Flashcards in TEST #4 Pharmacology part II 11/29/16 Dr. Flekenstein Deck (43):
The concentration of a drug at a particular site is not related to its affinity
It is related to its affinity
The initial distribution of drug into tissues is determined by what?
Rate of blood flow
What is a topical drug?
-A drug that is applied to a surface
Plasma binding proteins and gastric emptying time can play a role in the effect of a drug
What is transdermal administration?
-A patch that releases slowly
What is a synonymous term for therapeutic range?
What is a substance that brings about a change in biologic function through its chemical actions?
What is a subset or compound of drugs used for selective, therapeutic effects?
What are chemicals not synthesized in the body?
What is it called when you have unintended effects from a drug?
What are four factors that effect the absorption of drugs in the blood?
-Route of administration
-Cell membrane characteristics
What are four important characteristics of drugs that deal with membrane diffusion?
-Whether the drug is lipid soluble or water soluble
-size (large vs small)
Formulation, concentration and acidity are all important considerations to make when looking at drug characteristics.
What type of drugs are only soluble in lipids?
What is the fraction of unchanged drug reaching the systemic circulation following administration by any route?
If you do an intravenous injection what is your bioavailability?
What can effect bioavailability of a drug?
-Drug dissolving in GI tract
-Drug destruction by liver
What is the measure of the apparent space in the body available to contain a drug?
-Volume of distribution
How do you measure the volume of distribution?
-V= Amount of drug in body / concentration
If you have a Vd of 3 L what does that mean?
-Drug stayed mainly in the plasma
If you have a Vd of 14 L what does that mean?
-Drug was distributed into the extracellular space
If you have a Vd of 42 L what does that mean?
-Drug was distributed into all of the total body water
If you have an extremely high Vd such as 300 L what does that mean?
-The drug has accumulated into the fat
If you have drugs with small volume of distribution what does that mean?
-Drugs are limited to certain areas within the body
If you have drugs with a large volume of distribution what does that mean?
-The drug penetrates extensively into tissues throughout the body
What do you use to calculate half life?
-Volume of distribution
What is clearance of a drug?
-Rate of elimination
How are drugs generally eliminated?
What are four places in the body that SLC and ABC transporters are used?
What do p-glycoproteins do?
-Transport drug molecule from cells back into the intestinal lumen for excretion
What order of drug is it if a constant amount of drug is eliminated per unit time?
Zero order drug is a process that takes place at a constant rate independent of drug concentration involved in process
What order of drug is it when the process that is directly proportional to the drug concentration involved in process?
What does metabolism of a drug mean?
-A change in the drug
When you metabolize drugs what happens to its activity?
-Generally goes inactive but can sometimes become more active
What does Phase I of hepatic metabolism mean?
What type of phase I metabolites are excreted?
-Hydrophilic metabolites all others go to phase II
Cytochrome p450 is associated with microsomes
What is a key molecule for drug metabolism (oxidation), biotransformation, and detoxification?
When you have something that increases the activity of a particular p450 enzyme and thus increases metabolism and clearance of a drug what is that called?
When you have something that inhibits the activity of a particular p450 enzyme and thus decreases metabolism and clearance of a drug what is that called?
What occurs in phase II of hepatic metabolism?
-Conjugation that makes the drug more hydrophilic