Week 1- Questions Flashcards
Define pharmacokinetics.
The study of drug movement throughout the body.
The cell membrane is composed of what?
A double layer of molecules known as phospholipids.
Name two ions which can pass through channels or pores.
Na+ and K+
Define transport system. Is it selective or nonselective?
A system which transports drugs from one side of a cell membrane to another.
Only carries drugs with a particular structure.
What type of drug can penetrate a cell membrane?
Lipophilic or lipid-soluble
List two types of non-lipid soluble drugs.
Polar molecules and most ions
Define polar molecule. They dissolve well in what solvent?
Molecules which have an unequal or uneven distribution of electrons yet no net charge.
Water.
Define ion.
Atoms which have a net electrical charge.
An acid tends to ionize in what type of environment? A base tends to ionize in what type of environment?
Base.
Acid.
Explain ion trapping or pH partitioning.
When there is a pH gradient between two sides of a cell membrane, acidic drugs will ionize and stay on the basic side. Basic drugs will ionize and stay on the acidic side. Ionized drugs do not cross cell membranes.
Define absorption.
The movement of drug from its site of administration into the blood.
Rapidly dissolving drugs will have what type of onset?
Rapid.
An increased surface area for absorption will cause absorption to increase or decrease?
Increase.
Drugs are absorbed more rapidly in areas where blood flow is what?
High.
What types of drugs are absorbed rapidly through the cell membrane?
Lipophilic or lipid-soluble
Delayed gastric emptying may delay the absorption of a drug meant to be absorbed where?
Intestines.
Parenteral drugs refer to routes of administration where?
Outside the GI tract.
What is the rate of absorption for intravenous administration?
Instantaneous.
What is the barrier to intramuscular absorption?
Capillary wall.
What types of drugs are absorbed from intramuscular and subcutaneous sites?
Poorly soluble drugs (water-soluble)
Which route is the safest for drug administration?
Oral.
Define chemically equivalent.
Drugs contain the same amount of the identical chemical compound.
Define bioavailability.
Drugs contain the same amount of the identical chemical compound and are absorbed at the same rate and to the same extent.
Where are enteric-coated drugs meant to dissolve?
Intestine.
Why are sustained-release capsules utilized?
Maintain a steady release of the drug all day.
What is the most common mechanism by which drugs enter a cell?
Direct penetration of the membrane
Should enteric-coated drugs be crushed? Why or why not?
No, the drug would interact with stomach acids.
What does the p-glycoprotein do
It is a transmembrane protein which transports drugs out of the cells back into the blood stream or into lumens such as renal tubules or intestinal lumens.
What is a quaternary ammonium compound?
It is a compound with at least one nitrogen atom which has four bonds rather than three bonds. It has a positive charge and is unable to cross most membranes.
