Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
What are the 4 pharmacokinetic processes?
|
1. Absorption, 2. disribution, 3. metabolism, 4. excretion
|
|
Define: pharmacokinetic processes
|
Action of body on drug
|
|
CT
|
Target drug concentration in plasma
|
|
CSS
|
Steady state of target drug concentration in plasma
|
|
F
|
F = Bioavailability = Fraction(%) of administered drug that reaches the systemic circulation via a given route(IV route F =1 then measure everything against this)
|
|
Equation for amt of drug reaching systemic circulation?
|
F * Dose
|
|
Is there an absorption component in IV dose?
|
No b/c ur injecting it right into the blood thus F=1 (100% fraction)
|
|
What is the first pass effect?
|
Amount of drug that is broken down when drug is absorbed thru gut and remaining (stuff that isnt broken down) that passes thru the liver
|
|
What is the rate dependent upon for intramuscular(IM) injections
|
Rate dependent on drug form and solubility (lipid/water)
|
|
What is the MOA of prolonged release medication?
|
Rate of PO absorption depends upon drug rates of dissolution in GI tract (ie how fast it gets absorbed) -> results in slow, uniform absorption of drug for 8 hrs or longer; the less frequent adminstration needed -> ↑ patient compliance
|
|
What are the advantages of a prolonged release medication?
|
1. Less frequent administration, 2. therapeutic effect overnight, 3. less incidence/severity of side effects, 3. patient compliance
|
|
Inhalation drug administration advantages
|
1. Drug delivered to target organ, 2. lungs = large surface area -> good absorption, rapid onset, short duration;
|
|
Topical drug administration advantage?
|
Localized site of action thru intact skin; ie nicotine patches
|
|
Define: parenteral drug administration
|
Route other then through GI tract (usually injection)
|
|
What are the advantages of IV + IA drug administration?
|
IV (intravenous) - no absorption needed + dose titration of anesthesia; IA(intra-arterial) - used for anti-cancer agents + diagnostic uses
|
|
Buccal + sub-lingual advantages?
|
are directly absorbed into the systemic circulation -> fast + bypasses first pass effect cuz it doesn't go thru the liver first
|
|
Rectal advantage? Disadvantage?
|
Good if patient is vomiting or unconscious - 50% of drug absorbed by rectum will bypass liver. Disadvantage - irregular absorption, rectal irritation
|
|
What is the limitation of enteral route of drug administration?
|
Drug inactivated by digestive enzymes; incomplete clinical conditions (vomiting, unconsciousness), blood flow, surface area; drugs that are unable to be absorbed thru GI tract
|
|
How do u calculate new dosage(utilizing bioavailability)?
|
(Dose of new form = dose * F of current form)/(F of new dosage form)
|
|
36 yo patient is currently receiving 2 mg daily of erythromycin IV for his whooping cough. He is being discharged and will switch to erythromycin PO. About how much will he have to take by mouth to equal his current IV dose? F=0.35
|
(1 * 2)/.35 = 5.7143 ~ 6mg
|
|
What is the first pass effect?
|
Amount of drug that is broken down when drug is absorbed thru gut and remaining (stuff that isnt broken down) that passes thru the liver
|
|
Per os(PO)
|
Taken by mouth
|
|
Is there an absorption component in IV dose?
|
No b/c ur injecting it right into the blood thus F=1 (100% fraction)
|
|
How to calculate bioavailability using a graph?
|
Area under curve Oral dose/ area under curve IV dose = Fraction %
|