Introduction and absorption Flashcards
What is pharmacology?
The science-orientated study of drug action
What is the definition of a drug?
A chemical entity of known structure, other than a nutrient/dietary supplement, which causes a biological effect in a living orgainism
What is the definition of a medicine?
A preparation of one or more drug, alongside other substances (stabilisers, solvents, etc.) which is used therapeutically to treat, cure, prevent or diagnose disease,
Give three classifications of drugs
- Molecular structure
- Mode of action
- Therapeutic use
Give an example of a molecular structure name
Catecholamine
Give an example of a mode of action name
Beta-blockers
Give an example of a therapeutic use name
Antihypertensives
Give three ways of naming drugs?
- chemical name
- generic name
- proprietary name
What is the difference between the generic name and the proprietary name for a drug?
The generic name always starts with a lowercase letter, a proprietary name is the trade name and always starts with a capital letter.
What is toxicology?
The study of adverse effects of chemicals on living organisms
What is pharmacy?
Patient-orientated health profession, licenced dispensing medicine, patient monitoring, medicine composition/manufacture.
What are the two main branches of pharmacology?
- Pharmacodynamics
2. Pharmacokinetics
What is the difference between pharmacodynamics and pharmacokinetics?
Pharmacodynamics is what does a drug do to the body while pharmacokinetics is what does the body do to the drug?
What does ADME stand for?
Absorption
Distribution
Metabolism
Excretion
What does delivery of the drug include?
Absorption and distribution
What does drug elimination include?
Metabolism and excretion of the drug
What does ADME determine?
The concentration of the drug at the target site which effects the onset, intensity and duration of the drug’s action
What are xenobiotics?
Drugs, drug metabolites and environmental compounds such as pollutants that are not produced by the body and are excreted
What does distribution entail?
getting the drug from systemic circulation and into the tissues
When does pharmacodynamics start?
When the drug reaches the site of action
Where can the drug go once it is in circulation?
- To be metabolised then excreted
- Directly excreted
- Into tissues
What does absorption entail?
The movement of the drug from the site of administration to the systematic circulation (not to the site of action)
What does ROA stand for?
Route of administration
Give the names for two groups of drug administration
- Enteral (via GI tract)
2. Parenteral
Give 3 examples of enteral administration
- Oral
- Sublingual
- Rectal
Give 7 examples of parenteral administration
- I.V
- Subcutaneous
- Intra muscular (I.M.)
- Inhalation
- Intranasal
- Tropical
- Transdermal
What is different about enteral administration?
Drugs must cross a tight barrier composed of the epithelial cells of the gastrointestinal tract
What is the only route of administration which has 100% bioavailability?
I.V.
What is the rate-limiting step in taking oral drugs?
The dissolution rate
Where are most oral drugs absorbed?
Via the small intestine so large quantities can be absorbed due to the large SA and good blood supply.
What is the draw back of using oral drugs?
It is the most complicated route for a drug to take
What 4 things must an oral drug do before it reaches the site of action?
- Survive gastric acid
- Survive digestive enzymes
- Co-exist with or avoid food
- Cope with gut bacteria
Give an example of a drug hydrolysed by gastric acid
Benzylpenicillin (usually given via I.V.)
Give a solution for oral drugs which can be hydrolysed by gastric acid
Enteric coat for protection
Give an example of a drug which would not be absorbed in the presence of food
tetracycline antibiotics (bind to Ca+, become insoluble and are not absorbed)
Give an example of a drug whose activity is altered by the presence of certain bacterial metabolites
Simvastatin (anti-hypolipidemic drug), sulphasalazine is cleaved into active anti-inflammatory components 5-ASA and sulphapyridine by colonic bacteria
