Pharm NBDE II Flashcards
what local anesthetics are esters
procaine, tetracaine, cocaine
where are amides metabolized?
liver
where are esters metabolized?
MAINLY esterase’s in the plasma
which class of drugs has the most consistency in structure?
local anesthetics
they differ only in their immediate chains (ester or amide) that connects the aromatic group to the tertiary amino terminus
what causes methemoglobinemia?
prilocaine and acetominophen at high doses
what does high systemic levels of local anesthetic lead to?
cardiovascular collapse due to DIRECT myocardial depression and hypotensive shock
how do local anesthetics work?
prevent the generation of nerve impulses by interfering with sodium transport into the neuron
what form of LA can penetrate tissue membrane?
non-ionized, free-base form
the duration of lidocaine is increased in the presence of what drug? and why?
propranolol
propranolol is a beta blower, slows heart, slows blood delivery to liver so that lido is not metabolized and remains in systemic circulation for longer also they compete for the same enzyme site
do esters or amides have longer half lives?
amides
what is the most probable cause of a serious severe LA toxic reaction?
excessive blood levels due to intravascular injection
initially high levels of LA lead to what?
depression of inhibitory neurons on the CNS ** aka cns stimulation (which can lead to convulsion) –> higher levels depress inhibitory and excitatory neurons which leads to overall cans depression which can lead to respiratory depression and death
what disease would make the patient most sensitive to epinephrine in LA?
Graves- hyperthyroidism results in high levels of circulating thyroid hormone which causes a hyper metabolic state and increases sympathetic activity which would lead to a hypertensive crisis
what is the only anesthetic that predictably produces vasoconstriction?
cocaine
given the pKa of a drug, if the pH of body tissue is less (more acidic from inflammation), which form of the drug will predominate?
the ionized (charged) form of the drug. This makes it harder for the drug to penetrate the membrane.
what form of LA blocks nerve conduction?
positively charged - LA penetrate as unionized into the neuron and then re-equibrilate back to charged and uncharged inside to block conduction
what are the AHA limits (in mg) of epi in cardiovascular disease vs. regular patients
0.04 mg for cardiovascular disease vs. 0.2 mg in healthy
why is penicillin G injected rather than take orally?
sensitive to acid degradation
which penicillin has the best gram negative spectrum?
ampicillin
hat drugs are cross-reactive with penicillin?
cephalosporin and ampicillin
which penicillin is useful against penicillanse-producing bugs like staph?
dicloxacillin
what Ab is good for pseudomonas infections?
carbenicillin because its extended spectrum
what is given prophylactically for dental procedures to prevent bacterial endocarditis?
2g of amoxicillin - clindamycin if allergies
how do bactericidal agents work?
kill bacteria through inhibiting rapidly growing cell wall synthesis
how do bacteriostatic agents work?
interfere with protein synthesis on bacterial ribosomes - limit growth
how do antifungals work?
bing ergosterol on fungal cell walls to weaken the the wall
how to sulfonamides work?
sulfonamide is a bacteristatic ab that competes with PABA in folic acid synthesis, thus resulting in a folic acid deficiency
what symptoms are associated with penicillins?
dermatitis, stomatitis, bronchoconstriction and cardiovascular collapse
what ab produces upset stomach and pseudomonas colitis
clindamycin
what type of ab is most likely to cause superinfection? least likely?
broad spec most likely and narrow spec least likely
what side effect is associated with the ab chloramphenicol?
aplatic anemia
what side effect is associated with the ab tetracycline?
liver damage/hepatoxocicty and photosensitivity
what side effect is associated with the ab erythromycin?
allergic cholestatic hepatitis
what ab interactions cancel each other out
static/cidal
what alters the rate of renal clearance of penicillin?
probenacid
what reduces the effectiveness of tetracycline?
antacids or dairy products
what type of ab enhances the action of coumarin anticoag and why?
broad spec because they reduce vitamin K sources
what ab decreases the effectiveness of oral contraceptives?
ampicillin (maybe others?) due to suppression of normal GI flora that recycles steroids –> leads to excretion of steroids from the body
what type of ab inhibit the metabolism of drugs like seldane, digoxin?
macrolides like erythromycin
what is the antiviral used for herpes?
acyclovir
what antifungals treat candidasis?
fluconazole or ketoconazole - systemic
what ab achieves higher concentration in the bone than serum?
clindamycin
what ab achieves higher concentration in the gingival fluid than serum?
tetracycline
what side effect is associated with the ab streptomycin?
8th cranial nerve damage, affecting balance and hearing
what side effect is associated with the anti fungal amphotericin B
nephrotoxicity and hypokalemia
what are the 6 different classes of drugs that can act as hypertensive drugs?
diuretics, beta blockers, alpha 1 blockers, centralyl acting adrenergic drugs, neuronal blockers and ACE
what drugs can treat angina?
nitrogylcerin, propranolol, ca channel blockers
what drugs can treat arrhythmias?
lidocaine, phenytoin, quinidine, verapramil, digitalis, propranolol
what does phenytoin do for arrhythmias?
reverses the effect of digitalis
what drugs can treat CHF?
glycosides like digitalis, digoxin and ACE inhibitors
how does quinine work for antiarrythmatic drugs?
increases refractory period of the cardiac muscles
how does lidocaine help antiarrythmatics?
decreases cardiac excitability
how does digitalis help antiarrythmatics?
decrease the a-v conduction
angina arises from what?
insufficient oxygen to meet the demand of the myocardium
how does nitroglycerin help with angina attacks?
increases o2 supply to the heart by a direct vasodilatory action on the smooth mm. in the coronary arteries
how does propranolol help with anginas attacks?
reduces the o2 demand by preventing chronotropic responses to endogenous epi, emotions and exercise
how do calcium channel blockers help angina attacks?
decreaes o2 demands by reducing after load by reducing peripheral resistance via vasodilation
how do ace inhibitors work?
ace inhibitors like lisinopril and catopril block the enzyme which convert angiotensin I to II . Angiotensin II is a potent vasocontrictor
how does methyldopa act as an antihypertensive?
by acting centrally as a false neurotransmitter stimulating alpha receptors to reduce sympathetic outflow resulting in vasodilation
how does clonidine work as a antihypertensive drug?
selective agonist stimualtes alpha 2 receptors in the CNS to reduce sympathetic outflow outflow to peripheral vessels resulting in vasodilation
how does propranolol work as an antihypertensive drug?
nonselective beta blocker that reduces cardiac output and inhibits renin secretion
how does metoprolol work as an antihypertensive drug?
selective B 1 blocke, reduces cardiac output
how do diuretics work as antihypertensive drugs?
decrease absorption of sodium, resulting in fluid loss and blood volume reduction. this decreases the work that the heart has to do
types of diuretics
thiazides (chlorothiazide)
high-ceiling/loop (furosemide)
potassium sparing (spironalactone)
how to cardiac glycosides work?
postive inotropic effect - increase the force of contraction of the heart by inhibiting the sodium, potassium aptase so more calcium can come in the cell
what compensatory changes of CHF does digitalis help?
increased heart size, rate and edema
what side effect is associated with high-ceiling diuretics?
ototoxicity with deafness
what is the mechanism of the analgesic effects of NSAIDS?
inhibits the synthesis of prostglandins
what is the mechanism of the antipyretic effects of NSAIDs?
inhibits P synthesis in the hypothalamic temperature regulation center
what is the mechanism of the bleeding time in NSAIDs?
inhibits synthesis of thromboxane A2 preventing platelet synthesis
what are the therapeutic effects of aspirin?
pain relief, antipyretic effects, anti rheumatic and anti-inflammatory
what are the adverse side effects of aspirin?
occult bleeding from GI tract, tinnitus, nausea and vommiting A/B disturbance or metabolic acidosis, decreased tubular reabsorption or uric acid, delirium and hypeventillation
what are the differences in acetimenophen and aspirin?
no anti-inflamm, hepatoxocity and does not cause GI upsetness
what is the difference in anti-infamy (like prednisone) and aspirin
since prednisone is a steroid they do not act by PG inhibition
what is the difference in aspirin and ibuprofen?
ibuprofen does not irritate GI
which drug should be avoided in feverish children? why?
aspirin due to reyes syndrome
tylenol is the drug of choice
where is the temperature regulation center?
hypothalamus
which analgesic has the longest half life?
diflunisal
which drug is a mixed agonist-antagonist?
pentazocine and nalbuphine
what is used to treat a morphine OD?
naloxone
what is used to detox morphine addicts?
methadone
side effects of morphine
respiratory depression, euphoria, sedation, dysphoria, analgesia, constipation and urinary retention
an overdose of opiates causes what
coma, miosis and respiratory depression
what is opiates mechanism of respiratory depression?
loss of sensitivity to the medullary respiratory center to CO2
what is demerol?
merperidine, and opiate (analgesiac)
what surpasses the cough reflex best?
opiods - codeine
how does atropine induce tachycardia?
blocks vagal reflex control of heart rate
what are the 3 competitive muscarinic receptor blockers that can be used to control saliva?
atropine, scopolamine and proantheline
what are antichlinesterase drugs?
physostigmine and neostigmine
which anti cholinesterase acts only on the periphery?
neostigmine
what drugs are direct acting cholinergic agonists?
pilocarpine, methacholine
what do organophosphates and insecticides do?
irreversibly inhibit cholinesterase - potentiate cholinergic effect
what is used in organophosphate toxicity?
parlidoxime - enzyme regenerator
what is succinylcholine used to prevent?
laryngospasms
what does succinylcholine do? how does it work?
depolarizing neuromuscular junction blocker
what is d-turbocurarine?
a non-depolarizing neuromuscular junction blocker
what are mecamylamine and hexamethonium?
ganglionic blockers that produce orthostatic hypotension
cholinergic stimulation effects
SLUD
salivation, lacrimation, urination, defecation
plus reduction in intraocular pressure, miosis, bronchoconstriciton, bradycardia, muscle weakness
what type of anticholinergics have CNS effects and what are they
tertiary amines (like atropine)
restlessness, headache, excitement, hallucinations and delirium
how do alpha and beta blockers like prazosin and propranolol work?
by competitive inhibition of adrenergic receptors
how does reserpine work?
depletes NE by inhibiting re-uptake
how does guantheidine work?
inhibits release of catecholaines
how do amphetamine, tyramine and ephedrine work?
adrenergic drugs that work indirectly by stimulating the release of stored NE
How do MAOI work?
block enzymatic degradation of adrenergic
what is epinephrine reversal?
in the presence of an alpha blocker like parson (or chlorpromazine) epi will cause a decrease in BP rather than an increase because beta mediated vasodilation will predominate
what is vagal reflex?
administering a pressor dose of NE may result in a decrease of HR due to activation of baroreceptors that stimulate vagal reflex to reduce heart rate
what medication is given to parkinsons patients?
carbidopa and levadopa (carbidopa blocks decarboxylase activity in the periphery to allow the levodopa to pass through BBB)
how to measure therapeutic index
lethal dose/effective dose
higher index, safer the drug
what is the mechanism of action of benzos?
modulate the activity of the neurotransmitter GABA
what are the advantages of benz over barb?
less addiction potential, less profound CNS depression, larger therapeutic index, less respiratory depression
what can diazepam cause with IV injection?
irritation like thrombophlebitis due to the glycol propelene that dissolves the fluid
are barbitutes analgesics?
NO - they actually might worsen the pain
how is thiopental (a barbiturate) terminated?
rapid redistribution from the brain
how would a barb overdose kill you?
resp depression
what condition are barbs contraindicated in?
patients with porphyria - they enhance porphyria synthesis and aggravate the disease
why are barbs problematic as anesthetics?
induce salivation and bronchial secretion - thus give an anticholinergic before
example of anti psych drug
phenothiazines like chlorpromazine
what is the mechanism of action of anti psych drugs
block dopamine
what are the major side effects of anti psych drugs?
anticholinergic and extrapyramidal - results in tradeoff dyskinesia
what is clozapine?
2nd generation anti psych
blocks dopamine and serotonin receptors
*no tardidive dysplasia
what are the most commonly used antidepressant med?
TCA
what is the drug of choice for a manic depressive?
lithium
what influences the rate of induction of GA?
solubility
more soluble, more drub needs to be given to reach critical tension in the brain
onset of GA is inversely proportional to solubility of anesthetic in the blood
what GA is associated with hepatotoxicity?
halothane
what are the stages of GA
1- analgesia
2- delirium
3- surgical anesthesia
4- medullary paralysis
what are antihistamines H1 useful for?
treating derm manifestations of an allergic response
pre-op medication for sedation, antiemetic properties and anticholinergic effects
for controlling parkinson symptoms - cholinergic and dopamine pathways interact in the brain so stopping the cholinergic pathways allows the dopamine to be uninterrupted
what are antihistamine H2 useful for?
reduce gastric acid secretion (OTC heartburn med) - cimetidine
what treats trigemminal neuralgia?
phenytoin and carbamazepine
what is the best anticonvulsant?
diazepam (valium)
what are the enteral routes of admin?
oral, sublingual, rectal
how do you know if a patient is adequately sedated?
verills sign
