Pharmacology Flashcards
1
Q
Michaelis Menten kinetics
- Km
- Vmax
- curve
A
- related to affinity of enzyme for substrate; on x axis
- directly proportional to enzyme concentration; on y axis
- hyperbolic, sigmoid
2
Q
Lineweaver-burk plot
- vmax
- Km
- competitive inhibitors
- noncompetitive inhibitors
A
- y intercept, higher the intercept lower the vmax
- x intercept, further to the right the greater the Km and lower the affinity
- cross each other, and increased Km
- do not cross each other
3
Q
Pharmacodynamics
- competitive inhibitor, reversible: resemble substrate, overcome by [s], bind active site, effect on vmax, effect on Km, pharmacodynamics
- competitive inhibitors, irreversible: resemble substrate, overcome by [s], bind active site, effect on vmax, effect on Km, pharmacodynamics
- noncompetitive inhibitors: resemble substrate, overcome by [s], bind active site, effect on vmax, effect on Km, pharmacodynamics
A
- resemble substrate, overcome by increase in [substrate], bind active site, do not change vmax, increase Km, decrease potency
- resemble substrate, not overcomed by [substrate], bind active site, decrease vmax, Km unchanged, decreased efficacy of pharmacodynamics
- do not resemble substrate, not overcome by [substrate], do not bind active site, decrease Vmax, do not change Km, decrease efficacy
4
Q
Pharmacokinetics
- bioavailability
- volume of distribution
- clearance
- half life
- dosage calculation
A
- fraction of administered drug reaching systemic circulation
- volume of total amount of drug in body relative to plasma concentration
- volume of plasma cleared of drug per unit time; rate of elimination of drug // plasma drug concentration
- the time required to change the amount of drug in body by 1/2 during elimination, 1-50, 2-25, 3-12.5, 4-6.25
5
Q
Types of drug interactions
- additive
- permissive
- synergistic
- tachyohylactic
A
- effect of substance A and B together is equal to sum of individual effects
- presence of substance A is required for full effect of substance B
- effect of substance A and B together is greater that the sum of their individual
- acute decrease in response to drug after initial/repeated administration
6
Q
Elimination of drugs
- zero order
- first order
A
- rate of elimination is constant
- rate of elimination is proportional to drug concentration
7
Q
Urine pH and drug elimination
- what happens
A
- ionized species are trapped in urine and cleared while neutral forms can be reabsorbed
8
Q
Drug metabolism
- phase I
- phase II
A
- reduction, oxidation hydrolysis w/ cytochrome p450
- conjugation, usually yields very polar inactive metabolites
9
Q
Efficacy vs potency
- efficacy
- potency
A
- max effect drug can produce, represented by increase in vmax
- amount of drug needed for given effect, represented by middle of x
10
Q
Therapeutic index
- what is it
- equation
- therapeutic window
A
- measurement of drug safety; high is safe and low needs to be monitored
- median toxic dose // median effective dose
- dosage range that can safely and effectively treat disease
11
Q
Autonomic receptors
- parasympathetic
- sympathetic
A
- Ach on nicotinic, and Ach on muscarinic
- Ach on nicotinic, and Epi on alpha/beta
12
Q
Acetylcholine receptors
- nicotinic MOA
- nicotinic subtypes
- muscarinic MOA
- muscarinic location
A
- ligand gated Na/K channels
- Nn found in autonomics and Nm found in NMJ
- gPCR -> act through second messengers
- muscle , brain, exocrine gland, sweat gland
13
Q
G-protein linked second messengers sympathetic
- alpha 1
- alpha 2
- beta 1
- beta 2
- beta 3
A
- q; increase vascular SM contractions, increase pupillary dilator contraction, increase intestinal and bladder sphincter contraction
- i; decrease sympathetic outflow (epi will bind back on pre-synaptic nerve to modulate release of epi), decrease insulin release, decrease lipolysis, increase platelet aggregation, decrease AQH production
- s; increase heart rate, contractility, renin release, lipolysis
- s; vasodilation, bronchodilation, increase lipolysis, increase insulin release, increase AQH production
- s; increase lipolysis, thermogenesis and bladder relaxation
14
Q
G-protein linked second messengers parasympathetic
- M1
- M2
- M3
A
- q; mediates higher cog functions and stimulates enteric nervous system
- i; decrease heart rate and contractility of atria
- q; increase exocrine gland secretions, increase gut peristalsis, increase bladder contraction, bronchoconstriction
15
Q
G-protein linked second messengers dopamine
- D1
- D2
A
- s; relaxes renal vascular SM, activated direct pathway of striation
- i; modulates transmitter release, especially in brain
16
Q
G-protein linked second messengers histamine
- H1
- H2
A
- q; increase nasal and bronchial mucus, vascular permiability, bronchoconstriction, pruritis, pain
- s; increase gastric secretion
17
Q
G-protein linked second messengers vasopressin
- V1
- V2
A
- q; increase vascular SM contractions
- s; increase H2O permeability and reabsorbtion via upregulating aq-2 in CT
18
Q
Amphetamines MOA
A
- use NE transporter on presynaptic cleft to get into pre-synaptic neuron, then use vesicular monoamine transporter to enter neurosecretory vesicles and displace NE, when NE builds up in the pre-synaptic neuron `the NE transporter that normally reuptakes NE from post synaptic cleft starts releasing it
19
Q
Direct cholinergic agonists
- bethanechol: action, indication
- Cabarchol
- methacholine
- pilocarpine
A
- activates bladder smooth muscle
- carbon copy of Ach but resistant to AchE; constricts pupils and relieves intraocular pressure
- stimulates muscarinic receptors in airway when inhaled; challenge test for asthma
- contracts ciliary muscles of eye, pupillary sphincter, can cross BBB; potent stimulator of sweat, tears, and saliva, open and closed angle glaucoma
20
Q
Indirect cholinergic agonists
- donepezil
- edrophonium
- neostigmine
- physostigmine
- pyridostigmine
A
- increase Ach, 1st line for alzheimers
- increase Ach, used to test for Myasthenia Gravis
- increase Ach, post-op and neuro ileus and urinary retention, reversal of NMJ blockade
- increase Ach, antidote to anticholinergic tox
- increase Ach and muscle strength; tx for myasthenia gravis
21
Q
Acetylcholinesterase poisoning
- caused by
- muscarinic effects: sxs, reversal
- nicotinic effects: sxs, reversal
- CNS effects
A
- organophosphates (insecticides) that irreversibly inhibit AchE; seen in farmers
- diarrhea, urination, miosis, bronchospasm, bradycardia, emesis, lacrimation, sweating, salivation; atropine
- NM blockade; reversed by pralidoximine
- resp depression, lethargy, seizure, coma
22
Q
Muscarinic antagonists
- atropine
- benztrpoine
- glycopyrrolate
- hyoscyamine
- ipatropium
- oxybutynin
- scopolamine
A
- eye; produce mydriasis and cycloplegia
- CNS; parkinson dx
- GI/ resp; preoperative to reduce airway secretions
- GI; anti-spasmodics for IBS
- resp; COPD, asthma
- GU; reduce bladder spasms and urge urinary incontinence
- CNS; motion sickness
23
Q
Atropine effects
- eye
- airway
- stomach
- gut
- bladder
A
- increase pupil dilation
- bronchodilation, decrease secretions
- decrease acid secretion
- decrease motility
- decrease urgency in cystitis
24
Q
Direct sympathomimetics
- albuterol: which receptor, indication
- dobutamine
- dopamine
- epinephrine
- fenoldopam
- isoproterenol
- midodrine
- mirabegron
- nor-epi
- phenyl-epi
A
- binds beta 2 more than beta 1; for acute asthma
- binds beta 1 more than beta 2; heart failure, cardiogenic shock, cardiac stress test
- dopamine 1 and 2; unstable bradycardia, HF, shock
- Beta more than alpa; anaphylaxis, asthma, open angle glaucoma
- D1; post op HTN, hypertensive crisis
- B1 = B2; elctrophysiologic eval of tachyarrythmias
- alpha 1; auto insuff and postural hypotension
- beta 3; urinary urge incontinence or overactive bladder
- alpha 1> 2> Beta 1; hypotension
- alpha 1> 2; hypotension, ocular procedures, rhinitis
25
Q
Indirect sympathomimetics
- amphetamine: MOA
- cocaine
- ephedrine
A
- indirect general agonist, reuptake inhibitor and releases stored catecholamines; narcolepsy, obesity, ADHD
- indirect general agonist, reuptake inhibitor; causes vasoconstriction and local anesthesia
- indirect general agonist, releases stored catecholamines; nasal decongestion, urinary incontinence, hypotension
26
Q
Sympatholytics: indications, side effects
- clonidine
- alpha-methyldopa
- tizanidine
A
- hypertensive urgency, ADHD, tourettes, symptom control for opioid withdrawal; CNS depression, bradycardia, hypotension, resp depression
- hypertension in pregnancy; direct coombs + hemolysis, drug induced lupus
- relief of spasticity; hypotension, weakness
27
Q
Nor-epi vs isoproterenol
- nor epi
- isoproterenol
A
- acts on alpha 1; vasoconstriction, increase mean arterial pressure, reflex bradycardia
- acts on beta; 2- vasodilation, decrease in mean arterial pressure and 1- increase heart rate and reflex activity
28
Q
Alpha blockers non selective
- phenoxybenzamine
- phentolamine
A
- irreversible, pheochromocytoma to prevent catecholamine crisis
- reversible, given to pts on MAO inhibitors who eat tyramine containing foods and for cocaine induced hypertension
29
Q
Alpha blockers a1 selective
- prazosin, terazo, doxazo, tamulo
A
- urinary sxs from BPH
- orthostatic hypotension, dizziness, headache
30
Q
Alpha blockers a2 selective
- mirtazapine
A
- depression
31
Q
Beta blockers
- angina; how does it help
- glaucoma; how does it help, which med
- heart failure; effect
- hypertension; how does it help
- hyperthyroidism; how does it help, med
- HCM
- MI: how does it help
- SVT: how does it help
- variceal bleeding: how does it help, med
A
- decrease HR and contraction resulting in decreased O2 consumption
- decrease production of AQH; timolol
- decrease mortality
- decrease cardiac output, renin secretion
- symptom control, thyroid storm; propranolol
- decreased HR-> increase filling time, relieving obstruction
- decrease O2 demand and mortality
- decrease AV conduction velocity
- decrease hepatic venous pressure gradient and portal HTN; Nadolol
32
Q
Ingested seafood toxins
- histamine: source, action, sxs, tx
- tetrodotoxin
- ciguatoxin
A
- spoiled dark meat fish; bacterial histidine decarboxylase converts histidine to histamine, misdiagnosed as fosh allergy; mimics anaphylaxis, acute burning sensation of mouth, flushing of face; antihistamine, albuterol and epi
- pufferfish; highly potent toxin, binds fast voltage gated Na channels in cardiac and nerve tissues; nausea, diarrhea, paresthesia, weakness, dizziness, loss of reflexes; supportive
- reef fish (barracuda, snapper, moray eel); open Na channels causing depolarization; nausea, vomiting, diarrhea, perioral numbness, reversal of hot and cold sensation; supportive
33
Q
Beers criteria
- what does it do
- meds
A
- developed to reduce potentially inappropriate prescribing and harmful polypharmacy in geriatric population
- alpha blocker, anticholinergics, anti depressants, antihistamine, opioids, benzos, NSAIDs, PPIs
