First Pass Miss Exam 2 Flashcards
Why is furosemide good for hypercalcemia? What drug should be used for hypocalcemia?
Blockage of NKCC prevents K+ from making lumen most positive charged, inhibiting calcium reabsorption.
For hypocalcemia, blocking NCC via HCTZ will facilitate reabsorption of calcium
Why is furosemide good in acute renal failure and hyperkalemia?
Increases renal blood flow and hence urine flow, which can flush out K+ (via principle cells) as well as intratubular casts
What is amiloride used for?
Prevention of diuretic induced hypokalemic acidosis
-> also prevents entry of lithium into principal cells (blocks ENaC), limiting aquaporin-2 interference in nephrogenic diabetes inspidus
What is spironolactone used for and why?
- severe CHF -> aldosterone mediates myocardial fibrosis, and spironolactone antagonizes this effect of cardiac remodelling
- Primary and secondary aldosteronism
- Hypertension with loop / thiazide diuretics to reduce K+ loss
- hepatic cirrhosis -> reduces edema
What are the two PCSK9 inhibitors and who uses them? How do they work?
- Alirocumab
- Evolucumab
= EVIL-LAIR
Used as a second line to statins when LDL remains high or statin side effects are high, but very expensive.
Increases the expression of LDL-R on liver by monoclonally binding PCSK9
What drug commonly increases plasma levels of statins and what can be taken instead?
Gemfibrizol, a fibrate to lower triglycerides
Can take fenofibrate instead
What are the statins metabolized via CYP3A4 and what drugs can make this a problem?
Simvastatin, lovastatin, and atorvastatin
Macrolides, azole antifungals, and HIV protease inhibitors may decrease their metabolize and increase risk of myopathy / rhabdomyolysis
What is the high vs low total cholesterol range?
Low / desirable: <200 mg/dL
High: >240 mg/dL
LDL: <100, high>160
HDL: <40, high >60
What is the mechanism of action of niacin?
Binds to and activates GPCR in adipose tissue, decreasing release of free fatty acids from stored triglycerides, reducing need for VLDL packaging by liver, and reduction in LDL.
HDL is increased by improved stability of Apoprotein A1
What is the effect of AT2 on the kidney?
Directly stimulates Na/H exchanger in proximal tubule, enhances aldosterone secretion, and increased GFR while decreasing RBF by constricting the efferent arteriole
What is the effect of AT2 on cardiac / vascular remodelling?
Stimulates the migration, proliferation, and hypertrophy of vascular smooth muscle cells, as well as hypertrophy of cardiac myocytes. Promotes myocardial fibrosis through aldosterone.
Also increases preload (volume expansion) and afterload (greater peripheral resistance)
Why are ACE inhibitors important in chronic heart failure? What effect does this have on cardiac output and stroke volume?
Reduce preload and afterload, thus slowing the progress of ventricular dilation
This actually increases cardiac output and stroke volume in CHF
Give two important side effects of ACE inhibitors?
- Persistant dry cough
- Hyperkalemia (due to decreased aldosterone secretion) -> especially a problem in renal failure or if patient is on another K+ sparing diuretic -> raised banana dacquiri
When are ACE inhibitors contraindicated?
Pregnant patients -> teratogenic
Give two angiotensin receptor (AT1) blockers: ARBs?
- Losartan
2. Valsartan
What is the neprilysin inhibitor and how does this work? Who is it used in?
Sacubitril
-> think of it inserting a cube into the neprilysin rather than a stick
Inhibits neprilysin, which is responsible for cleavage of natriuretic peptides which have good effects.
Used in combination with valsartan for treatment of heart failure
How do beta blockers reduce oxygen consumption by the heart?
They reduce the heart rate, allowing for increased filling time and stroke volume
Furthermore, they reduce the inotropy of the heart, resulting in less forceful contractions
What are the dihydropyridines of significance?
- Nefedipine - avoid in MI due to reflex tachycardia
- Amlodipine - longer halflife, no reflex tachycardia
-> reduces mortality in LV dysfunction
think the ‘dipin’ station for ice cream in sketchy
What are the non-dihydropyridine calcium channel blockers?
- Verapamil - Also has alpha 1 antagonist activity -> hypotension. It should not be used in heart failure but decreases digoxin’s clearance.
- Diltiazem
-> very vanilla and delicious dark chocolate ice cream
What is the mechanism of action of the non-dihydropyridine VGCC blockers?
They bind to the L type Calcium channel, but are cardioselective and will bind to both the open and inactivated form.
They reduce inward calcium current and delay channel closing, reducing the chronotropy and inotropy of the heart. -> contraindicated in AV block or with beta blockers due to excessive bradycardia
There is only minor blockage of L-type calcium channel on arteries
What are non-dihydropyridines used to treat and why?
Angina -> reduce cardiac work by reduction of inotropism
Supraventricular tachycardias -> delayed AV node conduction
Antiarrhythmia in general -> DO NOT USE IN HEART FAILURE DUE TO DECREASED INOTROPY
What drugs decrease cardiac remodeling?
Beta blockers (especially carvediol), ACE inhibitors / ARBs (through lack of aldosterone), spironolactone
What is the I-funny channel blocker and how does it work?
Ivabradine -> main use is reduction in tachycardia in people already on beta blockers
Blocks the channel in pacemaker cells, especially the SA node which is activated by hyperpolarization, and leads the pacemaker cells to spontaneously depolarize and allow calcium inside
If channel is a nonspecific channel (lets Na+ and K+ flow)
What is the mechanism of action of dihydropyridines?
They bind the L type Calcium channel in its open state, slowing calcium entry when it’s open, but not delaying its closure.
Dihydropyridines are vasoselective (rather than cardioselective), and prevent vascular smooth muscle contraction -> do not affect preload due to only arterial action
What is the mechanism of hydralizine and why is it not commonly given anymore? When is it given?
Mechanism unknown, relaxes arteriolar smooth muscle to reduce preload.
Not commonly given due to lupus-like syndrome.
Now given to patients who cannot handle standard therapy for heart failure (ACE + beta blocker + loop diuretic) in combination with a nitrate to reduce both preload and afterload
What is the mechanism of action of minoxidil? How does this relate to its contraindication?
Activates ATP-modulated potassium channel in smooth muscle, causing hyperpolarization and arteriolar relaxation
Contraindicated in patients with LV hypertrophy and diastolic dysfunction, as increased preload may lead to heart failure + pulmonary hypertension
What is the mechanism of action of sodium nitroprusside? What does it do to heart rate?
Generates nitric oxide, causing both venous and arterial relaxation, and a subsequent decrease in preload and afterload
Actually causes increase in heart rate (reflex)
What is nitroprusside used for?
Treatment of hypertensive emergencies such as acute aortic dissection (along with beta-blocker to reduce heart rate) or cardiogenic shock due to massive MI or rupture of papillary muscle
What is the mechanism of action of minoxidil? How does this relate to its contraindication?
Activates ATP-modulated potassium channel in smooth muscle, causing hyperpolarization and arteriolar relaxation -> increased preload, decreased afterload
Contraindicated in patients with LV hypertrophy and diastolic dysfunction, as increased preload may lead to heart failure + pulmonary hypertension
-> give with a loop diuretic and beta blocker
Why are beta-blockers always given with direct arterial vasodilators?
Otherwise, will cause reflex tachycardia and increase in renin secretion (beta1-antagonism will counter this)
-> minoxidil, sodium nitroprusside, hydralazine
What is ultralente insulin?
Very slow absorption - also suspended with zinc (like Lente insulin)
What two insulins are very rapidly acting and what is their mechanism?
Lispro insulin and aspart insulin
They are insulin with mutations introduced so insulin does not associate into its hexameric form
“Girls And Lads, Rest Now, Don’t Go”
Glulisine Aspart Lispro, Regular NPH, Detimir Glargine
What are the symptoms of a hypoglycemic state and what can induce it?
Sweating, tremor, blurred vision, and mental confusion
Exercise and stress can also precipitate this (exercise increases glucose uptake by cells)
What are the cutoff’s for diabetes and typical treatment goal of HbA1c?
> 6.5% = diabetes
Goal: Reduce to <7%
What are the adverse reactions of sulfonylureas?
- Induction of severe hypoglycemia
- Stimulation of appetite (due to hypoglycemia) -> weight gain
- High failure rate as disease progresses (beta cell failure)
What are the adverse effects of metformin use and who is it contraindicated in?
GI disturbances -> dose-related, especially at start of therapy - think of the girl puking at the guy professing his love
Lactic acidosis (from decreased usage of lactate in gluconeogenesis)
- > avoid in renal disease, liver disease, or alcoholics
- > think of the broken kidney plate with spilled milk on it
What are the thiazolidinediones (TZDs) also called? What drugs are in this class?
Glitazones
Includes:
- Rosiglitazone
- Pioglitazone
Think girl with glitter - Roses are red -> rosiglitazone
Pioglitazone just think of that dude eating too much pie to get fat
What are the meglitinides?
Repaglinide
Nateglinide
Think of my boy Nate Representing! And the gliding goose for glinides!
What are the adverse effects of glitazones? How does this relate to their usage
This keeps them from being used alot, only used as second line in combination:
- Hepatotoxicity
- Congestive heart failure from 3. Edema - > think of the dude eating pie / donuts with baggy pants and the crushed heart
- Weight gain -> significant -> that dude was fat
- Heart attack
- Bone loss -> bone breaking chairleg
What are the three sulfonylureas primarily being used today?
- Glimepiride
- Glipizide
- Glyburide
Think of the two ducks “riding” mother goose, and a smaller goose making a “z” in the ice for glipiZide
What drug is a GLP-1 homolog isolated from Gila monster?
Exenatide - resistant to DPP-4 protease
Liraglutide - other homolog with resistance to DPP-4 due to one amino acid change
Think of the -tide detergent used to wash the four clothes
What are the actions of exenatide and liraglutide?
Induces insulin release, depresses glucagon release -> good for post-prandial surge
Also: Blunts appetite by delaying gastric emptying
- > associated with significant weight loss!
- > liraglutide even approved for obesity
What are exenatide / liraglutide given with? Adverse effect?
Approved for combination use with sulfonylureas and metformin, may cause nausea
Also may induce hypoglycemia if given in combination with sulfonylureas
What drug is a DPP-4 inhibitor, and what is its primary benefit over the GLP-1 homologs? What is its main side effect?
Sitagliptin (Januvia) -> think of someone sitting down washing those clothes that have been cliptin’ to the clotheslines
Can be taken orally, does not show GI disturbances.
However, no associated weight loss :/
Side effect: Acute pancreatitis
What are the SGLT2 inhibitors?
Dapagliflozin
Canagliflozin
Drugs ending in -gliflozin -> think of the guy flossing in the corner of the classroom and he “CAN look pretty DAPper”
What is the mechanism of action of the TZDs and what drug are they similar to?
Similar to metformin, in that they reduce insulin resistance without posing hypoglycemia risk
Mechanism: activate PPARy receptor, expressed in white adipocytes which is a nuclear transcription factor. This suppresses the release of resistin from white adipocytes
What are the clinical uses / benefits of SGLT2 inhibitors?
Taken orally, modest HbA1c reduction in combination with metformin.
Also reduces CVD outcomes and may promote weight loss due to excretion of glucose
What are the two thyroid replacement therapies and which one is typically used?
- Levothyroxine - T4
- Liothyronine sodium - T3
T4 is used because it is cheaper and has a long half-life for easy treatment.
T3 is only used to treat acute symptoms