Week 1 reading Flashcards
What is pharmacokinetics
The study of how the human body interacts with a drug
What is the study of how the human body interacts with a drug called
pharmacokinetics
What are the 3 mechanisms of pharmacokinetics
Absorption
Distribution
Metabolism/Eliminatoin
What is Pharmacodynamics
The study of the effects of a drug and its MOA
The study of the effects of a drug and its MOA is called what
pharmacodynamics
What are the 3 pharmacodynamic areas of study
Drug receptor binding dynamics
MOA of the drug
Physiologic response
If you are studying drug administration, are you studying pharmacodynamics or pharmacokinetics?
Pharmacokinetics– how the body interacts with the drug
If you are studying drug absorption, are you studying pharmacodynamics or pharmacokinetics?
Pharmacokinetics
If you are studying drug distribution, are you studying pharmacodynamics or pharmacokinetics?
Pharmacokinetics
If you are studying drug efficacy, are you studying pharmacodynamics or pharmacokinetics?
Pharmacodynamics (the response to the drug)
If you are studying drug affinity, are you studying pharmacodynamics or pharmacokinetics?
Pharmacodynamics– how the drug binds to the molecular target
If you are studying drug MOA, are you studying pharmacodynamics or pharmacokinetics?
Pharmacodynamics
Absorption is the transfer of a drug from where to where
From the site of administration to the bloodstream
What impacts absorption into the bloodstream
The drug’s physical and chemical properties( including lipid solubility, particle size, and degree of ionization)
The drug’s forumulation
Route of admininistration ( Oral, IV, IM)
What are some of the ways that Absorption through the GI tract is affected
Luminal pH values in the GI tract
Surface area (small intestine is largest SA and most absorption occurs here)
Blood flow and perfusion (Decreased due to shock reduces absorption)
Where does most absorption occur in oral routes of administration
Small intestine
What type of administration did you give a patient if you are concerned about absorption through the GI tract?
Oral administration
How do drugs cross the epithelial membranes in the GI tract?
Passive diffusion depending on the concentration, or facilitated passive diffusion(no energy use), active transport, or pinocytosis using energy.
If you have a a lipid soluble drug, does that diffuse more or less readily across a membrane?
More– membranes are lipid, so lipid-soluble diffuse readily
Do smaller or larger molecules diffuse more easily across a GI tract membrane
smaller diffuse easier
Which type of diffusion requires a carrier molecule
Facilitated passive diffusion
Which type of transport do vitamins, sugars, and amino acids use (similar to endogenous substances)
Active transport, can occur against a concentration gradient and requires energy.
If you are transporting a drug using vesicles, what type of transport are you using
Pinocytosis, requires energy
What is the extent and rate at which a drug enters systemic circulation called
bioavailability– only for oral drugs, IV drugs have 100% bioavailability.
Which type of route of administration is Bioavailability relavent for
Oral– IV has 100%
What factors affect bioavailability
Anything affecting absoprtion, hepatic 1st pass metabolism(drugs from GI tract go to liver), enterohepatic circulation( drugs taken up by liver are excreted in bile and then into intestine, released, and taken up again)
Which concept is the reason behind why there can be multiple peaks in the drug’s plasma concentration
Enterohepatic circulation– the drug can be absorbed by the GI tract and taken up by liver, and then excreted in bile, and then reabsorbed in the intestine to restart the cycle.
What is the extent to which a drug is transported from systemic circulation to target tissues and organs called
distribution
What general factors affect a drug’s distribution?
Tissue permiability depends on a drug’s size and pKa, or if they are hydrophillic or hydrophobic
Tissue barriers (BBB, placental barrier, Blood-testis barrier)
Cardiac output
Body composition (adopose affects volume)
Age (body water higher in infants, immature NS causes more distribution into the brain)
Sex ( Women have less total body water and more fat)
Pregnancy
Diet (high fat diets compete with drugs to bind to albumin)
Drug interactions (2 drugs compete for same binding site)
The body chemically changing drugs into different molecules to make them pharmacologically active or to eliminate them is what concept
Biotransformation
Metabolism is a type of what
biotransformation
Where does biotransformation typically occur
in the liver
If your hepatic enzymes are decreased, which pharmokinetic action will your body have difficulty completing
biotransformation(directly)
also probably bioavailability though because of hepatic circulation
Describe phase 1, 2, and 3 biotransformation reactions
- drug–>polar metabolite so its water soluble
- conjugate metabolite
- Process drug using transport proteins
If p450 enzyme is inhibited or induced, which phase reaction is changed in biotransformation?
phase 1 (uses cytochrome P450 in liver)
Which factors impact drug metabolism
CYP450 differences/inhibition/induction/competative inhibition with drugs using the same pathway
1st order kinetics vs 0 order kinetics rate of metabolism
0- metabolism occurs at maximal rate, does not change in porportion to drug concentration
1- metabolism rate increases with drug concentration
What are macromolecules involved in chemical signaling between and within cells called
receptors
Where are receptors located
Cell surface (g protein, ion channels) or Intracellular (steroid receptors, vitamin A)
A drug’s ability to affect a receptor is related to what 2 properties
- Affinity ( attraction to the receptor)
- Efficacy ( degree to which a response is made)
What is drug effect modulated by
the presence of antagonists and the affinity to the molecule receptor
Primary organs for metabolic elimination vs excretory elimination of drugs
metabolic- liver
kidney- excretory
What was the overall difficulty with L- Dopa?
Caused GI side effects as increased the dose, as it is converted to dopamine in other parts of the body (The GI tract) too
What was the drug that addressed the issue with levodopa?
Carbidopa– inhibits levodopa to dopamine, decreasing rates of nausa, and doesn’t cross BBB so the brain still converts levodopa to dopamine
Which enantiomer is the active form of DOPA
L Dopa
Where did SINEMET come from
Sine- without
EMET- vomitting (no vomiting with levodopa and carbodopa together)
Why is Lasix named Lasix
(LA)sts SIX hours (lasts 6 hours)
What is Warfarin named after
Wisconsin Alumni Research Foundation
What is Nystatin named after
NY state health department
Protonix and Prevacid
Protonix (nixes proteins)
Prevacid (Prevents acid)
