Basic pharmacology Flashcards
What are the two divisions of pharmacology
Pharmacodynamics
Pharmacokinetics
What is included in the Pharmacokinetics division of pharmacology
What the body does the to the drug. Including:
-Absorption
-Distribution
-Metabolism
-Excretion
What is included in the pharmacodynamics division of pharmacology
It is the stay of the mechanism of a drug, covers what it does to the body.
What are the 5 main types of drug action
Stimulation - adrenaline
Depression - Alchohol
Irritation - show irritation in certain areas
Replacement - insulin for diabetes
Cytotoxic action - antibiotics
What is absorption in regard to basic pharmacology
The movement of the drug from the site of administration into systemic circulation.
What effect does drug pH have on absorption
Strongly acidic and strongly basic drugs are poorly absorbed. Most drugs are weak acids or weak bases. Acidic drugs are absorbed from the stomach, whereas, basic (alkaline) drugs are better absorbed from the intestine.
What is bioavailability?
It is the fraction of a drug that reaches systemic circulation from a given dose. Term is often used for oral medication.
Oral medicine has a lower bioavailability for example.
The distribution of a drug from the plasma to the extracellular fluid and tissues depends on what?
- Cardiac output
- Binding of drugs to plasma proteins
- Binding of drugs to tissue proteins
- Lipophilicity of the drug
What does the term redistribution mean
Redistribution refers to the change in the plasma drug concentration which is significant enough to cause alteration/termination of drug action.
What does the term biotransformation mean
The chemical alteration of the drug in the body
What is the main site for drug metabolism
The liver
What are some of the sites of drug metabolism
Liver
GI tract
Kidney
Lungs
Blood
Skin
Plasma
What is the main channel of drug excretion?
Kidney
What is are some of the channels of drug excretion
Kidney
Lungs
Faeces
Bile
Sweat
Saliva
Tears
Milk (mothers)
What is the half life of drugs
Half-life (plasma half-life) of a drug means the period of time required for the concentration or amount of the drug in the plasma to be reduced by one-half (50%) of its original amount.
What symbol is used to represent the half life
t½
What is a drug plasmas half life
A drug’s plasma half-life depends on how quickly the drug is eliminated from the plasma.
A drug molecule that leaves plasma may have any of several fates:
It can be eliminated from the body
It can be translocated to another body fluid compartment.
It can be destroyed in the blood
What does plasma half life help to do
Determine the duration of action
Determine the frequency of drug administration
Estimate the time required to reach the steady state (the drug levels in plasma and tissue remain constant)
What are the two type software drug mechanism of action?
Non-receptor mediated mechanism.
Receptor mediated mechanism.
What can non receptor mediated mechanism take place by?
Physical action - osmosis, absorption
Chemical action - antacids
Inhibiting enzymes - angiotensin-converting enzyme inhibitors to help HTN
Antibody production - vaccines
What is receptor mediated mechanism
Receptors are protein on the cell the the drug binds to.
What does affinity mean
The ability of the drug to bind to the receptor.
What is intrinsic activity
The ability of the drug to produce a pharmacological action after binding to the receptor
What is an agonist in regard to basic pharmacology
A drug that can produce a pharmacological action after binding to the receptor
What is a partial antagonist in regard to basic pharmacology
A drug that binds to the receptor but produces an effect less that of an agonist. Usually, it inhibits the effect of the agonist
What is an inverse agonist
A drug that has full affinity toward a receptor but produces an opposite effect to that of an agonist.
