pharmokinetics Flashcards
what is clinical pharmacology
science of drugs and their use in humans
what is bioavailability
the proportion of administrated drug which reaches the systemic circulation unchanged
what type of drug administration achieves 100% bioavailability
intravenous injection
what is the most common route of drug administration
oral route
in the oral route what does absorption rate depend on
GI transit
what are the mucosal routes of drug administration
nasal, eye, vaginal, rectum,
what route of administration avoids first pass metabolism
inhalation, mucosal routes, transdermal, intravenous subcutaneous and intramuscular injections
what is pharmacokinetics
study of drug movement within the body
what is pharmacodynamics
study of drug effects and metabolism of action
what are the four stages of pharmacokinetics
absorption, distribution, metabolism, excretion
For an orally- administrated drug to reach
systemic arterial circulation intact, the drug must :
- cross the GI tract
- avoid metabolism by the GI tract and liver
factors affecting GI drug absorption rates
- Surface area and blood flow
- Gastrointestinal motility
- Malabsorptive tates
- food type
what is first pass metabolism
the extent of metabolism occurring BEFORE the drug enters the systemic circulation. Occurs in gut lumen, gut wall and liver
after absorption orally-administrated drugs enter what system
portal system
rate and distribution of a drug are determined by
- the ability of the drug to pass through membranes
- lipid solubility Of the drug
- Binding of the drug to plasma proteins
- active transport across cell membranes
- Presence of other drugs in the body