norepinephrine.

Autonomic nervous system

Regulates certain body functions; composed of adrenergic fibers liberating norepinephrine and cholinergic fibers liberating acetylcholine.

Acetylcholine

Neurotransmitter affecting the CNS.

Norepinephrine

Neurotransmitter affecting the CNS.

Epinephrine

Neurotransmitter affecting the CNS.

Dopamine

Neurotransmitter affecting the CNS.

Glycine

Neurotransmitter affecting the CNS.

Gamma-aminobutyric acid (GABA)

Neurotransmitter affecting the CNS.

Glutamic acid

Neurotransmitter affecting the CNS.

Sympathetic nervous system

Part of the autonomic nervous system; releases norepinephrine and sometimes dopamine.

Parasympathetic nervous system

Part of the autonomic nervous system; releases acetylcholine.

Cholinergic drugs

Drugs causing effects similar to those produced by acetylcholine.

Adrenergic drugs

Drugs causing effects similar to those produced by the adrenergic neurotransmitter.

Anticholinergic agents

Agents that block or inhibit cholinergic activity.

Adrenergic blocking agents

Agents that inhibit the adrenergic system.

Catecholamines

Broad class of drugs including norepinephrine, epinephrine, and dopamine.

Noncatecholamines

Act similarly to catecholamines but are more selective for certain types of receptors.

Sympathomimetics

Drugs that facilitate or mimic actions of the sympathetic nervous system.

Alpha-adrenergic agonists

Drugs that facilitate norepinephrine release.

Beta-adrenergic agonists

Drugs that block norepinephrine uptake.

Direct Acting Alpha1 - Adrenergic Agonists

Drugs like Clonidine and Apraclonidine that act on alpha1-adrenergic receptors.

Direct Acting Beta 1- Adrenergic Agonists

Drugs like Dobutamine that primarily act on beta 1 receptors.

Direct Acting Beta 2- Adrenergic Agonists

Drugs like Albuterol and Terbutaline that act on beta 2 receptors.

Drowsiness

A state of feeling very tired and lethargic.

Cardiac dysrhythmias

Abnormal heart rhythms that can be life-threatening.

Tremors

Involuntary trembling or shaking movements in the body.

Bradycardia

An abnormally slow heart rate, usually below 60 beats per minute.

Sympatholytics

Drugs that reduce or inhibit some or all the actions of the sympathetic nervous system.

Alpha- and Beta-Adrenergic Blocking Agents

Drugs that block both alpha and beta adrenoceptors, resulting in peripheral vasodilation and reduced cardiac rate and contraction.

First Dose Effect

Exaggerated hypotension that can lead to syncope, especially when a patient stands after sitting or lying down.

Orthostatic hypotension

A sudden drop in blood pressure that occurs when a person stands up quickly.

Beta Blockers

Drugs that block beta-1 and/or beta-2 adrenergic receptors.

Prevention of migraines

The use of medications to prevent the onset of migraine headaches.

Thyroid storm

A life-threatening condition that can occur in individuals with untreated or undertreated hyperthyroidism.

Glaucoma

A group of eye conditions that can cause blindness by damaging the optic nerve.

Withdrawal Supersensitivity

Increased sensitivity to a drug following its chronic use and subsequent discontinuation.

Labetalol

A drug that blocks both alpha-1 and beta adrenoceptors, used for hypertension and congestive heart failure.

Cautionary Uses of Beta-Adrenergic Blocking Agents

Conditions where beta blockers should be used cautiously due to potential adverse effects.

Cholinergic Agents

Drugs that stimulate the parasympathetic nervous system and inhibit the enzyme that metabolizes acetylcholine.

SLUDGE

An acronym for the effects of cholinergic agents: Salivation, Lacrimation, Urinary incontinence, Diarrhea, Gastrointestinal cramps, and Emesis.

Muscarinic

Refers to the type of acetylcholine receptor that is stimulated by muscarinic agonists.

Parasympathomimetics

Drugs that mimic the actions of the parasympathetic nervous system.

Direct Acting Cholinergic Agonists

Drugs that directly stimulate cholinergic receptors.

Nicotinic receptor agonists

Drugs that stimulate nicotinic acetylcholine receptors.

Reversible Anticholinesterases

Drugs that inhibit the enzyme acetylcholinesterase in a reversible manner.

Irreversible Anticholinesterases

Drugs that irreversibly inhibit the enzyme acetylcholinesterase.

Succinylcholine

Overstimulation results in depolarizing blockade

Indirect Acting Cholinergic Agonists

Prolongs duration of acetylcholine by binding with and blocking acetylcholinesterase. Indications include Myasthenia Gravis, Glaucoma, Atropine Poisoning

Edrophonium

Reversible indirect acting cholinergic agonist

Donepezil

Reversible indirect acting cholinergic agonist used in Alzheimer's

Echothiophate

Irreversible indirect acting cholinergic agonist used for Glaucoma

Anticholinergic Agents

Block action of acetylcholine in the parasympathetic nervous system. Used to treat Parkinson's disease, GI and ophthalmic disorders, bradycardia, genitourinary disorders

Atropine Sulfate

Used for Cholinesterase poisoning, ACLS: Bradycardia, Pulseless Electrical Activity, and Asystole

Mecamylamine

Nicotinic receptor antagonist - Ganglionic Blocker (NN), a non-depolarizing competitive blocker

Tubocurarine

Neuromuscular blocker, a competitive blocker used for muscle relaxation/paralysis associated with intubation

Anticholinergic effects

Collective symptoms of blurred vision, constipation, urinary retention, dry nose, mouth, and throat

Acetylcholine and norepinephrine

Major neurotransmitters of the autonomic nervous system

Cholinergic receptors

Stimulated to decrease intraocular pressure in glaucoma treatment

Alpha, beta, and dopamine receptors

Subdivisions of the cholinergic side of the nervous system