Week 1 Flashcards
What is pharmacology?
the study of medications or chemical compounds that interact with some part of the body
Each drug has at least 3 names. What are they?
- a chemical name based on its chemical structure. Used in scientific studies
- a generic name. Usually the shortened chemical name. Used by health professionals
- the brand/trade names. Given by pharmaceutical companies
What is a drug dose?
the dose is the precise amount of active ingredients in the medication
- dose is combination w inactive substances that help fill out the medication, make it more convenient to use and improve its effectiveness at getting to its target in the body
What are the three phases of drug action?
pharmaceutical → pharmacokinetic → pharmacodynamic
What is the pharmaceutical phase?
how a drug progresses from the state in which it was administered to being dissolved in solution
What are the different ways drugs can be administered?
enteral:
- oral, sublingual, rectal
parental:
- injections (intravenous, subcutaneous, intramuscular)
- inhalation (lungs, nasal)
- transdermal (across the skin)
What factors affect the pharmaceutical phase?
- ability to keep the drug in the body
- pill vs. crushed vs. liquid
- contents in stomach
- timed release
- rate of digestion
What is the pharmacokinetic phase?
the effects of the body on the drug
- 4 subphases for the movement of the drug through the body; impacted by bioavailability
What is bioavailability?
% of drug that enters circulation and gets to its target tissue in active form
Describe the absorption phase of pharmacokinetic
- passive diffuction vs. active transport vs. pinocytosis
affected by: - administrative route (IV most effective; oral < sub < IM)
- blood supply
oral: drug muse go through first pass metabolism
What factors affect the distribution phase of pharmacokinetic
- concentration absorbed
- blood flow to tissue
- % of blood bound to plasma protein (e.g. Albumin)
What is the metabolism phase during pharmacokinetics?
- primarily in the liver
- inactivation by enzymes
- preparation for excretion
- determined the half life of a drug
What is the elimination phase during pharmacokinetics?
- primarily by the kidneys
- also via bile, feces, saliva, sweat, respiration
How does aerobic exercise effect the pharmacokinetics phase?
Absorption: blood flow redistribution to working muscles lowers absorption rate; high intensity ex. decreases gastric emptying
Distribution & Metabolism: redistribution of blood flow = lower metabolic rate
Elimination: redistribution of blood flow = decreased elimination rate in kidneys
What is the pharmacodynamic phase?
the effect of the drug on the body
impacted by:
- therapeutic action
- drug potency
- drug efficacy
What is the therapeutic action of a drug?
- stimulation or inhibition of function
e.g. influences enzyme activity i.e. statins
e.g. binding to cell membrane receptors (agonist or antagonist) i.e. B-blockers
What is drug potency?
the strength of a drug or a particular does (the concentration needed to produce 50% of max effect)
What is drug efficacy?
the maximum effect that be achieved by a drug; reflects the affect of the drug on the receptor once its bound
What is the therapeutic index?
the ratio between toxic dose and minimum effective dose
Toxicity is drug specific. It is determined by…
- chemical properties
- routes & rates of admin
- rates of absorption, biotransformation & excretion
