What is pharmacokinetics
what the human body does to the drug
What is pharmacodynamics
what the drug does to the body
When a drug is given IV, what is not required?
absorption
Most drug absorption occurs in the
small intestine because of the large surface area and permeable membrane
After gut absorption, the drug enters the
portal vein and travels to the liver
Define passive diffusion
movement of drugs from an area of high concentration (the gut) to an area of lower concentration (the blood)
Active transport occurs when
drugs are moved across the gut wall via transporter proteins that are normally used to absorb nutrients from food
Define disintegration
when a solid oral dosage breaks into smaller pieces in the GI tract
The smaller pieces in the disintegration process then dissolve and the active ingredient is released from the dosage from, this process is called
dissolution
The rate of dissolution is called
Noyes-Whitney equation
SL and ODT formulations generally have
fast absorption
Rate of absorption by dosage form (fastest to slowest)
IV --> SL --> ODT --> immediate-release tablet --> ER tablets
Define bioavailability
extent of drug absorption into the systemic circulation
Bioavailability is reported as a percentage and reflects the
percentage of drug absorbed from extravascular (oral) compared to intravascular administration (IV)
A drug with good absorption has _______ while a drug with poor absorption has _____
high bioavailability (> 70%), low bioavailability (<10%)
What is the calculation for absolute bioavailability
F%= 100 x AUC extravascular/AUC intravenous x Dose intravenous/ Dose extravascular
Define distribution
NOT DONE