Heart Medchem Flashcards
how is verapamil administered?
orally or IV
which CCB is used as a racemate?
verapamil
DHPs must have what structural feature?
unsubstituted nitrogen on the DHP ring
which substituent at C3 and C5 results in best activity?
Ester (COO-R)
When R3 does not equal R5, the compound is?
chiral
the 4 position of the DHP ring must have?
an aromatic sub (usually Nitrogen)
ortho and meta groups that are ________ ________ increase activity
electron withdrawing
which substitution significantly decreases activity?
para
what are the two metabolic pathways of nifedipine?
condensation rxn and oxidation via Cyp3A4
what can nimodipine specifically treat? why?
subarachnoid hemorrhage
greater lipophilicity = increased distribution to cerebral tissue
what makes nicardipine’s structure unique?
tertiary amine group leading to phenyl ring on C3
what makes nimodipine’s structure unique?
long chain with an ether on C3
what makes amlodipine’s structure unique?
long chain into primary amine on C2
what makes isradipine’s structure unique?
double ring off C4
what makes nisoldipine’s structure unique?
long chain on C3
what is the benefit of isradipine?
less reflex tachycardia
what makes felodipine’s structure unique?
2 chlorines on C4 phenyl ring
what are the requirements of benzothiazepines?
rings should be unsubstituted
aryl group at C2 needs a para sub
ring nitrogen must be alkylated
what are the 3 ways diltiazem is metabolized?
O-demethylation via Cyp2D6
N-demethylation via Cyp3A4
deacetylation
which plant is responsible as the source of digoxin?
digitalis lanata
which plant is responsible as the source of digitoxin?
digitalis purpurea
The digoxin structure is comprised of what structures?
digoxigenin with 3 D-digitoxose attached
why can antibiotics such as erythromycin increase risk of digoxin toxicity?
they kill bacteria in gut which metabolize digoxin which increases its bioavailability making it more potent
how can reducing extracellular potassium (such as furosemide use) increase digoxin potency?
less extracell. K increases phosphorylation which increases binding affinity of digoxin
which drugs increase digoxin’s potency?
which drugs decrease?
quinidine, verapamil, and furosemide
rifampin and bile acid sequestrants
which drug is the only oral inotropic agent?
digoxin
