Neuropharmacology Lecture Review

Flashcards covering key terminology, drug classifications, mechanisms of action, and clinical uses explained in the Neuropharmacology lecture notes, focusing on the Peripheral Nervous System.

Neuropharmacology

The study of drugs that alter processes controlled by the nervous system.

Peripheral Nervous System (PNS)

One of the two main divisions of the nervous system, along with the Central Nervous System (CNS).

Axonal conduction

A site of action for neuropharmacological agents that is not selective (e.g., local anesthetics).

Synaptic transmission

A highly selective site of action for neuropharmacological agents, where drugs alter transmission to produce specific responses.

Receptor

The ability of a neuron to influence the behavior of another cell depends on its ability to alter receptor activity on the target cell.

Target cell

Another neuron, muscle, or secretory gland whose activity is influenced by a neuron altering its receptor activity.

Drug Selectivity

One of the most desirable qualities of a drug, allowing it to produce specific responses by interacting with particular receptors.

Central Nervous System (CNS)

Comprises the brain and spinal cord.

Somatic Motor System

A division of the Peripheral Nervous System that controls muscles under voluntary control.

Parasympathetic Nervous System

A division of the autonomic nervous system associated with 'rest and digest' functions, conserving energy and regulating digestion, excretion, and vision.

Sympathetic Nervous System

A division of the autonomic nervous system associated with 'fight-or-flight' reactions, regulating the cardiovascular system, body temperature, and mobilizing stored energy.

Piloerection

The erection of hair, promoted by the sympathetic nervous system.

Dual innervation

The state where most structures under autonomic control receive nerves from both the sympathetic and parasympathetic divisions, often with opposing or complementary effects.

Baroreceptor reflex

The most important feedback loop of the Autonomic Nervous System, regulating blood pressure and located in the carotid sinus and aortic arch.

Autonomic tone

The basal control provided to an organ by only one division of the ANS (PNS for most organs, SNS for the vascular system).

Ganglion (PNS/SNS)

The junction (synapse) between the pre-ganglionic and post-ganglionic neurons in the pathways leading from the spinal cord to innervated organs.

Pre-ganglionic neurons

Neurons that go from the spinal cord to the parasympathetic or sympathetic ganglia.

Post-ganglionic neurons

Neurons from the ganglia to the effector organs.

Adrenal medulla

A feature of the sympathetic nervous system that influences the body by releasing epinephrine into the bloodstream.

Acetylcholine (ACh)

A principle neurotransmitter of the Peripheral Nervous System, released by preganglionic neurons of both PNS/SNS, postganglionic PNS neurons, and motor neurons to skeletal muscles.

Norepinephrine (NE)

A principle neurotransmitter of the Peripheral Nervous System, released by most postganglionic neurons of the sympathetic nervous system.

Epinephrine (Adrenalin)

A principle neurotransmitter of the Peripheral Nervous System, primarily released by the adrenal medulla.

Cholinergic receptors

Receptors in the Peripheral Nervous System that are mediated by acetylcholine.

Adrenergic receptors

Receptors in the Peripheral Nervous System that are mediated by epinephrine and norepinephrine.

Nicotinic N receptors

Cholinergic receptor subtype located on the cell bodies of all postganglionic neurons (PNS/SNS) and on cells of the adrenal medulla, promoting ganglia transmission and epinephrine release.

Nicotinic M receptors

Cholinergic receptor subtype located on skeletal muscle, mediating skeletal muscle contraction.

Muscarinic receptors

Cholinergic receptor subtype located on all organs regulated by the parasympathetic nervous system and on sweat glands, activating the PNS and sympathetic sweat glands.

Alpha1 receptors

Adrenergic receptor subtype whose activation causes vasoconstriction, ejaculation, contraction of bladder neck and prostate, and pupil dilation (mydriasis).

Beta1 receptors

Adrenergic receptor subtype primarily found in the heart (increasing heart rate and contractility) and kidneys (releasing renin).

Beta2 receptors

Adrenergic receptor subtype whose activation causes bronchial dilation, relaxation of uterine muscle, vasodilation, and glycogenolysis.

Dopamine receptors

A specific adrenergic receptor subtype whose activation dilates renal blood vessels, increases renal perfusion, and prevents renal failure.

Catecholamines

A term sometimes used to refer to adrenergic neurotransmitters like epinephrine, norepinephrine, and dopamine, which cannot be used orally due to rapid destruction by enzymes.

Agonists

Drugs that stimulate receptors.

Antagonists

Drugs that inhibit receptors.

Cholinergic drugs

Drugs that influence the activity of cholinergic receptors, either by mimicking or blocking acetylcholine actions, or by preventing its breakdown.

Anticholinergic drugs

Drugs that block the action of acetylcholine, typically at muscarinic or nicotinic receptors.

Cholinesterase inhibitors

Drugs that prevent the breakdown of acetylcholine by acetylcholinesterase, thereby prolonging and intensifying acetylcholine's action.

SLUDGE symptoms

An acronym for Salivation, Lacrimation, Urination, Defecation, Gastrointestinal cramps, and Emesis, which are signs and symptoms of cholinergic crisis or overdose.

Anticholinergic effects

A constellation of symptoms including 'Red as a beet' (flushed skin), 'Dry as a bone' (dry mouth, eyes, skin), 'Blind as a bat' (dilated pupils, blurred vision), 'Mad as a hatter' (confusion), 'Hot as a hare' (fever), and 'Full as a flask' (urinary retention).

Bethanechol (Urecholine)

A direct-acting muscarinic agonist (cholinergic drug) used to treat urinary retention, GERD, ileus, and postop abdominal distention.

Atropine

A muscarinic antagonist (anticholinergic drug) that blocks acetylcholine at muscarinic receptors, used for pre-anesthesia, bradycardia, muscarinic agonist poisoning, and asthma.

Myasthenia Gravis

A chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body, often treated with cholinesterase inhibitors.

Neostigmine (Prostigmin)

A reversible cholinesterase inhibitor used to increase muscle strength in myasthenia gravis.

Cholinergic crisis

An overdose of cholinesterase inhibitors, leading to excessive acetylcholine accumulation at muscarinic and neuromuscular junctions, causing skeletal muscle paralysis and severe muscarinic overstimulation; treated with atropine.

Myasthenia crisis

An underdose of cholinesterase inhibitors in myasthenia gravis, leading to extreme muscle weakness, especially affecting the respiratory diaphragm; treated with a cholinesterase inhibitor (e.g., neostigmine) and respiratory support.

Neuromuscular Blocking Agents

Drugs that block acetylcholine from activating nicotinicM receptors on skeletal muscles, causing muscle relaxation/paralysis, commonly used during surgery, intubation, and mechanical ventilation.

Succinylcholine (Anectine)

A depolarizing neuromuscular blocking agent that causes constant depolarization of muscle end plates, leading to paralysis; rapid and short-acting, used for intubation, and may trigger malignant hyperthermia.

Conscious sedation

A critical nursing action for patients receiving neuromuscular blocking agents to ensure they do not experience awareness while paralyzed.

Albuterol

A beta2 agonist (non-catecholamine) primarily used for bronchodilation in asthma.

Epinephrine (Adrenalin, EpiPen)

An adrenergic agonist that activates Alpha1, Alpha2, Beta1, and Beta2 receptors, used for asystole, heart block, and anaphylactic shock.

Anaphylactic shock treatment (Epinephrine)

Epinephrine reverses severe anaphylactic manifestations via Alpha1 (vasoconstriction), Beta1 (increased heart rate), and Beta2 (airway opening) receptor activation.

Beta-adrenergic blocking agent (Beta Blocker)

Drugs that block beta receptors, either nonselectively (beta1 and beta2, e.g., propranolol) or cardioselectively (beta1 only, e.g., metoprolol).

Alpha-adrenergic blocking agent (Alpha Blocker)

Drugs that block alpha receptors, either nonselectively (alpha1 and alpha2, e.g., phentolamine) or selectively (alpha1 only, e.g., prazosin).

Prazosin (Minipress)

A selective alpha1 blocker used to treat essential hypertension and benign prostatic hyperplasia (BPH) by causing vasodilation.

Orthostatic hypotension

A common adverse effect of alpha1 adrenergic antagonists, caused by widespread vasodilation upon standing.

Clonidine (Catapres)

A centrally acting alpha2 agonist that selectively stimulates alpha2 receptors in the brain, resulting in decreased stimulation of peripheral adrenergic receptors to treat hypertension.

Methyldopa (Aldomet)

A centrally acting alpha2 agonist (after transformation in the brain) used for hypertension, including in pregnancy, but can cause drug-induced hepatitis.