Distribution of Drugs
In regard to the Two Compartment Model, k21 is demonstrating what? (picture from lecture)
k21 = Peripheral --> Central compartment
During which reaction utilizes oxidation, reduction, or hydrolysis to convert substrates?
Phase 1 Reactions (CYP450)
In regard to the body's capacity to eliminate drugs:
A. Directly proportional = ______
B. Inversely proportional = _____
A. Dose
B. Half-Life
From the lecture, what is the one thing that men are more sensitive to than women?
Propofol
After 4 half-lives, how much drug has been eliminated? How much drug is remaining?
Drug eliminated = 93.75%
Drug remaining = 6.26%
Volume of Distribution - Relates to the amount of drug in _______ to ______ concentration
Body to Serum
What is the ultimate goal of drug metabolism?
What two main organs does clearance effect?
Spleen & Intestines
KIDDING...Liver & Kidneys
Pharmacogenomics identifies the drug response at the level of: (3)
Disease, Metabolism, & Target
What are two reasons that a patient might experience CNS toxicity (LAST - local anesthetic systemic toxicity)?
1. Too much local anesthetic administered
2. Mediation accidentally given into an artery or vein > seizure > resp distress
Which drug molecules can cross the BBB, gastric barrier, and placental barrier?
Non-Ionized (uncharged)
*Lipid soluble = cross easily
(A). In first-order kinetics, the greatest amount of drug is eliminated when?
(B). In zero-order kinetics, the greatest amount of drug is eliminated when?
A. Highest concentration (the more drug in your body, your body speeds up the elimination process to get rid of it faster)
B. Constant rate of elimination, no matter the amount in your system your body does not speed up the elimination process (ETOH, phenytoin)
In perfusion-dependent elimination what is the extraction ratio for high-clearance drugs?
greater than or equal to 0.7
T/F: Females experience less respiratory depression with opioids?
False - they experience more
What is the volume of distribution used to calculate?
Loading Dose
Which of the following is NOT an enantiomer?
Cisatracurium, Acetaminophen, Dexmedetomidine, Ropivacaine
Acetaminophen (does not have a mirror-image isomer, all the others do)
If Drug A is an acid compound with a pKa of 7.1 and going into an environment of 6. What is the result?
99% ionized
7.1 - 6 = 1.1 = 99/1 = 99% (acid > more acidic = non-ionized)
Hepatic perfusion does not significantly impact clearance under which elimination rule?
Capacity-Dependent Elimination
With protein binding, which kind of drug would lead to an increased metabolism + elimination rate?
Free drug
When a mother is given Lidocaine, is it because of ionization -or- non-ionization that the medication stays in the system longer before getting metabolized and excreted?
Ionization
*Weak base --> acid = ionization
Of the routes of drug administration, which bypass the first-pass effect?
Sublingual & Buccal, Parenteral, Pulmonary, + Transdermal
Don't bypass the FPE: Enteral, Presystemic, Rectal
The plasma concentration curve is used to determine what?
Half-Life (t 1/2)
pH of urine can impact elimination of drugs, via renal excretion. What are better excreted in:
A. Acidic urine
b. Alkaline urine
a. Weak bases
b. Weak acids
Which of the following is NOT a factor that influences pharmacokinetics?
Being male, having a fever, recent diagnosis of breast cancer, or having CKD
Recent dx of breast cancer
What is the formula for volume of distribution?
Vd = dose / plasma concentration