Cardiac Pharmacology Flashcards
1
Q
Lifestyle changes recommendations
A
- Following a healthy diet
- Being physically active
- Maintaining a healthy weight
- Quitting smoking
- Moderating alcohol consumption
- Managing stress
2
Q
Routes of administration
A
- Oral
- Intravenous (IV)
- Intramuscular (IM)
- Subcutaneous (SC)
- Sublingual
- Rectal
3
Q
First pass metabolism
A
- Oral Medications, must traverse the intestinal epithelium, the portal venous system, and the liver prior to entering the systemic circulation
- While in the intestine, the drug may undergo metabolism, be transported into the portal vein, or undergo excretion back into the intestinal lumen.
- Both excretion into the intestinal lumen and metabolism decrease systemic bioavailability as well as.
- Drug uptake into the liver, can further limit bioavailability by metabolism or excretion into the bile.
- This elimination in intestine and liver, which reduces the amount of drug delivered to the systemic circulation, is termed presystemic elimination, presystemic extraction, or first-pass elimination.
4
Q
Half life
A
- Most pharmacokinetic processes are first-order - The rate of the process depends on the amount of drug present.
- Half-life is the time required for 50% of a first-order process to be complete. - Thus, 50% of drug elimination is achieved after one drug-elimination half-life, 75% after two, 87.5% after three, etc
- The elimination half-life not only determines the time required for drug concentrations to fall to near-immeasurable levels after a single bolus, it is also the key determinant of the time required for steady-state plasma concentrations to be achieved after any change in drug dosing
5
Q
Steady State
A
- Steady state describes the situation during chronic drug administration when the amount of drug administered per unit time equals drug eliminated per unit time.
- With a continuous intravenous infusion, plasma concentrations at steady state are stable,
- Chronic oral drug administration, plasma concentrations vary during the dosing interval but the time-concentration profile between dosing intervals is stable
6
Q
Can nitroglycerin be used orally?
A
No, because it is completely extracted prior to reaching the systemic circulation
7
Q
intravenous vs oral
A
- Some drugs with very extensive pre-systemic or first pass metabolism can still be administered by the oral route, but much higher doses are required than those for intravenous administration.
- Atypical intravenous dose of verapamil is 1–5 mg, compared to the single oral dose of 40–120 mg.
8
Q
Temporal characteristics of drug effect
A
- A lag period is present before the plasma drug concentration (Cp) exceeds the minimum effective concentration (MEC) for the desired effect.
- Following onset of the response, the intensity of the effect increases as the drug continues to be absorbed and distributed.
- This reaches a peak, after which drug elimination results in a decline in Cp and in the effect’s intensity.
- Effect disappears when the drug concentration falls below the MEC
9
Q
Physiology review facts
A
- Receptors are generally proteins
- Embedded into cell membranes or intracellular
- Generally extend on both sides
- Facilitate communication between 2 sides
- Always causes a secondary effect
- (Remember G proteins and secondary messengers)
10
Q
Agonist
A
- binds specifically
- activates cell funciton
11
Q
Antagonist
A
- binds specifically
- blocks agonist
- does not influence cell function
12
Q
Antagonism
A
- A non-competitive antagonist binds to an allosteric (non-agonist) site on the receptor to prevent activation of the receptor - Doesn’t compete for same site, but still prevents activation
- A competitive antagonist binds to the same site as the agonist but does not activate it, thus blocks the agonist’s action. - Competes for same site, but still prevents activation
13
Q
Hypertension
A
•Treat to BP <140/90 mmHg or BP <130/80 mmHg in patients with diabetes or chronic kidney disease.
- Majority of patients will require two medications to reach goal.
- Thiazide-type diuretics if initial medication for most. May consider ACEI, ARB, BB, CCB depending on patient comorbidities.
- Emerging evidence to suggest ACEI as initial drug therapy for HTN
- 2-drug combination for most (usually thiazide type diuretic and ACEI, or ARB, or BB, or CCB).
•MAP approx= CO ×SVR
14
Q
Diuretics
A
Goal is to reduce blood pressure by reducing blood volume
- 3 most comon types
- Loop
- Thiazide
- Aldosterone Receptor antagonists
15
Q
Loop diuretics
A
block the Na+/K+/2Cl-resorption in the loop of Henle, high ceiling
- Most common: Furosemide (Lasix), drug of choice for HF and patients with CAD w/CKD
- Side effect: Hypokalemia, Hyponatremia, volume depletion, frequent voiding
16
Q
Thiazide diuretics
A
block Na+ reabsorption in the distal tubule of nephron
- Most common: hydrochlorothiazide “HCTZ”, (Esidrix), 1st drug of choice for essential HTN
- Side effect: Hypokalemia, Hyponatremia, volume depletion, frequent voiding
17
Q
Aldosterone receptor antagonists diuretics
A
Blocks Aldosterone and thus Interferes with Na-K+ exchange at distal tubule”aka Potassium Sparing Diuretic)
- Most common: Sprirolactone,(Aldactone)
- Side effect: Volume depletion, frequent voiding
18
Q
Sympatholytics
A
- beta blockers
- alpha 1 blockers
- alpha 2 agonists
19
Q
beta blockers
A
- olol
•Primarily target Beta-1 receptor cites, effects
•Reduces HR
•Reduces BP primarily by reducing contractility
•Reduces sympathetic tone
•Also has antiarrhythmic properties
•In low doses actually functions as an anti-anxiety medication
•Limits adverse ventricular remodeling (dilation) after MI
