Pharmacology introduction Flashcards
introduction
What is Pharmacology?
The science of chemicals that effect a living process
what is toxicology?
adverse effects of chemicals
What is drug therapy?
“management” of disease with a medication.
- cure is rare for example antibiotics
what is a drug?
alters an effect already existing in a quatitative manner of changes
1938 Food and Drug Cosmetic Act
- must prove safety
- missing efficacy
1962 Kefaver- Harris Amendment
- Must prove efficacy
- grandfather clause
- any drug before 1962 is exempt.it takes 20 more years for FDA to check grandfather clause
NOTE:
- herbal products not regulated by FDA
- no testing of eficacy
- no purity
- an herbal cannot make claim to treat a disease
when is it require to report?
- chemical or substance not previously used in humans
- new combination not used in combination before
- new use for a previously issued drug
- new dosage form
NOTE:
- Doctors can do whatever they want as long as the drug has been approved
- the drug companies cannot advertise it
How many phases?
4
what is phase 1?
determine safety and tolerated dose in a few “healthy” volunteers
NOTE:
- on animals first
- not to another group who already has the disease
Phase 2
Determine safety, efficacy and pharmacokinetics in selected “diseased” individuals
phase 3
determine safety and efficacy in widespread study
Phase 4
drug marketed with surveillance
what are the types of studies?
Double blind and single blind
Double Blind
investigator and paitent does not know what they are getting very unbiased.
Single blind
Investigator knows whitle the patient does not
NOTE:
- if a patient is in a study and then gets sickthe drug name has to be known to the patient and then they are kicked out of the study
Generic Name
cheimcal name for a medication
NONE CAPITALIZE
trade name
a manufacturer’s name for the generic product
For example: Motrin, Advil
over the counter
non-prescriptive agent
legend drug
prescriptive agent
The behind the counter drug
does not require prescription but need to show infor if buying
- Morning after pill (17 years or older)
- insulin
- sudafed
- antihistamine/ decongestant
Controlled substance
prescriptive agent that has the potential for abuse
NOTE: requires a precription
What act is for the controlled substances?
1970 Comprehensive Drug Abuse and Prevention Act
how many schedules are drugs of abuse divided into?
5
schedule 1
- high abuse potential, little medicinal benefit
- illegal drug
- examples include: heroin, LSD, PCP, Marijuana, rock cocaine
Schedule 2
- high abuse potential, medicinal benefit
- examples include:
- Narcotics: morphine, meperidine, methadone
- stimulats: dextroamphetamine, methylphenidate
- barbiturates: secobarbital, pentobarbital (fast acting barbiturates)
schedule 3
- lower abuse potential, medicinal benefit
- examples include:
- combinations with narcotics: actaminophen with codeine
- testosterones (anabolic steroids)
schedule 4
- Lower abuse potential, medicinal benefit
- examples include:
- benzodiazepines - diazepam, alprazolam (valium and xanax)
- long acting barbiturates: phenobarbital
- propoxyphene ( pulled off the shelf on 2011 but has been on the market for 50 years)
schedule 5
- low abuse potential, medicinal benefit
- examples include:
- cough syrups with narcotics (very diluted)
- Diphenoxylate/ atropine (antidiarrheal agent) (atropine is a anti cholinergic agent)
when to report to the FDA?
- Drug is less than 2 years and a adverse drug reactions on patient occurs
- drug 2 years or more, and an adverse reaction occurs which has never been seen in drug before or serious or life threatening
what are they?
- Degree of Absorption
- volume of distribution
- rate of elimination
Degree of absorption
- Rate from 0%-100% (0=works on intestines =less drug goes on blood stream less side effects)
- depends on route of admistration
- intravenous is 100% absorbed
- some drugs not intended tob e absorbed
- depnds on dosage form
- suppositories are poorly absorbed (rectal very eradict)
Distribution
- ability to cross tissues
- the more tissues crossed the higher the does and the greater the potential for side effects
- many agents cannot cross blood brain barrier
- protein binding
- higher the protein binding the greater the potential for drug/drug interactions
elimination
- Renal
- dependent on kidney function, disease and age
- determine creatinine clearance
- hepatic
- dependent on disease and age
- drug interactions
- enzyme induction
- enzyme inhibition (drug slows down enzymes in the liver potential of toxicity
- half life
- the time it takes medication blood levels to drop in half
NOTE:
- reduce dose if person has kidney disease
- both renal and hepatic functions decrease therefore they both need less dose of drug
additive
two medications given together produce an effect equal to the sum of the effects of each agent
synergery
two medications given together produce an efect much greater than the sum of the effects of each agent
potentiation
two medications given together, but only one of the two agents possess the required action, but that action is enhanced by the second agent
agonist
an agent that stimulates a receptor
antagonist
an agent that blocks a receptor from being stimulated
factors influencing drug effects
- body weight
- surface area
- for example: cancer chemotherapy
- age
- sex (renal function)
- disease states
- genetics (metabolism)
- immunology (allergies)
side effects
unavoidable effect at proper dose
toxic effect
avoidable effect due to improper dose and drug/drug interactions
poison
harmful effect even in small amounts
adverse effect
unexpected effect, but may happen including allergies
allergies
- not dose related
- requires prior exposure
- reactions may be immediate to delayed for days
- reactions may be mild to life threaning (anaphylactic shock)
