Quiz 1 Drugs Flashcards

(78 cards)

1
Q

Mechanism of Atorvastatin

A

Competitive inhibitor for active site on HMG CoA reductase (rate limiting step of cholest. synth); [structural analogs of HMG CoA intermediate] -> decr plasma cholesterol by INCREASING gene expression of LDL RECEPTOR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Indications of Atorvastatin

A

First line use for hypercholesterolemia when at risk for MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Side Effects of Atorvastatin

A

Elevated serum levels of hepatic enzymes; hepatitis; and myalgia, rhabdomyolysis, and other myopathies (muscle pain, weakness). Teratogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pharmakokinetics of Atorvastatin

A

Extensive 1st pass eff (liver) -> limits syst bioavail, targets liver (site of action); high plasma prot binding; half-life: 20 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Contraindications of Atorvastatin

A

Metabolized by CYP3A4; incr risk myopathy w/ erythromycin, gemfibrozil, or naicin; those hypersensit, active liver dis, & pregnant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

First line use for hypercholesterolemia when at risk for MI

A

Atorvastatin, Lorvastatin, Simvastatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Statins have greater effect on LDL or HDL?

Lorvastatin, Atorvastatin, Simvistatin

A

Greater effect on LDL; higher the baseline TG level = greater lowering effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mech of Lorvastatin

A

Competitive inhibitor for active site on HMG CoA reductase (rate limiting step of cholest. synth);> decr plasma cholesterol by INCREASING gene expression of LDL RECEPTOR
**prodrugs, administered as lactones (transformed in liver to active form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Difference in mechanism of Lorvastatin and Atorvastatin

A

Lorvastatin is a PROdrug and activated in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Toxicity of Lorvastatin:

A

All Statins same: Elevated serum levels of hepatic enzymes; hepatitis; and myalgia, rhabdomyolysis, and other myopathies (muscle pain, weakness). Teratogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

PharmK of Lorvastatin

A

Extensive 1st pass eff (liver) -> limits syst bioavail, targets liver (site of action); high plasma prot binding; half-life: 1-4 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Contraindications of All Statins

A

Metabolized by CYP3A4; incr risk myopathy w/ erythromycin, gemfibrozil, or naicin; those hypersensit, active liver dis, & pregnant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Simvastatin and Lorvastatin are the same except:

A

Simvustatin half life = 1-2 hours

Lorvastatin = 1-4 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the HMG CoA Reductase Inhibitors

Statins?

A

Atorvastatin
Lovastatin
Simvastatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Rate limiting step in cholesterol biosynthesis

A

HMG CoA reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do statins prevent substrate binding?

A

• statins inhibit HMGR by binding to the active site of
the enzyme, thus stericallypreventing substrate from
binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How are statins similar and different from HMGR

A

• statins inhibit HMGR by binding to the active site of
the enzyme, thus sterically preventing substrate from
binding
All differ from HMG-CoA by being more bulky and more hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

DOMINANT MECHANISM FOR

CONTROLLING LDL PLASMA CONCENTRATIONS

A

REGULATION OF HEPATIC LDL RECEPTOR PATHWAY IS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

characteristic Side effect of statins

A

characterized by intense myalgia, first in arms/thighs then in entire body
along with fatigue
serum creatine kinase levels increased 10-fold (rare)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

MYOPATHY RISK FACTORS are greater when taking statins with

A

gemfibrozil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

associated with increased risk of myopathy in

Chinese population

A

Simvastatin plus niacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

are statins safe to take when pregnant?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

first line therapy in patients who are at high risk for MI

due to hypercholesterolemia

A

Statins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What pts should not use statins even though they have elevated cholesterol

A

The exception is patients with homozygous familial hypercholesterolemia, who have very attenuated responses to the usual doses of statins because both alleles of the LDL receptor gene code for dysfunctional LDL receptors; the partial response in these patients is due to a reduction in hepatic VLDL synthesis associated with the inhibition of HMG-CoA reductase–mediated cholesterol synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Cholestyramine is what type of medication?
Bile Acid-Binding Resins
26
What is the only way cholesterol is excreated from body?
amount of bile salts (not reabsorbed) excreted (0.8 g/day) accounts for only mechanism for cholesterol excretion
27
How does cholestryramine increase bile acid excretion in feces
anion-exchange resins that readily exchange chloride ions for bile salts in the small intestine and increase bile acid excretion in the feces
28
What is the rate limiting step of bile acid conversion? What effect does cholesteryamine have on it
7 alpha hydroxylase; the increased excretion of bile acids lowers feedback inhibition thus increase breakdown of hepatic cholesterol
29
Increased catabolism of cholesterol from cholesteryamine will increase activity of?
hepatic HMG CoA reductase
30
How does cholestyramine lower plasma LDL-cholesterol? | Two mechanisms
increasing rate of removal of cholesterol through receptor-mediated catabolism - liver responds to lowering of its cholesterol content by forming more LDL receptors (similar to statins)
31
PharmK of cholestyramine:
- quaternary amine; hygroscopic powder administered as chloride salt and insoluble in water - not absorbed but can interfere with absorption of other agents - time delay before effects seen (1-2 weeks)
32
Key Adverse effects of Cholestyramine
mostly GI, gritty consistancy, modest elevation of plasma TGs
33
``` Lipoprotein Profile after pt has been on cholesteryamine patient with normal TG: patient with TG > 250 mg/dl: LDL-C: HDL-C: ```
TG increase transiently significant further increase in TGs reduced by 12-25%; dose-dependent; larger doses associated with more adverse GI effects increase by 4-5%
34
Uses of Cholesteryamine
management of primary hypercholesterolemia; but NOT if pt has elevated TGs!!!!
35
Mech of Niacin/Nicotinic Acid in adipose
inhibits breakdown of TG by hormone-sensitive lipase--> reduces transport of FFAs to the liver and decreases TG synthesis in liver. (niacin couples to Gi in the GCPR, stimulates Gi path--> inhibition cAMP-->decreases hormone-sensitive lipase activity, TG breakdown and release of free fatty acids)
36
Mech of Niacin in the liver
decreases synthesis of VLDL-TG -inhibits DGAT2 (key in catalyzing final reduction in TG synthesis) thus decreased TG to make VLDL and increases apoB degredation
37
PharmK of Niacin
- Different formulations - immediate release (IR) (quick absorbed-more sides) - long acting release, sustained release (SR) (absorbed slowly, increased risk of hepatotoxicity) - extended release (ER) once per day, less side effects
38
Major side effect of taking Niacin
production of intense cutaneous flush and pruritus Devos 1 to 2 hours after taking drug = poor compliance, disappears with continued use flush dt PGDs (take with aspirin)
39
What pts should not take Niacin?
Pts with diabetes, peptic ulcer, gout or hepatic dysfnx
40
Use of niacin with _____ may cause myopathy
statins
41
Lipoprotein Profile after pt has been on Niacin TGs: LDL-C: HDL-C:
TGs reduced by 35-50% (w/in 4-7 days) LDL-C reduced by 25% (takes 3-5 wks) HLD-C increased by 15-30% ***also can reduce Lp(a) which is independent risk factor for 2-3 fold increase in CAD
42
Clinical Uses of Niacin
hypertriglyceridemias and elevated LDL-cholesterol | ****particularly useful in patients who present with both low HDL and high LDL
43
only lipid-lowering drug that reduced Lp(a) levels (40% reduction)
Niacin
44
Is Niacin a recommended tx for hypercholesterolemia?
second or third choice for hypercholesterolemia because of troublesome side effects
45
inhibits cholesterol transfer from intestinal lumen into | intestinal cell.
Eztimibe
46
Mech of Ezitimibe
binds to NPCL1 and decreases rate of CE incorporation into chylomicrons--decreases flux of cholesterol from intestine--> liver thus reduces cholesterol--> VLDL
47
How does Ezitimibe lower plasma LDL-C
increaess expression of LDL receptors
48
PharmK of Ezitimibe
- oral administration | - rapid glucuronidation to active metabolite
49
Adverse sides of Eztimibe | Contraindications
generally well tolerated | - Bile-acid sequestrants inhibit absorption of ezetimibe, Don't administered together
50
Lipoprotein profile for Ezitimibe LDL: TG: HDL:
reduced by 15-20% reduced by 5% increased 1-2%
51
Clinical uses of Eztitimbe?
monotherapy for treatment of primary hypercholesterolemia in patients resistant to statins
52
Do we prescribe Ezitimibe with Statins? | Pros, Cons?
Statins stop cholesterol biosynthesis Ezetimibe inhibit cholesterol intestinal absorption --see possible benefit with reduction of LDL by 60% BUT increased risk of myopathy
53
Gemfibrozil and Fenofibrate are examples of
Fibric Acids/PPARactivators or agnonists
54
Primary fnx of fibric acids?
Lower TG's
55
Mech of fibric acids
bind to PPARalpha (expressed 1˚ in liver and brown adipose) PPAR bind as heterodimers with retinoid X receptor to specific response elements and alter the transcription rate of target genes
56
What happens as a result of fibric acids binding to PPAR alpha?
more lipolysis and plasma clearance of TG-lipoP --activates LPL and reduces procution of apoCIII, a LPL inhibitor reduces FFA for TG synthesis inhibits denova FA synthesis increases HDL (makes more apoAI and apoAII)
57
How are Gemfibrozil and Fenofibrate simular and different in regards to PharmK
Both oral admin and highly bound to plasma proteins Gemfibrozil 1/2 = 1.1 hrs Fenofibrate = 20 hours and is metabolized to active metabolite
58
Side effects of fibric acids
usually well tolerated with GI disturbances | increased gall stones, possible blood/liver fnx abnormalities
59
What pts shouldn't use fibric acids
ones with renal failure
60
When using gemfibrozil + statin we increase....
creatine kinase--- leads to renal failure
61
Typical Lipoprotein Profile after use of fibric acids TG: LDL: HDL:
TG: decrease by 30-50% LDL: decrease by 15-20% highly variable HDL: increase by 5-15%
62
What does the lipoprotein profile for patient using fibric acids depend on?
highly dependent on starting lipoprotein profile, presence or absence of a genetic hyperlipoproteinemia
63
approved for treatment in individuals with very high serum | triglycerides greater than 750 mg/dl
Use Fibric Acids
64
When is it appropriate to use Fibric Acids to tx hypercholesterima
Only when patient has hypertriglyceridemia as well
65
treatment of hypertriglyceridemia (Fredrickson types IV and V)
Fibric Acids
66
recommended for patients 11 to 20 years of age | - most often used as second agents if statins do not lower LDL
cholestyramine
67
approved for use as monotherapy or in combination statins or fibrates for the treatment of hypercholesterolemia.
Ezetimibe
68
hypertriglyceridemia AND elevated LDL - side effects limit its use - useful in patients with both hypertriglyceridemia and low HDL
Niacin
69
Drugs of choice for hypertriglyceridemia
1. Fibric Acids 2. Niacin 3. Omega 3s
70
When do we recommend omega 3 fish oil?
Adjunct to diet therapy in the treatment of hypertriglyceridemia
71
Adverse effect of omega 3s?
fish allergies, may increase LDL, may increase liver enZ, prolonged bleeding.
72
a mediator of hepatic LDL receptor degradation
(PCSK9) Inhibitors
73
Role of PCSK9 in LDLR regulation
hepatic LDLR controlled via STEB-2 and PCSK9: PCSK9 binds LDLRs--> get internalized and directs Rs for destruction--> so DECREASE LDLRs at cell surface ***PCSK9 antibody stops PCKS9 bindng to LDLR-LDL complex = increased LDLRs on cell surface
74
Individuals with GOF mutations in PCSK9 seen in families with FH... what do the mutations cause?
increase the affinity of PCSK9 for LDLR, result in high cholesterol levels and a significantly increased incidence of coronary heart disease
75
How is LOF mutation of PCSK9 a good thing?
prevent interaction with LDLR...LDL-C levels reduced by up to 40% and the risk of coronary heart disease is reduced by up to 88%
76
Adverse effects of PCKS9 inhibitors
IG well tolerated... injection site rxns
77
Uses of PCKS9 inhibitors
for men and women with hypercholesterolemia
78
Mech of MTP (Microsomal triglyceride transfer protein) inhibitors?
MTP plays an important role in the hepatic assembly | of plasma lipoproteins by mediating the transfer of triglycerides to VLDL