01- Drug Administration and Absorption Flashcards
What are the topical routes of administration?
- Skin
- Inhalers
- Eye and ear drops
What does the term enteral mean?
Using/involving the gut to get the drug where it needs to go
What are the enteral routes of administration?
- Oral
- Rectal
What does the term parenteral mean?
Achieving the effect beyond the site of administration, used in highly vascularized areas
What are the parenteral routes of administration? 6
- Intravenous
- Subcutaneous
- Intramuscular
- Transdermal
- Intrathecal
- Sublingual
Which route is the most complex, and why?
Oral, the drug must break down, pass the hepatic portal system, enter the systemic circulation to produce biological effect
How does a bad liver affect absorption?
Decreases the first pass effect and increases risk for overdose
What type of administration would a cream on a rash would be considered?
Topical
What type of administration would administering the drug directly into the bloodstream be considered?
Intravenous
What type of administration would be administering drug under the skin be considered?
Subcutaneous
What type of administration would a vaccine be considered?
Intramuscular
What type of administration would a patch be?
Transdermal
What type of administration would be an epidural be considered?
Intrathecal
Which type of administration bypasses the first pass effect?
Parenteral route
What is drug absorption defined as?
The movement of a drug from its site of administration across body membranes, and into circulating fluids (bloodstream)
Which route of administration is the most direct?
Intravenous, goes right into the bloodstream, no first pass, and no drug lost!
Why (when using routes other than parenteral routes) do we need to increase the amount of drug given then what is needed to produce a biological effect?
Given more drug than what is needed because we assume that some drug will be lost with the first pass effect
What is the issue with giving the patient more drug due to the first pass effect?
If a patient has issues with organs associated with absorption/excretion then there is an increased risk of overdose
What are the factors affecting drug absorption?
- Route of administration
- Drug properties and formulation
- Drug dosage
- Blood flow at the administration site
- Digestive motility
- Digestive tract enzymes
- Intestinal P-Glycoproteins
What are some of the issues associated with drug properties and formulation?
- Drug in liquid form absorbed faster than drug in tablet form
- Some are slow/quick release
- Bind tight/loose
- H20/fat soluble
How does drug dosage influence drug absorption?
Increased concentration gradient causes the drug to move faster
How does blood flow at the administration site influence drug absorption?
No blood flow = no absorption