Pharmacokinetics: how drugs are processed by the body Flashcards
What is the process of drug taking?
Absorption
Distribution
Metabolism
Excretion
In what ways can drugs be administered in the body?
Orally; inhalation; injection, transdermal ; buccal ; rectally
In what doses can drugs be administered in the body?
low-high, short/acting-long/acting, acute-chronic
How are drugs distributed throughout the body?
numerous membrane and barriers to drug distribution. Cell membranes, blood capillary, placenta, blood-brain barrier.
How can drugs be metabolised and eliminated from the body?
liver & kidneys (age related decline in drug breakdown… implications?); metabolite and half-lives
What is absorption?
describes the process by which the drug enters the blood circulation
Alcohol is mainly absorbed through diffusion where?
the stomach (20%) and small intestine (80%)
What is diffusion?
Alcohol is mainly metabolised by what?
The liver
It is additionally metabolised in the brain (extrahepatic tissue) and stomach (Cederbaum, 2012)
what enzymes are involved in Metabolic mechanisms of alcohol?
the enzymes involved are aldehyde dehydrogenase (ALDH), alcohol dehydrogenase (ADH), cytochrome P450 (CYP2E1), and catalase
An average sized adult metabolises about ……….g (approx 1 unit) of alcohol per hour.
about 6-8 g (approx 1 unit) of alcohol per hour.
What is the maximum amount of alcohol that can be metabolised in one day?
150 – 200g (approx 25 units).
What is the t½ life of alcohol?
around 1-3 hours
What is the t½ life of alcohol determined by?
by the rate of absorption and metabolism.
What % of alcohol is metabolised through the liver?
What happens to the remaining 10%?
90% of alcohol
The rest is lost through perspiration, stomach lining, urination and exhalation.
