pharm part1 Flashcards
what is the pKa
pH at which the ionized and unionized concentrations are equal
if pH < pKa, what is favored: the protonated or the unprotonated form
protonated
if pH > pKa, what is favored: the protonated or the unprotonated form
unprotonated
what is the therapeutic index formula
TD50/ED50
bond strength is directly proportional to specificity. true/false?
false. it is indirectly proportional
flux is directly proportional to specificity. true/false?
true
Kd is directly proportional to drug binding
affinity. true/false?
false. it is indirectly proportional
drug safety is directly proportional to drug therapeutic index. true/false?
true
Volume of Distribution (Vd) is directly
proportional to the concentration of drug
outside of the systemic circulation. true/false?
true
what is the definition of volume of distribution
apparent volume of a drug
what is clearance
predicts rate of elimination in relation to drug concentration
in first order elimination, which value is constant
clearance
in zero order elimination, which value is constant
rate of elimination
what 3 meds use zero order elimination
ethanol
phenytoin
aspirin
what 4 parameters affect passive diffusion
molecular weight
pKa
lipid solubility
plasma protein binding
4 basic mechanisms for transmembrane signaling
lipid soluble diffusion to intracellular receptor
ligand binding to RTK
ligand gated ion channel
GPCR
how many trans-membrane alpha helixes does a GPCR have
7
what are the 3 major drug efflux transporters in the ABC family
B, C, G
what is the major site of exclusion in the blood-brain barrier
vascular epithelium
what enzyme is majorly implicated in phase 1 of metabolism
cytochrome P450
if a drug X enhances synthesis of CYP450, and the enzyme deactivates another drug Z, what happens to the effect of drug Z
decreased drug effect
if a drug X enhances synthesis of CYP450, and the enzyme activates another drug Z, what happens to the effect of drug Z
increased drug effect
what is pharmacokinetics
the effects of the body on a drug
what is pharmacodynamics
the effects of the drug on the body
what is pharmacogenomics
the primary reason patients respond differently to the same drug
what is pharmacology
the study of the effects of drugs on the body
what are the 6 neurotransmitter classes
esters - acetylcholine
monoamines - norepinephrine
amino acids- glutamate
purines - adenosine
peptides - substance P
inorganic gases - nitric oxide
where is the location of the ganglia of the sympathetic ANS
close to the spinal cord
where is the location of the ganglia of the parasympathetic ANS
in the visceral effector organs
what enzymes does alpha-1 receptor activate
phospholipase C
what enzymes does beta-1 receptor activate
adenylyl cyclase
what enzymes does beta-2 receptor activate
adenylyl cyclase
the gut has its own nervous system called the
enteric nervous system
alpha1 receptor activation leads to smooth muscle contraction. what are the second messengers produced by agonist binding to alpha-1 receptors
DAG
IP3
give an example of indirect acting adrenergic agonist
amphetamine
give 2 examples of adrenergic antagonist drugs
phentolamine
prazosin
labetalol
what is the important thing to note about phenoxybenzamine (adrenoceptor antagonist drug)
forms irreversible covalent bonds
what effect does beta agonists have on the blood vessels
opposes beta2-mediated vasodilation
which beta blocker is ultra short acting
esmolol
which betablocker is safer in COPD and diabetic patients
metoprolol
atenolol
what is the effect of cholinomimetics on the eye
miosis
increase intraocular drainage
what is the effect of cholinomimetics on the CV
vasodilation
reduction in PVR
bradycardia if given in large doses
what indirect acting cholinomimetic is a simple alcohol
edrophonium
give 2 major uses of indirect acting cholinomimetics
eye disease
GI/Urinary tract
NMJ
atropine overdose
what are the s/s of organophosphate exposure
SLUDGE-M
what are the s/s of poisonous mushroom exposure
SLUDGE-M
what are the s/s of atropine overdose
BRAND
blind, red, absent bowel sounds, nuts, dry
what medication are given for organophosphate exposure
atropine, pralidozime
what medication is given for poisonous mushroom exposure
atropine
what medication is given for atropine overdose
physostigmine
what is the difference between unstable and variant angina
unstable is caused by plaque while variant angina is caused by hyperreactive vessels
what is the action of nitrates on vascular smooth muscle
activate guanyly cyclase and increase cGMP, causing relaxation
what is the action of beta-2 agonists on vascular smooth muscle
act on GPCR to increase cAMP, causing relaxation
what is the action of sildenafil on vascular smooth muscle
blocks PDE-5, increase cGMP, causing relaxation
what are the 3 bad effects of nitrates
orthostatic hypotension
syncope
headache
reflex tachy
what are the 3 good effects of nitrates
reduced preload
reduced heart size
reduced CO
increased venous capacitance
what are 3 effects of calcium channel blocker on the heart
reduced contractility
reduced SA pacemaker rate
reduced AV conduction velocity
dihydropyrides are calcium channel blockers selective for what
peripheral vasculature
verapamil and diltiazem are calcium channel blockers selective for what
cardiac
3 s/s of toxicity of calcium channel blockers
bradycardia
AV block
CHF
what are the 4 antihypertensive agents
diuretics
sympathoplegics
direct vasodilators
anti-angiotensins
what is the hydraulic equation formula
BP = CO X PVR
2 examples of sympathoplegics
clonidine
methyldopa
what is the mechanism of action of clonidine
has alpha agonist activity in the brainstem, decreasing symphathetic stimulation
binds more to alpha-2 than alpha-1
which alpha receptor does clonidine bind more to
alpha-2
what substance produced in the kidney does propanolol prevent from being made
renin
alpha1 blockers such as prazosin reduce blood pressure more in which position (upright or supine?)
upright
what is the mechanism of action of prazosin
blocks alpha1 receptors in arterioles and venules
what is the mechanism of action of minoxidil
opens potassium channels in smooth muscle
name 3 toxicities of hydralazine
headache
nausea
sweating
flushing
what medications are given for hypertensive emergencies
fenoldopam
sodium nitroprusside
what medication inhibits renin from converting angiotensinogen to angiotensin
aliskiren
what medication prevents conversion of kinninogen to bradykinin
kallikrein
difference between systolic and diastolic heart failure
systolic is due to reduced cardiac pumping while diastolic is due to reduced cardiac filling
which heart failure has normal ejection fraction
diastolic
which heart failure does not respond well to positive inotropic drugs
diastolic
what is the mechanism of action of digoxin
inhibits Na/K ATPase
is digoxin a positive or negative inotrope
positive
what dose is the EC50 of digoxin?
1 ng/ml
what dose is the TC50 of digoxin?
2 ng/ml
what is the mechanism of action of PDEi
inactivate cAMP and cGMP
what is the effect of phosphodiesterase inhibitor on cardiac inotropy
they are positive inotropes
what is the normal contraction rate of the SA node
75 beats/min
where is the bundle of His located
interventricular septum
what ions are moving out in phase 1 of the cardiac action potential
K
Cl
what ions are moving in phase 2 of the cardiac action potential and what is their direction of movement
Ca (in)
K (out)
example of type A sodium channel blocker, and what does it do to the action potential duration
quinidine
lengthens APD
example of type B sodium channel blocker, and what does it do to the action potential duration
lidocaine
shortens APD
example of type C sodium channel blocker, and what does it do to the action potential duration
flecainide
no effect
what medication can act as all four classes of the antiarrhytmics
amiodarone
where is the NHE exchanger located
PCT
does furosemide cause acidosis or alkalosis as a side effect
alkalosis
what channel is found in the DCT
NCC
what ion is actively reabsorped in the DCT
Ca
what influence does thiazide diuretic have on carbonic anhydrase
some inhibition
priniciple cells in collecting duct are sites for transport of what ions
water
Na
K
what is the antagonist for ADH in the collecting ducts
conivaptan
effect of toxicity of mannitol
extracellular volume expansion
what are the 4 receptors of histamine
H1
H2
H3
H4
give 2 effects of histamine H1
bronchoconstriction
vasodilation
relationship of antihistamines to H1 (are they: agonist, antagonist, partial agonist, inverse agonist)
inverse agonists
diphenhydramine is most useful for what type of hypersensitivity
type 1
effects of histamine on the nervous system
stimulates pain and itching
effects of first generation H1 antagonist on parkinson disease
suppress extrapyramidal symptoms
effect of first generation H1 antagonist on excitable membrane
act as anesthestic - block Na channel
which substance released in the body during anaphylaxis is slow acting
leukotriene
where is leukotriene liberated during inflammation
lungsw
name 3 effects of leukotriene
bronchospasm
airway edema
mucous secretion
microvascular permeability
what are the 3 bronchodilator classes used to treat asthma
beta agonists
methylxanthines
anti-muscarinics
what are the 3 anti-inflammatory classes used to treat asthma
steroids
antibodies
slow antiinflammatory drugs
what are the 2 leukotriene antagonist classes used to treat asthma
lipooxygenese inhibitors
receptor inhibitors
what is the toxic effect of sympathomimetics
skeletal muscle tremors
what is the clinical use of muscarinic antagonists in asthma
block contraction of airway smooth muscle
what do leukotriene pathway inhibitors do
interrupt synthesis pathway
what enzyme does zileuton inhibit (leukotriene pathway)
5-lipoxygenase
which medication is a leukotriene pathway inhibitor that inhibits binding to receptor
montelukast
zafirlukast
what do anti-IgE monoclonal antibodies do
target the portion of IgE that binds to mast cell
example of anti-IgE monoclonal antibody
omalizumab
