Exam 1 Pharmacokinetics Flashcards
Lecture 3
List the steps of the life of a drug in the body
- Route of administration
- Absorption
- Distribution
- Metabolism (changed so can be extracted)
- Excretion
What are the 3 routes of administration?
- Enteral
- Parenteral
- Topical (type of parenteral)
____ uses the gastrointestinal tract for ingestion
Enteral
What route avoids the GI tract?
Parenteral
Topical is also a ____ route
Parenteral
Topical drugs can be applied to:
Skin or mucous membranes
Once a drug enters the body via enteral route, what happens?
- Absorbed from stomach/intestine
- Goes to the liver (first pass effect)
- Distributed to the rest of the body
What is the first pass effect?
Most blood supplying the GI tract travels to the liver before going to the rest of the body (portal system), often inactivating drugs
What organ is metabolic (change) machine?
Liver
What is the pathway a drug takes in the enteral route?
- Goes to lumen of GI tract
- Enters hepatic portal system (capillaries –> hepatic portal vein)
- Liver (metabolizes drugs)
- General circulation
Special points of the enteral route
- Sublingual
- Rectal
What point in the enteral route has rapid absorption of certain drugs?
Sublingual
True or false: Sublingual route still has first-pass drug metabolism in the liver
False - avoids first pass
Is rectal route systemic?
Yes
____ is useful for when pt has nausea/vomiting
Rectal route
Enteral route special point
True or false: rectal has relatively little first-pass metabolism
True
Examples of parenteral routes
- Subcutaneous injection
- Intramuscular injection
- Intravenous injection
- Transdermal
- Implantation
- Intrathecal injection (into CSF/spinal cord)
- Intra-articular injection (arthritis)
- Inhalation
- Topical
All forms of injections (IM, SQ, IV)
Topical administration can be given through a ____
Transdermal patch (Scopolamine for motion sickness)
In a transdermal patch, dose is ____ to the area of the patch
Proportional
Distribution of transdermal patch depends on what?
Blood flow
Inhalation involves:
Gases or solid/liquid particulate aerosols
What is used for an acute allergic reaction?
Epinephrine aerosol
The more layers between the site of administration and the bloodstream, the ___ the rate
Slower
Rank order of routes from slowest to fast - IM, SQ, oral
Oral < SQ < IM