QUIZ 1 - Basics Flashcards
(28 cards)
Why should OT students study pharmacology – 4 main reasons
- Understand patient’s responses to different drugs
- Determine ideal therapy schedule
- Learn to recognize drug therapy interactions
- Recognize adverse drug reactions and report them
What is Pharmacology?
-Study of how chemical substances affect living tissues
-How chemical agents bind to receptors to enhance or inhibit normal function
Define Pharmacotherapeutics and list 2 main areas
- use of agents to prevent, dx, and cure disease
- Pharmacodynamics: What the DRUG does to the BODY (mechanism of action)
- Pharmacokinetics: What the BODY does to the DRUG (ADME) (how fast)
What does ADME stand for?
A: Absorption (phase 1)
D: Distribution (phase 2)
M: Metabolism (phase 3)
E: Excretion (phase 4)
List the 2 primary routes of administration
Enteric
Parenteral (injection)
List the Enteral routes of administration
Oral
Rectal
Sublingual (under tongue, ie nitroglycerin)
Buccal (in cheek)
List the parenteral routes of administration
- IV
directly into vein - Subcutaneous
under skin to fat
faster than oral but slower then IM
rate is variable depending on the site
ex: insulin
heat, exercise, massage of the area will facilitate absorption
limb mobility or vasoconstriction from cooling will slow absorption. - Intramuscular
into skeletal muscle ie. flu shot - Epidural
into spinal column outside of dura - Intrathecal
delivered to cerebrospinal fluid (CSF) to get to CNS
What is Bioavailability?
- The fraction of a given drug that is actually absorbed into the body’s blood stream from the site of administration
- Example: Fosamax (1-10% oral bioavailability) used for osteoporosis: given on empty stomach 30 min before meal
What is Distribution?
- VD = volume of distribution
- Once a drug enters circulation it is then distributed throughout the body
- Total of drug concentration in body / plasma concentration
- If volume of drug is bound to plasma the VD will be small
- If the volume of drug is bound to tissue VD is large
- If a drug is highly bound to plasma proteins, not a lot of drug is available for response
- Only free drug is able to produce an effect
Potential problems of Distribution:
Blood brain barrier
Fat loving drugs
Hard for water soluble drugs to cross blood brain barrier
What is half life?
t ½
- The time it takes for ½ the drugs concentration to be eliminated from the body
- Most drugs are considered removed from the body in about 5 half lives
- If a drugs half life is 2 hours multiple that by 5 and then in approx. 10 hours it will be removed.
drug receptor interactions
Antagonistic or agonistic
Kefauver-Harris Amendment of 1962
Also known as the “Drug Efficacy Amendment”.
- Required drug manufacturers to provide proof of the effectiveness and safety of their drugs before approval .
- Required drug advertising to be more closely regulated and disclose accurate information about side effects
- Ex: Thalidomide: was prescribed to help with nausea and insomnia in pregnant women- caused a rare birth defect.
How long does drug development take?
List the phases
- based upon clinical studies and can take up to 12 years
- preclinical– tissue and animal testing ( 6 yrs)
- Phase 1 – safety assessment with small population.
- Phase 2- drug effectiveness study
- Phase 3 – double blind randomized control trials with other therapies
- Phase 4- post marketing surveillance Monitors for drug safety
What are orphan drugs
Drugs for rare diseases – companies are provided research grants and a streamlined approval process
Compassionate use
Drug naming and classification
- Chemical name – based on structure and compound
- Brand name – has a patent
- Generic name – the official name of the compound
- Ex. Brand name = Tylenol
Gen name = acetaminophen
Chemical name = N -acetyl-p- aminophenol - Rx should be written using generic name unless a specific brand is necessary
SCHEDULED DRUGS – CONTROLLED SUBSTANCES
Schedule 1
– most potential for abuse
– only avail for research ( LSD, HEROIN)
Schedule 2
– high potential for abuse
– no refills allowed (STIMULANTS, OPIOIDS)
Schedule 3
– lower abuse but can cause dependence
– 5 refills in 6 months ( TYLENOL WITH CODEINE)
Schedule 4
– lower abuse than above ( TRAMADOL)
Schedule 5
– lowest abuse potential ( LIQUID CODEINE)
ADVERSE DRUG EVENT:
- Anything that can go wrong when a person is administered a drug (including prescribing and administration compliance)
- Much more inclusive
- Major players: insulin, warfarin, digoxin
ADVERSE DRUG EVENT AND REACTION:
- serious effect of drug at therapeutic doses
- neg outcome that occurs while taking but does not imply the drug is the cause
WHY DO WE HAVE ADR’s
- most are an extension of what the drug is supposed to do
- drugs with narrow therapeutic window are responsible for most ADRs
- pediatric and geriatric pop
- polypharmacy (multiple meds among dif pharmacies)
- genetic variations in metabolism
organ dysfunction (liver, kidney)
CLINICAL ISSUES
drug admin wrong
wrong prescription
wrong dose
ADVERSE DRUG REACTIONS
- Every drug has a drug risk benefit ratio
- Types of adverse drug reactions (ADR)
- Drug/ drug reactions
- Drug/ food interactions
- Allergic reactions
- Doesn’t include human error in admin or patient compliance
- 1 in 10 admissions is due to ADR
OTHER SOURCES FOR ADRS
- sound alike drugs ( hydroxyzine, hyrdraalazine)
- use brand names vs generic names
- SALAD ( sound alike look alike drugs)
WHAT TO DO IF YOU SUSPECT AN ADR
- report to pts physician
- report to medwatch – tracks ADRs
- FDA decides what to do with that information such as adding it to label or withdraw it from the market
