Pharm 6 Flashcards
which drugs are poison
all - they all have the potential to produce harmful and beneficial effects
new drugs are gotten from
natural sources or synthesized
sequence of drug development
discovery/characterization of drug, experimental animal studies, IND application, Clinical studies (phase I, II, III), submission of NDA, approval of NDA, post marketing surveillance (Phase IV)
types of studies
animal studies and clinical trials
experimental animal studies (pre-clinical) ascertain
beneficial/harmful effects on vital organs,
elucidate the mechanism of action,
determine the pharmacokinetics
Animal toxicity testing
tests for teratogenicity, mutagenicity, carcinogenicity:
acute,
subacute,
chronic
acute toxicity
single does, to calculate TI (LD50/ED50)
subacute toxicity
3 doses, 4weeks to 3 months
chronic toxicity
6 months
investigational new drug application (IND)
an application for investigational new drug (IND) must have been approved by the FDA before the drug can be distrubuted for conducting clinical studies in human subjects
Clinical trials
once IND is approved by FDA, testing on humans canbe divided into 3 phases before approval of general marketing of the new drug for the prescription use
4th phase of study follws
NDA approval - phase 4 is a surveillance/observation of patients taking these drugs and monitor adverse effects
volunteers of clinical trials must give
written infomrmed concent (from patients or legal guardians of patients)
clinical trials should be conducted in conformity with
helsinki declaration
Phase I consists of
carful evaluation of safety in a small number of healthy volunteers (25-50)
phase 1 determines
whether humans and animals show significantly different responses to the durgs
phase 1 establishes
the probable limits of the safe clinical dosage range
Phase 1 can be conducted
nonblind or open (both investigator and subjects know what drug is administered)
Phase 1 often measures
pharmokinetics - absorption, half-life, and metabolism
Phase 2 involves
evaluation of a drug in a moderate number of patients ( approx. 200) with the target disease
Phase 2 types of studies
single or double blind with an inert substance (placebo) or an older active drug (positive control) in addition to the investigational agent
Phase 2 goal
to determine the desired therapeutic effect at the doses that are tolerated by the patients
Phase 3 consists of
large design involving many pateins ( approx. 5000)
Phase 3 study incudes
placebo or positive controls in double blind corssover design
Phase 3 goal
compare efficacy and safety with older drugs, explore spectrum of beneficial effets of new drug and to discover toxicity
NDA (new drug application) approval occurs
when phase 3 meets expectation of the FDA to market the new agent
NDA contains
hundred volumes of reports of all preclinical and clinical data pertaining to the durg under review
How long does FDA review
may take 3yrs or longer,
may be greatly accelerated if there is an urgent need (cancer, chemotherapy, AIDS)
Phase 4
post marketing surveillance
Phase 4 is done to
monitor safetly in pateint population and represents the phase of evaluation in which the toxicities that occur very infrequently are detected and reported to prevent major disaster
Phase 4 and FDA
phase 4 is not regulated by the FDA
Orphan drug
when a drug is not developed into a usable medicine form bc the developer will not recover the costs (disease - orphan disease, sufferer - health orphan)
orphan drug is for
a rare disease affecting fewer than 1/200,000 people
free-market economy is liable to leave
untreated rare diseases eg. Some cancers (in all countries), some common diseases eg. Parasitic infections (in poor countries)
current legislation provides
regulatory incentives encouraging the development of orphan drugs,
eg Digibind for digoxin toxicity
prescription
written order for compunding, dispensing, and administering drugs to a patent and once signed by a physician it becomes a legal document
rational prescribing
define the patient’s problem (make a specific diagnosis),
consider the pathophysiology of the diagnosis selected,
select a specific therapeutic objective (what do you want to achieve with the treatment),
select a drug of choice (p-drug/P-treatment),
determine the appropriate dosing regimen,
give information instructions and warnings (very importnat and often neglected),
montior the treatment
P-drug (P-treatment) (Pre)
select a drug of choice on the bases of a comparison of their efficacy, safety, suitability, and cost
Essential medicines
drugs that satisfy the health care needs of the majority of the population –they should be available at all times in adequate amounts and in appropriate dosage forms at a price the community can afford
WHO list of essential medicines
contains a core list and a complementary list
core list
presents a list of minimum medicine needs for a basic health care system, listing the most efficacious, safe and cost-effective medicines for priority conditions
(priority conditions are selected on the basis of current and estimated future public health relevance, and potential for safe and cost-effective treatment)
complementary list
presents essential medicines for priority diseases, for which specialized diagnostic monitoring facilites are needed
since 1977 to 2002 the number of complementary list durgs has
doubled form 186 to 320
Prescription consists of
superscription, inscription (body), subscription, signa
superscription
it consists of heading and where there is symbol Rx (meaning to take Rx comes before the inscription)
Inscription
the body of the prescription and provides the name and quantities of the chief ingredients of the prescription. Also the does and dosage form included
subscription
consists of specific instructions to the pharmacists on how to compound the medication expressed in latin or english (but tyr and avoid latin)
all prescriptions should contain
prescribers full name adress telepohone number, patients full name address age and sex, date of issuance, drug name dosage form and dose, directions for use, refil instructions, signature of prescriber
compliance
the extent to which a person’s behavior in terms of taking medications, following diets, or executing lefestyle changes coincides with medical or health advice - compliant when they do what dr recommends, this view considers the patient as a passive actor abiding by instructions and directions pronounced by prescribers
what is the contorvery against compliance
the term fails to respect the idea of patient autonomy suggesting that doctor knows best and follow the doctor’s orders
adherance
the term has been regarded as more respectful of the role the patient can play in his or her own treatment suggesting that the doctor is engaged in reasonable negotiations with the patient rather than in the perfunctory issueing of instructions (RPSGB)
concordance
shared decision making and arriving at an agreement that respects the wishes and beliefs of the patient,
aim is to optimize health gain from the best use of medicines,
compatible with what patient desire and is capable of chieving
concordance is intended to convey
respect for the health beliefs of both doctor and patient and specifies that medicine taking should be the result of a mutually arrived agreement between aptient and doctor and not the result of the patient’s more or less reluctant compliance with orders issued by the doctor as per tradition
Doctor compliance
extent to which the behavior of doctors fulfils their professional duty: not to be ignorant,
adopt new advances when they are sufficiently proved,
prescribe accurately,
tell patients what they need to know,
warn
FDA recognized 2 types of durgs
over the counter durgs,
prescription durgs/legend drugs
comprehensive drug abuse prevention and control act
also called controlled substances act - CSA classified drugs into five schedules based on their potential for abuse and clinical usage
Schedule I drugs
high abuse potential and no legitimate medical use,
distribution and possession prohibited,
lack of accepted safety for use of the drug or other substance under medical supervision
Schedule I drugs ex
Heronin,
lysergic acid diethylamide (LSD)
Schedule II drugs
high abuse potential but have a legitimate medical use,
distribution is highly controlled through restrictions on prescriptions,
abuse of the drug may lead to severe psychological or physical dependance
Schedule II ex
morphine and methadone
Schedule III durgs
less potential for abuse than the drugs or other substances in schedules I and II,
abuse of the drug may lead to moderate or low physical dependence or phsychological dependence
Schedule III drugs ex
anabolic steroids,
codeine,
buprenorphine
Schedule IV drugs
low potential for abuse,
abuse may lead to limited physical dependence or psychological dependence
Schedule IV drugs
propoxyphene,
pentazocine,
diazepam,
alprazolam
Schedule V durgs
low potential for abuse relative to the drugs or other substances in Schedule IV,
abuse of the drug or other substances may lead to limited physical dependence or psychological dependence
Schedule V ex
diphenoxylate,
Pregabalin
schedule II can’t be
refilled,
prescscription may not be transmitted on phone
III-V can be refilled but
for max 5 times and no case after 6 months from the date of prescription
Teratogenic drug classes
A B C D X
A
Preg animals:No teratogenocity
Preg Humans:No teratogenocity
Ex: Folic acid
B
Preg animals: May be teratogenic
Preg Humans: No teratogenocity
Ex:Zidovudine
C
Preg animals: May be teratogenic
Preg Humans:No studies
Ex: Asprin
D
Preg animals: Teratogenic
Preg Humans: May be Teratogenic
Ex: Phenytoin, Benefit outweigh risk
X
Preg animals:Teratogenic
Preg Humans: Teratogenic
Ex: Thalidomide, PG , Risk outweigh Benefit
Pharmacoepidemiology
study of the use of effects of drugs in large number of people proficing further insight into the efficacy, and especially the safety of new drugs once they have passed from limited exposure in controlled therapeutic pre-registration trials to the looser conditions of their use in the community
Pharmacoeconomics
identifies measures and compares the costs and consequences of durg therapy to healthcare systems and society.
healthcare costs can be categorized as
direct medical,
direct nonmedical,
indirect nonmedical,
opportunity
