Weekend 2 lecture 2 Flashcards
Explain Pharmokinetics
What does enternal
parenteral mean?
how is the drug absorbed?”/bioavailability = “how much of the drug is available to be delivered to the target sites.
Drugs enter the body through different routes
Enteral: the drug enters the GI system before it goes into circulation
Parenteral: the drug bypasses the GI system and goes directly into circulation
What is the Bioavability
Decreased distribution as well.
bio-Availability The amount of the drug which is available to the target organ
“first pass effect”
distribution General or restricted depending on the ability of the drug to traverse the cells membranes
What is clearance and what 3 organs are essential for getting rid of the drug.
Describe half life as well.
Clearance - Rate of elimination of the drug by all routes relative to the concentration of the drug in any biologic fluid Mechanisms: Kidney Liver Pulmonary
Half life The time it takes for the the plasma concentration of the drug to be reduced by 50%
The longer the half-life the longer the action of the drug
What are Inotropic drugs?
Drugs used to increase the force of ventricular contraction when myocardial systolic function is impaired.
Thought to work by increasing the intracellular calcium concentration
Digitalis and Cardiac Glycosides what are the desired effects of these medications
Desired effects
Improve contractility of the failing heart
Prolong the refractory period of the AV node in patients with supraventricular arrythmias
How long is the half life for digoxin and how does it get excreted
A series of loading doses must be given to raise the drug’s concentration into therapeutic range
Digoxin is excreted through the kidneys and has a half life of 36-40 hours
Other forms of the drug are excreted through the liver (digitoxin) and have a longer half life
Digoxin Toxicity
Easily toxic because the therapeutic level of the drug is close to the toxic level of the drug.
Signs of digoxin toxicity: nausea/vomiting; anorexia; variety of arrythmias
Sympathomimetic Amines Give some examples of this and what do they do ?
Act by binding to the cardiac Beta 1 receptors, increasing the activity of cAMPincreased release of Calcium from the sarcoplasmic reticulum
Examples: Dopamine, Dobutamine, Norepinephrine, Epinephrine, Isoproterenol
Dopamine Dosages and its effects what does a 1-2 dose do what about a
medimum dose (2-10)
high dose (greater than 10)
Low doses (< 2 micrograms/KG/min) Primarily interacts with receptors which increases blood flow to the kidneys and mesenteric beds Medium doses (2-10) Stimulates the Beta 1 receptorsincreased CO High doses (>10) Also stimulates the alpha receptors causing vasoconstriction and elevating systemic resistance
Phosphodiesterase Inhibitors
Inhibit the actions of phosphodiesterase which reduces the breakdown the cAMP and ultimately enhances the calcium entry into the cell and thereby increases the force of contraction
Intravenous B-type natriuretic peptide (BNP) Just type b personality relaxes people
Natrecor (nesiritide): recombinant human B type natriuretic peptide which is produced by the ventricular myocardium.
It binds to the guanylate cyclase receptor of vascular smooth muscle and endothelial cellsincreased intracellular cGMP with resultant smooth muscle cell relaxation
ACE Inhbitors
Angiotensin converting enzyme is inhibited preventing the conversion of angiotensin Iangiotensin II
Decrease arterial pressure
Facilitate natriuresis (ecrerting sodium out of the kidneys)
Toxcitiy or side effects of Ace Inhibitors just think what it does so what could it cause
Not very common Side effects Hypotension Hyperkalemia Renal insufficiency Cough
Sodium Nitroprusside remember that nitro used in extreme cases good way to remember
A potent dialator of both arteries and veins, used to treat hypertensive emergencies and in ICU settings for IV control of BP
Onset of action is 30sec and its peak effect is achieved in 2 minutes
SNP side effects: blurred vision, tinnitus, disorientation, Nausea—these side effects are associated in metabolic toxic effects of excretion of the drug through the liver
Alpha Adrenergic Antagonists give some examples and what they are used for.
Results in vasodialation
Examples: prazosin, terazosin, doxazosin
Principle indication is hypertension
Direct-Acting Vasodialators
Hydralazine Minoxidil Calcium Channel blockers Diltiazem Verapamil
Calcium Channel Blockers
effects and side effects
Negative inotropic effect
Impeded the influx of calcium across the membrane channels in cardiac and smooth muscle cells
Side effects: hypotension, ankle edema
Nitrates main action
side effects at low doses think ankles
side effects at high doses think reflex
Main physiological action is vasodilatation, particularly of the systemic veins
At low doses, there is greater action at the veinsvenodilation and venous pooling which decreases preload
At high doses, nitrates result in widespread arteriolar dilation and may result in reflex tachycardia as a result of systemic hypotension
What is SL tablets or spray used for very serious issues.
What about IV NTG and its side effects
SL tablets or spray is used in acute anginal attacks, peak action occurs within 3 minutes
Long acting nitrates (imdur) used to prevent chest pain in the setting of chronic angina. These meds have a duration of action from 2-14 hours
IV NTG is used by continuous infusion in the management of patients with unstable angina or acute CHF
Side effects:
Hypotension
Reflex tachycardia
Headaches
flushing
Beta blockers uses and side effects very similair to ace inhbitors
May be specific or non-specific
Decrease myocardial oxygen demand by decreasing heart rate, blood pressure, and contractility
Toxicity/Side effects: fatigue, non selective agents can worsen pulmonary conditions, conduction blocks, can precipitate arterial vasospasm in persons with PVD, abrupt withdrawal can precipitate angina or MI, reduces HDL and elevation of triglycerides
Anti-arrythmics
Lidocaine: most commonly used to suppress ventricular arrythmias
Side effects: confusion, dizziness, and seizures
Amiodarone: long half life and many side effects but can be used for atrial and ventricular arrythmias
Side effects: pulmonary toxicity, anorexia, nausea, thryroid function abnormalities, movement disorders—ataxia, tremors, peripheral neuropathy, and proximal muscle weakness
Adeosine is useful for what and what is it half life
Adeosine useful for the termination of supraventricular tachycardia, creates a temporary AV block
Half life is 10seconds
Diuretics purpose and types
Increase renal secretion of sodium and water Types of diuretics Loop diuretics Thiazide diuretics Potassium-sparing diuretics
kidney diagram slide 32 check it out
Loop diruretics do what and when to use “what part of the kidney’ do they work in primarily
Loop diuretics: act principally on the ascending limb of the loop of Henle
Used in the acute management of pulmonary edema and heart failure
Eg. Furosemide duration of action 4-6 hours
Thiazide does what and blocks what part of the kidney
Thiazide diuretics: act at the distal loop of Henle where they block the reabsorption of 3-5% of the filtered sodium
Eg. Chlorothiazide, indapamide
What Does Spironolactone (spiro) do? think like selective
Potassium-sparing diuretics: relatively weak diuretics that antagonize sodium reabsorption
Eg. Spironolactone
Name one major platelet inhibitor and ones used in replace of the main one beneficial for patients with????
Aspirin
Dipyridamole: used for patients who are intolerant of aspirin but is not as effective
Ticlopidine: beneficial for prevention of thrombotic stroke in patients with TIAs or previous CVA
Anticoagulant Drugs name 3 think nascar
Heparin (IV)
Low molecular weight Heparin (IV)
Warfarin (oral)
Surgical Management begins here
Surgical Management begins here
Surgical Management begins here
Surgical Management begins here
Interventional Cardiology
PTCA and Intracoronary Stent placement explain each whats a rotablader used for (rotating bladder what would this do?
PTCA: Percutaneous transluminal Coronary Angioplasty immediate catheterization and balloon angioplasty of the vessel which is stenotic/blocked
Intracoronary stent placement
Mesh wire is pressed into the vessel wall to hold the vessel open
Rotablader
Generally used for calcified plaques
Interventional Cardiology
PTCA and Intracoronary Stent placement explain each whats a rotablader used for (rotating bladder what would this do?
PTCA: Percutaneous transluminal Coronary Angioplasty immediate catheterization and balloon angioplasty of the vessel which is stenotic/blocked
Intracoronary stent placement
Mesh wire is pressed into the vessel wall to hold the vessel open
Rotablader
Generally used for calcified plaques
Valvular Heart Disease
Mitral Regurgitation, Mitral Valve Prolapse, and Aortic Stenosis (meaning that the atrium becomes narrowed no buneo.
Mitral Valve Regurgitation (why does this happen)
Results usually from disruption of the mitral valve annulus, the leaflets, the chordae tendinae or the papillary muscle dysfunction
Primary MR
Any of the above reasons for the MR
Blood move retrograde from the LVLA
Secondary MR what is this
When a diseased state (ie CHF) causes ventricular dilatation with resultant malalignment or dysfunction of the papillary muscles
What is the Mitral (remember left now) Valve prolaspe about
Mid-portion of one or both leaflets “buckle” into the LA during systole
Acute vs Chronic MR
Acute Causes: rupture of chordae tendinae Medical emergency Extremely high fatality Chronic Causes: congential, Marfans syndrome, SLE, MVP, infectious endocarditis
Surgical Procedures 3 types
Mitral valve replacement
Mitral valve repair
Mitral valve annuloplasty(sureg on puts in a ring t around the mitral valve that helps hold up the leaftlets in place.
Surgical after affects think of where the conduction system of the heart is and how close the surgery can be.
Left ventricular failure is often seen following MVR, as the LV is not used to the increased load
Thus afterload reduction is imperative to decrease LV wall tension
Generally this is maintained for 2-3 months until LV remodeling occurs and LV can tolerate increased workload
Arrythmias are fairly common following valvular
surgery as the conductive system lies very
close to the area
Most common type of Valvular heart disease is and what are its symptoms and causes.
Most common type of valvular heart disease
Causes: congenital, endocarditis, Aortic dissection, HTN, Trauma, Rheumatic fever, Marfans syndrome, Anorectic drugs
Signs/Sx
Angina in the absence of CAD
syncope,
CHF
Classification of AS (aortic stenosis)
Mild AS AVA > 1.0 cm2 (aortic vlalve area) Moderate AS AVA 0.7-1.0cm2 Severe AS AVA < 0.7 cm
High Risk Patients for AS
> 70years
History of previous embolism
Atrial fibrillation
More than one prosthetic valve
When to do surgery?
Correction should occur before irreversible LV dysfunction occurs
Generally will observe if moderate AS and asymptomatic and treat medically
If symptomatic, surgery is indicated
If not a surgical candidate, may undergo balloon annuloplasty
Prosthetic Valves
what are the made of
what the pros and cons
Bioprosthesis Porcine (carpentier-edwards) Pro: low risk for thromboembolism Con: degenerates in about 10 years Mechanical St Jude Pro: generally lasts > 20 years Con: requires chronic anticoagulation
