Chapter 01 - General Pharmacology Flashcards
The movement of molecules from an area of high concentration to an area of low concentration is known as:
Passive diffusion
The primary site for biotransformation is the:
Liver
Based on blood perfusion, which body ‘compartment’ will attain adequate drug
levels first based on an injection into that ‘compartment’?
Skeletal muscle
Parenteral drugs are administered:
By injection
What is dosage?
Mass of drug per unit of weight
25 mg/kg
What is Dose?
Amount to be given each time
Are Pharmaceutical drugs derived from a natural source harmful to the
patient?
Yes
What is bioavailability?
The degree to which a drug is absorbed and reaches general circulation.
Perfusion of tissues:
The greater the blood supply the faster it will absorb
Natural drug barriers:
- Placenta
- Blood Brain Barrier
- Eye
Half Life:
The rate at which a drug is lost from the body
Therapeutic index:
The therapeutic index expresses the relationship between a drug’s therapeutic and harmful effects.
The therapeutic index (TI) is the range of doses at which a medication is effective without unacceptable adverse events.
Drugs with a narrow TI (NTIDs) have a narrow window between their effective doses and those at which they produce adverse toxic effects.
Receptor-mediated Drugs:
bind to receptor sites and cause the cell to react (agonist) or prevent reaction (antagonist)
Non-receptor-mediated drugs:
Chemical, physical, physiochemical modification of body fluid
Agonist:
A drug that has affinity for a receptor and stimulates the receptor to action.
Contraindication:
A contraindication is a reason not to use a drug in a particular situation.
Efficacy:
Efficacy is the degree to which a drug produces its desired effects in a patient.
An over-the-counter drug:
An over-the-counter drug is one that may be purchased and used without a prescription from a veterinarian.
A receptor:
A receptor is a group of specialized molecules on or in a cell that binds with a drug to produce an effect.
Withdrawal time:
The withdrawal time is the amount of time that must elapse between the end of drug therapy and the elimination of that drug from the patient’s tissues or products.
Four sources for veterinary drugs are:
Animal products, plant materials, minerals, and synthetic products.
Four components of a drug regiment ?
A drug regimen includes the dose, the route of administration, the frequency of administration, and the duration of administration.
Sequence of events that a drug under goes from administration to excretion:
A drug is first absorbed (or directly placed) into the bloodstream. In the blood, the drug may bind with a plasma protein or may exist in the free state. The circulating blood distributes the drug to the capillary level, where the drug leaves the circulation and enters the interstitial fluid. The interstitial fluid bathes the cell and allows the drug to enter the cell or bind with surface receptors. The drug then exits the cell (or its surface), moves back into the interstitial fluid, reenters the circulation, and is transported to the liver for metabolism. After it is metabolized, the metabolite is transported to the kidneys for excretion.
Factors that influence drug absorption:
The absorption of a drug may be influenced by (1) the
method of absorption, (2) the pH of the drug and its ionization status, (3) the absorptive surface area, (4) the blood supply to the area, (5) the solubility of the drug, (6) the dosage form, (7) the status of the gastro- intestinal tract, and (8) interactions with other drugs
