Chapter 3 Flashcards
what is pharmacokinetics
examines how the drug is modified and moved within the body
what are the four processes of pharmacokinetics
Absorption
Distribution
Metabolism
Excretion
what is absorption
The process of moving the drug from the site of administration to the blood stream
what are the three ways that drugs reach the target tissues
Simple diffusion
Facilitated diffusion
Active transport
What are three factors that make a drug more likely to cross the plasma membrane
Small molecule size
Nonionized
If the drug is lipophilic
what is one of the most important variables that affects absorption
Route of administration
what are the three broad categories of routes of administration
Enteral
Topical
Parenteral
What is the enteral route of administration
Drugs are delivered to the GI tract
what are three medications that should not be chewed crushed or opened
Extended release drugs
Enteric coated drugs
Oral cavity drugs
What is the first pass effect***
when drugs are administered enterally they first have to pass through the liver where they may be inactivated before they ever reach the target organ
if a patient was prescribed both an oral medication and a sublingual medication which medication would you administer first
always administer the oral medication first
are medications administered sublingually or buccally subjected to stomach acid or the first pass effect
no
if medication is administered rectally does it go through the first pass effect***
NO
how are parenteral drugs administered
Intradermal (into dermis)
Subcutaneous (into the Subcutaneous layer)
Intramuscular
Intravenous
what is the most dangerous form of parenteral drug administration
IV administration
how does food being in the stomcah affect absorption
food being present in the stomach could slow absorption due o lower motility and a change in PH
would a weak acid like aspirin absorb better in an acidic or basic environment
absorbs better in an acidic environment
how can body pH affect drug absorption
If a drug is an acid and the body pH is acidic the drug will absorb more and same with a base
what is drug distribution
describes how drugs are transported throughout the body
can drug protein complexes cross capillary membranes
NO drugs have to be unbound to reach target tissues
what are the two special barriers that affect drug distribution
Blood brain barrier
Fetal placental barrier
what kind of drugs are able to cross the blood brain barrier
lipid soluble drugs
what is metabolism
The process in which a drug is chemically changed by the body
what are pro drugs
Medications that require metabolism to produce therapeutic actions
