INTRODUCTION TO PHARMACOLOGY Flashcards
The science concerned with history, sources, physical, chemical properties of drugs, and ways in which drug affect biological systems
pharmacology
Are chemicals that are introduced into the body
drugs
Science of preparing, compounding, and dispensing medicines
pharmacy
Identification and preparation of crude drugs from natural sources
pharmacognosy
Study of poisonous aspect of drugs
toxicology
- Branch of pharmacology that uses drugs to treat, prevent, and diagnose diseases
- aka Clinical pharmacology
pharmacotherapeutics
- How the drugs are affected by the biological system
- What the body does the drug
pharmacokinetics
- Effects of drugs in biological systems
- What the drug does to the body
pharmacodynamics
Chemical structure of the drug
chemical name
Official nonproprietary name of drugs, universally accepted.
generic name
Proprietary name, chosen by drug company
brand / trade name
5 sources of drugs
- plant
- mineral
- animal
- synthetic
- microorganism
drug development:
To know if substance has potential to become a drug
in vitro studies
drug development:
We check if drug is efficacious, if there is any selectivity for it to exert its effect
animal testing
clinical trial:
- Concerned with pharmacokinetics of drugs
- Limited no. of healthy participants (20-100)
- To know if drug is safe
phase 1
clinical trial:
- Does it work in patients?
- Subject has disease
- 100-200 participants
phase 2
clinical trial:
- Does it work double blind?
- 1000-6000 patients
-Nurse and patient does not know if it is the trial drug they’re testing to check if it is still working
phase 3
clinical trial:
- Postmarketing Surveillance
- Can last for a long time (10-20 years)
- Adverse reactions for long time use
phase 4
Needs to be prescribed first before acquired
prescription drugs
Can be bought even without prescription
OTC drugs
Not yet done with clinical drugs
investigational drugs
- Prohibited substances
- Should not be sold to the public because of addictive effects
illicit / street drugs
Sometimes some of the drugs once absorbed by tissues can also go back to the blood
re-distribution
The processes of entry of a drug into the systemic circulation from the site of its administration
absorption
- Majority of drugs used clinically use this transport
- Direction of movement of solutes is downstream
passive diffusion
- Higher to lower concentration
- These substances are large enough, polar, or ionized that they need a gate for them to be able to enter inside cell
facilitated diffusion
Will be able to move substance from lower to higher concentration by using ATP
active transport
Utilizes large drug molecules for it to be able to enter cell
edocytosis
GI tract -> Portal Circulation -> Systemic Circulation
first pass hepatic metabolism
the measure of the fraction of a dose that reaches the systemic circulation
bioavailability
___ doses have 100% bioavailability
intravascular
Process wherein drug reversibly leaves the bloodstream and enters the target organ
distribution
___ is not an active/true receptor, but once drug binds to it, drug will not be able to exert its effect, hence it will be inactive
albumin
___ drugs contain phenyl hydroxide and cross blood brain barrier
-phen
Most low molecular weight medicines cross the ___
placenta
Permeable only to lipid soluble or low molecular weight drugs
blood brain barrier
Is the metabolic conversion of drug to more water soluble metabolites that are more readily excreted
metabolism
main organ of metabolism
liver
metabolism:
- reduction, oxidation, hydrolysis
- goal: make drug more water soluble but still in active form
phase 1
metabolism:
- methylation, glucuronidation, acetylation, sulfation
- Drugs metabolized here are given to older patients
- goal: make drug more water soluble with the hope of it to be inactive
phase 2
- Primarily found in liver
- Primary phase I enzyme system involved in the oxidative metabolism of xenobiotics
- Responsible for metabolism and synthesis of endogenous compounds like steroids and prostaglandins
cytochrome p450 system
Termination of the drug
elimination
main organ of elimination
kidneys
It is the time to eliminate 50% of a given amount of drug or to decrease plasma level to 50% of the former drug level
elimination half-life
- Filtration is not saturable
- Ionized and nonionized are filtered but protein bound drugs are not
- Acidification and alkalinization happens in reabsorption
renal elimination
- Constant AMOUNT of the drug is eliminated per unit time
- Rate of elimination is independent of plasma concentration
- fixed; no half-life
zero order kinetics
Drug enters the plasma and lasts until it reaches the minimum effective concentration (MEC)
onset of action
Drug reaches its highest blood or plasma concentration
peak of action
Length of time the drug has a pharmacologic effect
duration of action
The concentration level a drug must reach in order to exert its intended effect
minimum effective concentration
the concentration need to reach for drug to exert safe effects
therapeutic window
Ability of the drug to bind to the receptor. How good the drug and the receptor recognize each other
affinity
The quantity of the drug to achieve a desired effect
potency
Maximal effect an agonist can achieve at the highest practical concentrations
efficacy
A drug binding to receptors will elicit a response
agonist
A drug binding to a receptor will elicit no response and it prevents the agonist from binding to the receptor
antagonist
Fraction of the population that responds at each dose against the log of the dose administered
quantal dose response curve
50% of population will be able to get effect from drug
Median effective (ED50)
50% of population will have its toxic effects at this specific dose
Median toxic (TD50)
50% of population will die
Median lethal (LD50) doses
Measurement of drug safety
therapeutic index
Are physiologic effects of drugs not related to desired drug effects, may be desirable or undesirable.
side effects
Are a range of untoward effects of drugs that cause mild to severe side effects
adverse reactions
FDA:
No evidence of risk
category a
FDA:
Animal studies have shown an adverse effect, but adequate studies in pregnant women have not demonstrated a risk to the fetus.
category b
FDA:
There are no animal reproduction studies & no adequate studies in human.
category c
FDA:
Evidence of human fetal risk, but the potential benefits from the use of the drug in pregnant women maybe acceptable.
category d
FDA:
Evidence of fetal risk and abnormalities
category x
- Self-determination
- Before giving drug, px must be able to choose if they’d take the drug or not
autonomy
- through truth telling
- What px should know, before, during, and after taking drug
veracity
do no harm
non-maleficence
prevent harm, do good
beneficence
Give to each person his/her right or due
justice
Not to divulge information without consent
confidentiality
Different treatments, there is beneficial and harmful effect beneficial should outweigh harmful
double effect
An act to promote, require and ensure the production of an adequate supply, distribution, use and acceptance of drugs and medicines identified by their generic name
RA 6675 (GENERICS ACT OF 1988)
- All prescriptions must contain the following information: Name of the prescriber, office address, License no., Professional Tax Receipt (PTR) No., Patient’s name, age, sex and date of prescription
- Include drug name (generic name), dispense number, label or signature (tells how drug should be given to patient)
RA 5921 (PHARMACY ACT)
Act that states which drugs are prohibited in the country (recreational/illegal drugs)
RA 6425 (DANGEROUS DRUGS ACT OF 1972)
10 rights in drug administation
- client
- drug
- route
- dose
- time
- to education
- assessment
- documentation
- evaluation
- to refuse
