Pharmacology Lipid Disorders Flashcards
Niacin mechanism
in adipose, inhibits FFA mobilization (GPR109A)
in liver, decreases VLDL-TG synth
inhibits uptake of HDL-apoA1
(main effect is to decrease TG)
adverse effects gemfibrozil, fenofibrate
increased creatine kinase is coadmin with statin > renal failure
gemfibrozil may block statin transport in liver (icnreased concentrations)
greatest LDL impact
HMG Coa reductase inhibitors
Atorvastatin
Lovastatin
Simvastatin
mechanism omega3 FA
unique TG lowering properties
results in very low density VLDL TG
pharmacokinetics MTP inhibitors
extensive CYP#A4 to inactive metabolites M1 and M3
contraindications to statins
pregnant, lactating, could become pregnant
hypersensitivty
active liver disease
pharmocokinetics cholestyramien
not absorbed
mechanism ezetimibe
acts at NPC1L1 to decrease absorption of cholesteryl ester incorporation into chylomicrons (reduced cholesterol flux from intestine to liver)
Dominant mechanism for controlling LDL plasma concentrations
Regulation of hepaatic LDL receptor pathway
associated polymorphism with statin myopathy
SLCO1B1
(lead to reduced hepatic uptake and increased plasma concentration)
___ and ___ are admined as inactive lactones, which are transformed to active forms in liver
Simvastatin and lovastatin
niacin mechanism - decrease synthesis of VLDL-TG
inhibit DGAT2 that catlayzes final TG synthesis
increases ApoB degradation (major protein of VLDL/LDL)
pharmacokinetics niacin
oral admin, multiple formulations
Greatest HDL impact
Niacin
Ezetimibe lipoprotein pofile
TG decrease by 5%
LDL decrease by 15-20%
HDL increase by 1-2%
only mechanism of cholesterol excretion
conversion to bile salts via 7a Hydroxylase
Statin lipid profile
TG decrease by 20-55%
LDL decrease by 5-10%
HDL increase by 5-10%
adverse effecs cholestyramiune
constipation, bloating
interferes with other drug absorption
modest increase in TG (but normalizes)
gritty consistency
lipoprotein profile gemfibrozil, fenofibrate
TG decrease 30-50%
LDL - decrease 15-20%
HDL - increase 5-15%
Niacin mechanism - inhibit FFA mobilization from adipose
Niacin receptor 1 > decrease in cAMP
> PKA doesn’t phos perilipin and HSL
>TG not broken down into FFA and glycerol
mechanism of action, statins
competitive inhibition of active site on HMG CoA reductase > rate limiting step of cholesterol biosynth
reduction leads to increased numbers of LFL-receptors and thus more uptake
pharmokinetics of statins
(uptake via)
extensive first pass
uptake via OAT1B1
extensive plasma protein binding
other beneficial effects of omega 3
reduced risk for fatal arrhythmias
enhanced plaque stability
reduced HR
improved endothelial function
metabolism of statins primarily via
P450 CYP3A4
specific HTP inhibitor indication
homozygous FH
meechanism PCSK9 inhibitors
blocks PCSK9 targeting of LDR to lysosome for recyling > increase LDLR
primary impact of Fibrates
lover levels of TG rich lipoproteins
mechanism of statin induced myopathy
blockade of HMG CoA reductase also supprsses formation of isoprenoids required for normal muscle function
pharmacokinetics fenofibrate, gemfibrozil
oral
plasma protein binding
fenofibraate metabolized to active
gemfibrozil metabolized to inactive
pharmacokinetics ezetimibe
oral admin
metabolized to active form
half life 22
niacin lipid profile
TG decrease 35-50%
LDL decrease by 25%
HDL - increase by 15-30%
Lpa reduced by 40%
mechanism gemfibrozil, fenofibrate
bind as heterodimers to PPAR-a receptor in liver, adipose > regulates gene transcription, chief among those increase LPL that breaks down TG
lowers levels of TG rich lipoproteins
first choice hyperchholesterolemia drugs
HMG Coa reductase inhibitors
apoB 100 inhibitors adverse effects
injxn site
flu-like
elevation of liver enzyems (rsk hepatotoxicity)
mechanism Cholestyramine
highly postive binds highly negative bile acids > large resins not absorbed and thus excreted
(excretion depletes bile acids, which are synthesized from cholesterol)
(reduced chol > activates SREBP > increase LDL receptor gene transcription
drug of choice for hypertriglyceridemia
Gemfibrozil/fenofibrate
(then niacin, then Omega3)
greatest TG impact
Fenofibrate, Gemfibrozil
Class Atrovastatin
Lovastatin
Simvastatin
HMG CoA reductase inhibitors
MTP inhibitors adverse effects
significant GI
hepatotoxicity
ApoN-100 inhibtion mechanism
antisense oglionucleotide inhibit synthesis of apoB-100 in liver
(apo B binds LDL to receptor, crucial for transport)
adverse effects niacin
intense cutaneous flsuh/pruritis (via PGD2 from macrophages)
.GI effects
hyperuricemia (gout concern)
Increase fasting glucose, insulin resistance
cholestyramine liporotein profile
TG - transient increase (larger if higher baseline)
LDL - decrease by 12-25%
HDL - increase by 4-5%
rarer, serious side effects statins
myositis or liver enzyme elevations
myopathy
rhabdomyolysis
MTP inhibitors mechanism
prevent assembly of apo-B containing lipoproteins in entoerocytes and hepatocytes > reduced chylomicrons and VLDL > reduced plasma LAL-C concetration
(statin use) when cholesterol decreases, ___ and ____ no longer bind, so SREBP-SCAP is transpoted to golgi and cleaved at ___ and ___
this leads to transcriptionally active SREBP > activates target genes
(statin use) when cholesterol decreases, **SCAP **and INSIG no longer bind, so SREBP-SCAP is transpoted to golgi and cleaved at S1P and S2P
this leads to transcriptionally active SREBP > activates target genes