2. Basic Science Concepts Flashcards
Define Substrate (or Ligand)
A substance that creates a signal or produces an effect by binding to a receptor, enzyme, or transporter
Define Endogenous
A substance that is produced by the body (such as a naturally-produced substrate)
Define Exogenous
A substance that is produced outside of a body (such as a drug or other chemical)
Define Agonist
A substance that combines with a receptor to initiate a reaction. Can be endogenous or exogenous (mimicking an endogenous substrate)
Define Antagonist
A substance that reduces or blocks a reaction. Can be endogenous or exogenous.
Define Induction
When a substance increases the activity of an enzyme
Define Inhibition
When a substance decreases or blocks the activity of an enzyme
The central nervous system (CNS) includes 2 parts: __ and ___
brain and the spinal cord
The peripheral nervous system includes 2 main systems. Explain both.
Somatic - voluntary (muscle)
Autonomic - involuntary (GI, CV)
____ is the primary neurotransmitter involved in the somatic nervous system. It is released in response to neuron signals and binds to __ receptors in ___ muscles to affect muscle movement.
ACh (acetylcholine)
Nicotinic receptors
Skeletal muscles
____ is known as the “rest and digest” system
Parasympathetic nervous system
How does the parasympathetic nervous system work?
Releases ACh, which binds to muscarinic receptors throughout the body
Results in physiologic response known as SLUDD (salivation, lacrimation, urination, defecation, and digestion)
What happens when parasympathetic nervous system is activated?
SLUDD = Salivation, lacrimation, urination, defecation, and digestion
____ is known as the “fight or flight” system
Sympathetic nervous system
How does the sympathetic nervous system work?
Releases Epi or NE which acts on adrenergic receptors (alpha-1, beta-1, and beta-2) in CV and respiratory systems
Results in increased BP, HR, and bronchodilation
What happens when sympathetic nervous system is activated?
Increased BP, HR, and bronchodilation
Stimulation of beta-2 receptors in GI tract = increased glucose production to provide muscles with oxygen and energy
Where do you typically find alpha-1 receptors? beta-1? beta-2?
Alpha-1 = smooth muscles, including blood vessels
Beta-1 = heart (1 = 1 heart)
Beta-2 = lungs (2 = 2 lungs)
Vasopressors, such as __ and ___, stimulate multiple receptors, including ___ and ___, leading to increased vasoconstriction, HR, and BP.
Epi, NE
alpha-1 and beta-1
Clonidine is a central acting ___ adrenergic agonists. What does it do?
alpha-2
Stimulates presynaptic alpha-2 receptors located in the brain, decrease in overall sympathetic output (NT release) –> vasodilation (decreased BP) and decrease in HR
Endogenous substrate of muscarinic receptors?
ACh
Endogenous substrate of nicotinic receptors?
ACh
Endogenous substrate of alpha-1 receptors (mainly peripheral)?
Epi, NE
Endogenous substrate of alpha-2 receptors (mainly brain; central)?
Epi, NE
Endogenous substrate of beta-1 receptors (mainly heart)?
Epi, NE
Endogenous substrate of beta-2 receptors (mainly lungs)?
Epi
Endogenous substrate of dopamine receptors?
Dopamine (DA)
Endogenous substrate of serotonin receptors?
Serotonin (5-HT)
Action of muscarinic agonist?
Increase SLUDD
Action of muscarinic antagonists?
Decrease SLUDD
Action of nicotinic agonist?
Increase HR, BP
Action of nicotinic antagonist?
Neuromuscular blockade
Action of Alpha-1 agonist?
Smooth muscle vasoconstriction, increase BP
Action of Alpha-1 antagonist?
Smoot muscle vasodilation, decrease BP
Action of Alpha-2 agonist?
Decrease release of Epi and NE, decrease BP/HR
Action of Alpha-2 antagonist?
Increase BP, HR
Action of beta-1 agonist?
Increase myocardial contractility, CO, HR
Action of beta-1 antagonist?
Decrease CO, HR
Action of beta-2 agonist?
Bronchodilation
Action of beta-2 antagonist?
Bronchoconstriction
Action of dopamine agonist?
Many, including renal, cardiac, and CNS effects
Action of dopamine antagonist?
Many, including renal, cardiac, and CNS effects
Action of serotonin agonist?
Many, including platelet, GI, and psychiatric effects
Action of serotonin antagonist?
Many, including platelet, GI, and psychiatric effects
Muscarinic agonist drug examples
Pilocarpine, bethanechol
Muscarinic antagonist drug examples
Atropine, oxybutynin
Nicotinic agonist drug examples
Nicotine
Nicotinic antagonist drug examples
Neuromuscular blockers (e.g. rocuronium)
Alpha-1 agonist drug examples
Phenylephrine, dopamine (dose-dependent)
Alpha-1 antagonist drug examples
Alpha-1 blockers (e.g. doxazosin, carvedilol, phentolamine)
Alpha-2 agonist drug examples
Clonidine, brimonidine (ophthalmic, for glaucoma)
Alpha-2 antagonist drug examples
Ergot alkaloids, yohimbine
Beta-1 agonist drug examples
Dobutamine, isoproterenol, dopamine (dose-dependent)
Beta-1 antagonist drug examples
beta-1 selective blockers (e.g. metoprolol) and non-selective beta-blockers (e.g. propranolol, carvedilol)
Beta-2 agonist drug examples
Albuterol, terbutaline, isoproterenol
Beta-2 antagonist drug examples
Non-selective beta-blockers (e.g. propranolol, carvedilol)
Dopamine agonist drug examples
Levodopa, pramipexole
Dopamine antagonist drug examples
First-gen antipsychotics (e.g. haloperidol), metoclopramide
Serotonin agonist drug examples
Triptans (e.g. sumatriptan)
Serotonin antagonist drug examples
Ondansetron, second-gen antipsychotics (e.g. quetiapine)
Acetylcholinesterase inhibitor drug examples and action
Donepezil, rivastigmine, galantamine
Blocks acetylcholinesterase, resulting in increased ACh levels // used to treat Alzheimer’s disease
Catechol-O-methyltransferase (COMT) inhibitor drug examples and action
Entacapone
Blocks COMT enzyme to prevent peripheral breakdown of levodopa, resulting in increased duration of action of levodopa; used to treat Parkinson disease
Angiotensin-coverting enzyme (ACE) inhibitor drug examples and action
ACEi (e.g. lisinopril, ramipril)
Inhibits production of angiotensin II, resulting in decrease vasoconstriction and aldosterone secretion; used to treat HTN, HF, and kidney disease
Cyclooxygenase (COX) inhibitor drug examples and action
NSAIDs (e.g. aspirin, ibuprofen)
Blocks COX enzymes to decrease prostaglandins and thromboxane A2; used to treat pain/inflammation and decrease platelet activation/aggregation (Aspirin)
Monoamine oxidase (MAO) inhibitor drug examples and action
MAOi (e.g. phenelzine, tranylcypromine, isocarboxazid, selegiline, rasagiline, methylene blue, linezolid)
Blocks MAO which increase catecholamine levels; used to treat depression
If catecholamine levels increase too much (d/t additive effects with other drugs or food), toxic effect can occur like hypertensive crisis or serotonin syndrome
Phosphodiesterase (PDE) inhibitor drug examples and action
PDE-5i (e.g. sildenafil, tadalafil)
Competitively bind to the same active site as cGMP on the PDE-5 enzyme, preventing the breakdown of cGMP and prolonging smooth muscle relaxation(e.g. in the arteries of the penis); used to treat ED
Vitamin K epoxide reductase inhibitor drug examples and action
Warfarin
Blocks vit K epoxide reductase enzyme which decreases production of clotting factors II, VII, IX, and X; used to treat or prevent blood clots
Xanthine oxidase inhibitor drug examples and action
Xanthine oxidase inhibitor - allopurinol
Blocks xanthine oxidase enzyme which decreases uric acid production; used to prevent gout attacks
Symptoms of serotonin syndrome
Tremor, akathisia (inability to remain still), clonus (involuntary muscle contractions), hyperthermia, sweating
Symptoms of hypertensive crisis
HTN, tachycardia, agitation, death
What are some drugs/food that can increase risk of hypertensive crisis
bupropion, SNRIs, TCAs, stimulants, levodopa, linezolid, methylene blue, tyramine (From food)
What are some drugs/food that can increase risk of serotonin syndrome
SSRIs, SNRIs, TCAs, mirtazapine, trazodone, triptans, opioids, tramado, buspirone, lithium, dextromethorphan, St. John’s wort
Which drugs have a beta-lactam ring?
penicillins, cephalosporin, carbapenems, monobactam (aztreonam)
