Pharmacokinetics Flashcards
What does ADME stand for?
Absorption, distribution, metabolism and excretion
What is Pharmacokinetics?
The study of how drugs are absorbed, distributed, metabolised and excreted in the body
What factors can influence drug behaviour?
Weight, age and organ function.
What are the physiological factors that impact absorption?
The blood flow to absorbing sites, the total surface area for absorption, the time of arrival and contact time at absorption sites.
What are the physio-chemical factors that impact absorption?
The soluble stability, the chemical stability, the lipid to water partition coefficient, the degree of ionisation and exercise
Where do drugs get distributed to first?
Bodily fluids such as plasma, extracellular and intracellular fluid
What are the two main physiological barriers that drugs have to go through?
The placenta and the blood brain barrier.
What does bio-availability indicate?
It indicates the fraction of an orally administered dose that reaches the systemic circulation as intact drug
Where is a drug metabolised and excreted from?
Liver (metabolism) and kidneys (excretion)
What is phase one of metabolism?
The breakdown of the drug by CYP450 enzymes
What can inhibit the activity of CYP450 enzymes?
Cranberry juice
What is another name for liver cells?
Hepatocytes
What are 3 factors that effect excretion?
Impaired renal function, drug interactions and lipid solubility
What can cause altered kinetics?
Hepatic or renal impairment, reduced elimination, extended half life and drug action at unintended sites.
