Cardiovascular Drugs Flashcards
What are the components that make up chylomicrons?
Triglycerides (free FAs + glycerol)
Cholesterol
VLDL formation and metabolism
- synthesis of VLDL by liver
- conains triglycerides and cholesterol esters
- assembled in ER
- Hydrolyzed by LPL
- HDL is cleaved off
Uses of LDL
Hormone production
BIle acid production
Cell membrane synthesis
What results from high circulating LDL?
Form foam cells
(accumulate intracellular cholesterol)
Formation of athermatous plaques
Where are HDLs synthesized? What are their components? Why are they beneficial?
Liver and Intestines
phospholipid and apolipoproteins
Benefit: removal of excess cholesterol from cells = anti-atherogenic!
Optimal levels of:
- Cholesterol
- LDL
- HDL
- Triglycerides
- Cholesterol: <200
- LDL: <100
- Goal: <160 unless there are other risk factors
- Risk factors: CHD, diabetes, Vascular disease
- HDL: >60
- Triglycerides: <150
What is metabolic syndrome?
- Abdominal obesity (precipitating factor)
- Atherogenic Dyslipidemia (lipids the wrong way)
- Small LDL, low HDL, High Tg
- HTN
- Insulin Resistance
- Prothrombotic/Proimflammatory state
**All can be fixed by weight loss
Some causes of Secondary Dyslipidemia
- Diabetes
- Hypothyroidism
- Obstructive Liver Disease
- Chronic Renal Failure
- Drugs (progestins, anabolic steroids, corticosteroids)
What are the effects of taking fish oil?
- Increase cell membrane fluidity
- may help prevent hardening of arteries
- Alter receptor responses
- Antiarrythmic
- Decrease Triglycerides
Dose recommendations for Fish Oil
- For Primary Prevention
- For Secondary Prevention (previous CV event)
- For Hypertriglyceridemia
- For Primary Prevention
- 500mg/day
- For Secondary Prevention (previous CV event)
- 1g/d
- For Hypertriglyceridemia
- 4g/d
What is the mechanism of action of statins?
- Competitive inhibitors of HG CoA reductase (rate-limiting step in Cholesterol synthesis
- reduced cholesterol in the liver
- Increased LDL receptor formation and cycling (bring LDL and cholesterol into cell)
Final result:
- Decrease LDLs
- Raise HDLs
- Decrease Triglycerides
- decrease in VLDL synthesis
Change in lipid profile with use of statins
- Decrease:
- Total cholesterol
- LDL
- Triglycerides (TGs)
- Apo-B
- Increase:
- HDL
Side effects of Statins
- Hepatic
- increased aminotransferases
- Myalgia
- May have Increased serum creatine kinase
- could also be related to trauma or hypothyroidism
- May have Increased serum creatine kinase
- Proteinuria
What is the Mechanism of Action of Fibrates?
- decrease cholesterolgenesis, hepatic lipogenesis, secretion of VLDL
- increase LPL activity
- Decrease LDL
- increased oxidation of TG-derived FA
- decrease TGs
What is the mechanism of action of Niacin (Nicotinic Acid)?
- Decreased FFA from adipose to liver
- Decreased VLDL synthesis
- Decreased LDL synthesis
- Increased HDL
What is the mechanism of action of bile acid sequestrants? What side effect is present?
Mechanism of action:
- Bind bile acid in the intestine and prevent reabsorption
- Livers need to produce more (use cholesterol)
- Decreased cholesterol in the body
Side effect: bloating
Neuromuscular blockers
- Function
- Act on what receptor?
Function:
- Paralysis (sequence below)
- mm of fine movement
- limbs
- trunk
- intercostals
- Diaphragm
- No analgesic properties
Receptor: Nicotinic ACh receptor
Excretion mechanisms of non-depolarizing neuromuscular blockers
- Renal (Primary)
- Liver
- Hofmann Elimination
- spontaneous breakdown
- Plasma (plasma esterases)
Recovery can be accelerated by cholinesterase inhibitor
How to accelerate recovery from paralysis with any non-depolarzing neuromuscular blocker
Recovery can be accelerated by cholinesterase inhibitor
Drugs enhancing curare-type Neuromuscular blockade
- Aminoglycoside antibiotics
- Calcium channel blockers
- Inhalation anaesthetics
Succinylcholine
- Type of drug and structure
- What is the initial response to administration?
- Depolarizing neuromuscular blocker (anesthetic muscle relaxant)
- Structure: looks like 2 ACh
- cholinesterases terminate function
- What is the initial response to administration?
- Wave of fasciculation (achy feeling later)
Side effects and contraindications of Succinylcholine (depolarizing neuromucular blockade)
Side effects:
- Myalgia (due to fasciculation)
- Potasium release from skeletal muscle
- hyperkalemia => arrythmias
- Prolonged paralysis (with atypical pseudocholinesterase)
- Malignant hyperthermia
Contraindications
- extensive burns/soft tissue damage
- Paraplegics
- Spinal chord injury
- DMD in children
Treatment of malignant hyperthermia
- ***Dantrolene
- Hyperventilation
- Cooling
What is the mechanism of action of local anesthetics?
Block “fast” voltage-gated sodium channels in nerves to reversibly block conduction
Which nerve types are blocked by local anesthetic?
- Small fibers: A-delta and C fibers
- unmyelinated
- Function: pain, temp, touch
- Bigger ( A-alpha, a-beta, motor) = less sensitive
Autonomic > Pain fibers > Sensory fibers > Motor fibers
Two types of linkage present in local anesthetic molecules
- Ester link
- Amide link
Metabolism of Amide and Ester-type local anesthetics
Amide
- Broken down in liver
- P450 (problem with hepatic disease)
Ester
- hydrolysis
- Not in liver
- Plasma cholinesterases
Drugs within both groups vary in duration
What is the result of the use of epinephrine (a vasoconstrictor) with (after) a local anesthetic?
Vasoconstrictor will
- Decrease absorption/redistribution
- Prolong duration of anesthesia
- Reduce risk of systemic toxicity
What intrinsic qualities of local anesthetics affect their duration of action?
- Protein binding
- Hydrophobicity
- more lipid soluble, more potent
Bupivacaine
- Use
- Primary site of action
- Risk
- Use
- Anesthetic for long-duration surgeries
- Low dose for obstetrics
- Primary site of action
- spinal nerve roots
- Risk
- Cardiotoxicity
Etidocaine
- Use
- Primary site of action
- Use
- muscle relaxant during surgery (motor block)
- Primary site of action
- spinal nerve roots
With spinal anesthesia, a sympathetic block may occur. What are common results of a sympathetic block?
- Vasodilation: results in
- blood pooling
- Reduced CO
- Treatment:
- fluids
- vasoconstrictors
What is the function of Benzocaine?
Topical anesthetic
What is the function of a eutectic mixture of lidocaine and prilocaine?
anesthetic action to 5mm after topical administration
Eutectic = low melting point
What are some side effects of local anestetics?
- CNS
- Simulation
- Depression
- Heart: Depression
- Decreased conduction
- Decreased force of contraction
- Decreased excitability
- Vascular
- Vasodilation => decreased BP
Contraindications of anesthetic amides? Of anesthetic esters?
Amides: hepatic disease
Esters: low esterase activity
What are the components of the anesthetic state?
- Amnesia
- Sedation (decreased arousal)
- Hypnosis (unconsciousnenss)
- Immobility
First anesthesia and date of discovery
Ether, 1842
What is Minimum Alveolar Concentration (MAC)? How is it measured? What are its limitations?
- Concentration of gas in alveoli that results in a lack of pain response in 50% of subjects
- Measure concentration of expired air (at equilibrium)
- Limitations:
- 50% still respond to pain
- may not lose consciousness
***Want to give dose >MAC***
High MAC = less potent, quick time to action
Low MAC = more potent
What is the Mechanism of Action of General Anesthetics?
- increase GABA receptor activity
- increase activity of potassium channels
- Decrease activity of ACh receptors
- Decrease activity of glutamate receptors
What are the function and contraindications Barbiturates?
General anesthetic
Con: Porphyria
Clearance (rapid, but continued infusion helps)
Propofol
- Function
- characteristics:
- analgesia
- clearance
- Function: General anesthetic
- Poor analgesia, poor respiratory depression
- High degree of clearance (rapid recovery)
Etomidate
- Function
- Used in which special population? Why?
- Toxicity effect on adrenals
- Function:
- General anesthetic
- Cardiostable => use in patients at risk of hypotension
- Toxicity
- causes suppression of adrenocortical stress response
Ketamine
- Function
- Side effects
- Use in special populations
- Toxicity effects
- Function
- General IV anesthetic
- Side effects
- increased BP (increased cerebral blood flow)
- Bronchodilator
- Use in special populations
- At risk for Hypotension
- Bronchospasm
- Toxicity effects
- emergence delirium
Cause and Treatment for malignant hyperthermia
- Cause:
- hypermetabolism
- Treatment:
- dantrolene
Clinical problems of IV anesthetics
- Respiratory depression
- low response to CO2 or hypoxia
- CV depression
- Muscular rigidity (Opioids)
Which General anesthetics are used in patients at risk of hypotension?
Etomidate
Ketamine
Which general anesthetic is used in patients at risk for bronchospasm?
Ketamine
Which general anesthetic is associated with emergence delirium?
Ketamine
Which general anesthetic is used to increase cerebral blood flow?
Ketamine
Inhalation anesthetics are what molecule type?
Halogenated hydrocarbons
What is Henry’s Law? What are its implications?
Concentrations of drug in liquid = partial pressure of gas x solubility
The amount of gas which is soluble does not contribute to partial pressure and does not enter other tissues
What is the effect of the blood/gas partition coefficient on induction and duration of anesthetic?
- Partition coefficient measures solubility
- Higher = longer time to induction
- Higher = longer duration of action
What is the blood/gas coefficient of NO? What is it’s potency?
Low coefficient
Not potent (short effect) but quick effect
What is the blood/gas coefficient of Halothane? What is it’s potency?
High coefficient
Potent, but takes time for effect
Halothane
- Blood/gas co-efficient
- Toxicity
- High coefficient: potent but takes time for action
- Toxicity:
- Liver tox: hepatitis and hepatic necrosis
- Malignant hyperthermia
Cause and Treatment of malignant hyperthermia
Cause: hypermetabolism
Treatment: dantrolene
Desflurane
- Important side effect
- MAC
- inhaled anesthetic
- Strong airway irritant
- MAC = 6%
- not soluble
- Faster effect
- Shorter duration (not potent)
Sevoflurane
- MAC
- Inhaled anesthetic
- Not an airway irritant
- MAC = 2%
- more potent than desflurane
NO
- Function
- MAC
- Inhalant anesthetic
- MAC = 105%
- quick induction
- short action
Effect of blood-gas coefficient on induction time
Proportional
- Low = short induction time
- High = long “
Effect of MAC on Potency
Inversely proportional
- Low MAC = Strong potency
- High MAC = Weak potency
Effect of oil-gas coefficient on Potency
Measures lipid solubility
Proportional
- High coefficient = strong potency (high lipid solubility)
- Low coefficient = low potency
What is the mechanism of action of ACE inhibitors?
- inhibit Angiotensin I to AII
- Reduce Na+ and water retention
- Decrease afterload and wall tension
- Inhibit cardiac remodeling
- Inhibit degradation of bradykinin
- Prostaglandin synthesis
- Vasodilation => Decreased BP
- Increase renal blood flow
***Decreased TPR and effective circulating volume***
Where are ACE Inhibitors metabolized? What are the exceptions?
- Kidneys
- Exceptions: Kidneys and liver
- Fosinopril
- Spirapril
What is the effect of ACE inhibitors in patients with elevated plasma renin activity? How is their treatment modified?
- Effect:
- hyper-responsive to induced hypotension
- Initial dose should be reduced
- At-risk patients:
- CHF, Na depletion
What are the therapeutic uses of ACE Inhibitors?
- Hypertension
- especially in diabetic patients b/c are renal protective
- CHF
- counteract ventricular remodeling
- L Ventricular Systolic Dysfunction
- even w/o overt symptoms
- Acute MI
- especially in diabetic and hypertensive patients
- Chronic Renal Failure
- associated with T1DM
- Captopril and Lisinopril
How do ACE Inhibitors counteract hypertension?
- Decreased TPR
- Increase Na+/water excretion at lower BP
- Increased arterial compliance
What drugs are used in Hypertension with Diabetes?
ACE Inhibitors
What drugs are used in MI with either hypertension or diabetics?
ACE Inhibitors
Which drugs are used to delay/prevent Chronic Renal Failure with Diabetes type I?
Captopril
Lisinopril
(ACE Inhibitors)
What is the MOA of renal protective effect in ACE Inhibitors?
- Decrease BP and resistance => Decreased glomerular pressure
- Decreased damage to GBM
What are the adverse effects associated with ACE Inhibitors?
- Teratogen (fetal hypotension)
- Acute renal failure
- In diseases with decreased renal perfusion
- CHF, bilateral renal stenosis, volume depletion (BP dependent on RAAS)
- Cough
- Angioedema
- first-dose effect
- Hypotension
- first-dose effect
- Hyperkalemia
- In patients with renal insufficiency or who are taking drugs that promote K uptake
What is the MOA in ARBs?
- Angiotensin II antagonists
- selective competitive for AT1 receptors
- Decrease TPR
- Decrease effective circulating volume (increase Na+ and H20 excretion)
- Inhibition is insurmountabile
- blockade even with missed dose
What are the therapeutic uses of ARBs?
- High renin forms of hypertension
- Renoprotective in Type II Diabetes
What are the adverse effects of ARBs?
- Teratogen
- Hypotension/Acute Renal Failure
- In patients whose BP is dependent on RAAS
- Hyperkalemia
- In renal disease or taking drugs that promote K+ retention
What are the differences between ACE inhibitors and ARBs?
ARBs:
- reduce activation of AT1 receptors more effectively
- Do not affect Bradykinin levels
- No cough
- No angioedema
ACE Inhibitors:
- Increased levels of Bradykinin
- Cough
- Angioedema
- Increased Ac-SDKP
- Promotes toxic anemia
Both:
- Other side effects are the same
- Affect RAAS
Aliskiren
- MOA
- Indications
- Contraindications
- MOA
- Direct renin inhibitor
- Indications
- Hypertension
- Contraindications
- Diabetes
- Renal Impairment
- Use with ACE inhibitors or ARBs
What is diuretic braking?
- Renal compensatory mechanisms that bring Na+ excretion in balance with intake
- Activate SNS
- Activate RAAS
- Decreased arterial BP (decreased pressure natriuresis)
- Hypertrophy of renal epithelial cells
- **Important in the use of DIURETICS
What is the MOA of Carbonic Anhydrase Inhibitors (CAIs)?
-
Inhibit membrane and cytosolic Carbonic Anhydrase
- excrete carbonic acid, Na+, and Cl-
- Proximal tubule
- Increased phosphate excretion
- Decreased acid reabsorption in collecting duct
- Renal effects
- Increased afferent arteriolar resistance
- Reduced Renal blood flow
- Reduced GFR
- Inhibition of CA in eye
- decreased aqueous humor formation
Location of CAI action in the kidney
Proximal tubule
Indications of CAIs
- Glaucoma
- Due to decreased aqueous humor and intraocular pressure
- Altitude sickness
- Correct metabolic alkalosis
- Increased HCO3- secretion
- Inhibit reuptake of weak organic bases
Adverse effects of CAIs
Sulfonamide derivatives:
- allergic rxn in patients hypersensitive to sulfonamides
- Bone marrow depression
- Renal lesions
- Skin toxicity
- Metabolic / Respiratory Acidosis
- Renal calculi
- Direct renal ammonia into circulation
Contraindications of CAIs
- Hepatic cirrhosis
- directs ammonia into circulation
- Hyperchloremic acidosis
- COPD
- worsens respiratory acidosis
What is the MOA of Osmotic Diuretics?
- Reduce the vertical osmotic gradient in the Loop of Henle
- Results in reduced water reabsorption in the collecting ducts
- Increased excretion of nearly all electrolytes
- Renal:
- Increased RBF (dilate afferent arteriole)
- Total GFR unchanged
What are the therapeutic uses of Osmotic Diuretics?
- Acute Renal Failure
- attenuate decreased GFR
- Reduce cerebral Edema
- Reduce IOP
- Dialysis disequilibrium syndrome
- Hypotension and CNS effects
Contraindications and Adverse effects of Osmotic Diuretics
- Pulmonary edema
- In CHF or pulmonary congestion
- Hyponatremia
- Hypernatremia and dehydration
- con: aneuric patients from severe renal disease
Contraindications;
- Patients with active cranial bleeding
- CHF/Pulmonary congestion
- Aneuric patients with severe renal disease
What is the MOA of Loop Diuretics?
***Inhibit the Na-K-2Cl symporter in the thick ascending limb of the loop of henle***
- Large effect on Na excretion
- 25% normally reabsorbed here
- Reduce vertical medullary osmotic gradient
- Decreased water reabsorption in collecting duct
- Furosemide increases venous capacitance (distensibility)
- reduces pulmonary edema before diuresis begins
What is the elimination half-life of Loop diuretics? How does this affect treatment?
Short elimination half-life
Cannot be used for long-term therapy
What are the therapeutic uses of Loop Diuretics?
Conditions with edema:
- Pulmonary edema (diuresis and increased venous capacitance)
- CHF congestion
- Nephrotic syndrome
- Liver cirrhosis (ascites)
- Hyponatremia (used with hypertonic saline)
What are the adverse effects of Loop diuretics?
- Ototoxicity
- Fats go wrong way (LDL, cholesterol and TG up; HDL down)
- Hyperglycemia
- Hyperuricemia (leads to gout)
What are the contraindications of Loop diuretics?
- Postmenopausal osteopenic women
- Calcium loss
- Hypersensitivity to sulfonamides
What is the mechanism of action of Thiazinde Diuretics?
***Inhibit Na/Cl symport in distal convoluted tubule***
- Increased excretion of K+, Acid, Uric acid (but not with chronic use)
- Decreased excretion of Ca2+, increased reabs. of Ca2+
What are the therapeutic applications of Thiazide diuretics?
- Hypertension (First-line agent)
- Dose for anti-hypertensive effect is lower than for diuretic effect
- Nephrogenic diabetes insipidus (decreased urine volume)
- Calcium nephrolithiasis (stones)
- Osteoporosis
What are the adverse effects of Thiazide Diuretics?
- Hypokalemia
- Hyperglycemia
- Increased lipid profile
- ED
- sulfonamide hypersensitivity
What effect results from combined use of thiazide diuretics and Quinidine?
- Quinidine: prolonged QT
- Thiazide diuretics: hypokalemia
- Result:
- Early after-depolarizations
- Torsades de Pointes
- Ventricular fibrillation
What is the MOA of Amiloride?
***Blocks epithelial Na+ channels in distal tuble and collecting duct***
- Because uptake of sodium usually causes excretion of K+, blockage of this channel is K-sparing
What are the therapeutic applications of Amiloride?
Used in conjuction with more effective diuretics to reduce K+ excretion and prevent hypokalemia
- Edema
- Hypertension