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
