Therapeutic Principles. Flashcards
What does the word therapeutic mean?
The act of treating a disease or disorder through the use of healing agents or methods.
What are some examples of therapeutic actions?
Responsible use of antibiotics.
The surgical repair of broken bones.
The drainage of an abscess.
Pharmacology is the study of what?
It is the study of drugs and their interactions with the body.
What are drugs?
Any chemical agent used in the treatment, cure or prevention of a disease.
Does food count as a drug?
No.
What is clinical pharmacology?
A division of pharmacology that studies the effects of drugs on patients.
What is the goal of pharmacology?
To optimise the correct dosage of drugs.
What 2 things are inherent in the study of pharmacology?
Knowledge of the pharmacokinetic properties of drugs.
Knowledge of the pharmacodynamic properties of drugs.
Knowledge of the toxic effects on drugs.
Define pharmo-kinetics?
It is the study of how the drug is absorbed and metabolised by individuals and populations. and deals with the absorption, distribution, metabolism and excretion (ADME) of drugs.
What is the ADME of pharmo-kinetics?
An acronym for what pharmo-kinetics studies in relation to drugs.
Absorption.
Distribution.
Metabolism.
Excretion.
What is the basic idea behind pharmo-kinetics?
How the body affects the drug.
What is the study of pharmacodynamics?
It is the study of the biochemical and physiological effects of drugs on the body.
What is the basic idea behind pharmacodynamics?
How the drug affects the body.
What must happen to a drug before it can have any effects?
The drug must be absorbed into the body.
What are the 3 physiological components of drug absorption?
The blood flow at site of absorption.
The total surface area for absorption.
Physical and chemical properties of the drug.
What are the 4 physical and chemical properties of the drug in respects of absorption?
The solubility of the drug.
The chemical stability of the drug.
The lipid and water partition coefficient.
The degree of ionization.
What is the cutaneous route of drug absorption?
When a topical drug is placed on the skin to be absorbed.
What is the enteral route of drug absorption?
When a drug is administered orally or rectally.
What are the 5 parenteral methods of drug absorption?
Intravenous.
Intramuscular.
Subcutaneous.
Intradermic.
Intramammary.
What is important to take into consideration when administering an intramuscular injection?
The risk of an abcess.
What is the best route for the administration of volatile anesthetics?
Via the respiratory system.
What are the physico/chemical properties of a drug?
Solubility.
Chemical stability.
Lipid/water partition coefficient.
Degree of ionization.
What are 3 physico chemical properties of a drug that should be taken into account in regards to solubility?
Hydrophobic.
Hydrophilic.
Amphipathic.
What are 5 physico chemical property of a drug that should be taken into account in regards to chemical stability?
Galenic formulation.
Light exposure.
Temperature.
Inactive metabolites.
Solubility.
What physico chemical property of a drug should be taken into account in regards to lipid/water partition coefficient?
The transport through biological membranes.
What physico chemical property of a drug should be taken into account in regards to degree of ionisation?
The pH of weak acids and bases.
Local anaesthetic and inflammation
What is the distribution of drugs?
The distribution of the drug into body fluids.
Where are the molecular targets for drugs found?
In the extracellular fluid.
In the intracellular fluid.
Why is it important that the drug is tailored to the target tissue?
Because specific tissues take up some drugs better than others.
Why is it important to consider plasma proteins during the distribution of drugs?
Because some plasma proteins such as albumin can bind drug molecules.
Will a drug have any effect if it binds to a plasma protein?
No.
Drugs bound to plasma proteins are pharmacologically inert.
What kind of drugs will be active within the body?
Free drugs.
What kind of barriers must be taken into account when studying the distribution of drugs?
Biological barriers.
What are the 2 main biological barriers within the body?
The placenta and the blood-brain barrier.
What is the biotransformation of drugs?
It is the process of metabolising the parent drug compound.
Where does the metabolism of drugs usually occur?
In the liver.
What does the liver metabolise different drugs into?
Into different compounds called metabolites.
How can the metabolites of a drug vary when compared to the parent drug?
The can decrease, increase or have no change.
What factor of drug metabolism will contribute to the fequency of a drugs administration?
How many metabolites are formed.
What can change the properties of drugs to facilitate their removal from the body?
Different chemical reactions that are performed by the body.
How are most drugs removed from the body?
Via excretion.
What is the metabolism pattern of most drugs?
Phase I oxidation which is followed by reduction and hydrolysis.
This is then followed by phase II conjugation.
Why do cats tend to display a slow hepatic metabolism?
As they are deficient in several conjugation enzymes.
When should drugs be excreted from the bod?
After they have had their desired effect.
What are the 2 methods of drug excretion?
The elimination and clearance of drugs through the kindeys.
The secretion of drugs into bile for faecal elimination.
What would happen if drugs were not eliminated from the body?
They would accumulate in the bloodstream and this may lead to toxic effects.
Define an agonist?
A drug that binds to and activates a receptor.
Define an antagonist?
A drug that reduces the effect of an agonist.
How does an antagonist reduce the effect of an agonist?
Either competitively or non-competitively.
Are the effects of an agonist or antagonist reversible?
They can either be reversible or irreversible.
Define an inhibitor?
A molecule that binds to an enzyme and decreases its activity.
Define a cellular target?
The location which a drug will exert its effects at.
Where are cellular targets located?
Within body cells.
Within the microorganisms that are infecting the body.
What cellular receptor is often the target of veteinary drugs?
The beta adrenergic receptor.
What ion channel is often the target of veteinary drugs?
Sodium voltage channels.
What are the characteristics of the drug penicillin?
It has a low toxicity.
What condition could penicillin be used for?
An allergy.
What condition could flunixin meglumine be used for?
A gastric ulcer or an acute kidney injury.
What kind of toxicicty do aminoglycosides have?
Ototoxicity and renal toxicity.
How can the toxicity of aminoglycosides be reduced?
By administering a high dose which will saturate the transporters in the kidney and reduce the toxicity.
