Definition of Pharmacotherapeutics
area of pharmacology that refers to the use of specific drugs to prevent, treat, or diagnose a disease
Definition of Pharmacokinetics
the study of how the body deals with the drug in terms of the way it is absorbed, distributed, and eliminated
Definition of Pharmacodynamics
the analysis of what the drug does to the body, including the mechanism by which the drug exerts its effect
Definition of Pharmacogenetics
the branch of pharmacology concerned with the effect of genetic factors on reactions to drugs.
What is the difference between a chemical name and a generic name?
- Chemical name refers to specific compound's structure (typically long and cumbersome)
- Generic name tends to be shorter and often derived from chemical name.
Two alternative ways the generic name can be thought of
List of steps for having a drug approved
- Animal studies
- Human Clinical Trials phase I
- Human Clinical Trials phase II
- Human Clinical Trials phase III
What is bioequivalence?
If 2 products are said to be bioequivalent it means that they would be expected to be, for all intents and purposes, the same.
*This does not always occur and sometimes people react differently to a generic drug compared to brand name drug.
When referring to a medication, what is the ideal drug name to use?
Brand (or Trade) names can often be confusing and sound like other drugs used for very different purposes
Something to ask or check if patient complains of not feeling quite right or having increased side effects to their medication
Did they change their medication from brand name to generic.
What does Human Clinical Trials Phase I typically involve?
Usually a small group of healthy volunteers (20-80 people)
What does Human Clinical Trials Phase II typically involve?
Usually a small group of people with the targeted pathology (200-300 people)
What does Human Clinical Trials Phase III typically involve?
Usually a much larger group of people with the targeted pathology (several hundred - several thousand people)
Common drug that gets expedited through the drug approval process
What is postmarketing Surveillance?
drug is monitored for side effects after released.
If substantial or severe adverse effects reported, drug can be pulled off the market
What is a black box warning?
- strictest warning in the labeling of prescription drugs by FDA
- when there is reasonable evidence of an association of a serious hazard with the drug.
EX: Clindamycin- antibiotic that flushes out all of intestinal flora
What is an orphan drug?
- a drug that remains commercially undeveloped owing to limited potential for profitability.
- Usually under 200,00 people in the US with that disease.
- Because there is limited demand, FDA will fund production of orphan drug.
Off label medication?
approved medications used for something other than their intended indications.
Ex; Neurotin- anti-seizure medication also used to treat pain and has been used as an anti-psychotic
Who assumes liability for off label medication?
benefits and disadvantages of OTC meds
- Do not need to see a doctor to get them
- safety is reasonable- typically reduced in half to accommodate for consumer error
- clinical effectiveness proven dosage
- Dr. not there to tell consumer how to use them
- insurance typically does not pay for OTC meds leading to potentially more out of pocket cost
Why would a physician need a DEA license?
Augments prescription writing privileges to include schedled medications.
What are schedule I drugs?
drugs with highest potential for abuse and not used for therapeutic use
Ex: LSD, heroin
What are schedule II drugs?
drugs approved for specific therapeutic purposes but still have high potential for abuse and addiction
Ex: morphine, fentanyl
What are schedule III drugs?
drugs have mild to moderate risk for physical and/or psychological dependence
Ex: anabolic steroids, codeine
What are schedule IV drugs?
drugs supposedly have lower potential for abuse and dependence
What are schedule V drugs?
drugs with lowest risk for dependence and abuse
Ex: some cough medications, antidiarrheal preparations
What is a dose-response curve?
provides info about the dosage range over which the drug is effective, as well as the peak response that can be expected from that drug.
What is the threshold dose and where is it located on the dose-response curve?
- min dose of drug that will produce a detectable degree of any given effect
- At the very beginning of the curve
What is the ceiling effect and where is it located on the dose-response curve?
- point at which there is no further increase in the response to a drug- maximal efficacy of drug is reached.
- located at highest point and end point of dose-response curve.
What is the median effective dose?
a dose that produces the desired effect in 50% of a population.
What is the median toxic dose?
dose at which 50% of population exhibits adverse effects important
Ex: used when prescribing cancer medication and balancing out hurt vs harm to cells.
What is the peak level?
highest serum level of drug in a pt based on a dosing schedule
What is potency of a drug?
related to the dose that produces a given response in a specific amplitude refers to the fact that less of the compound is required to produce a given response.
What is meant by the efficacy of a drug?
the capacity for beneficial change (or therapeutic effect) of a given medication
What is affinity and why do I care?
- Dr. Thompson clarified in her email that affinity played a role how agonists and antagonists work.
- The definition in chemistry is the tendency of two substances to form strong or weak chemical bonds forming molecules or complexes.
What is therapeutic index?
- index calculates therapeutic effect
- provides a measure of drug safety
- formula is median toxic dose (TD) divided by the median effective dose (ED)
Is it better to have a lower therapeutic index?
The lower the index, typically the riskier the drug
Two primary routes of for drug administration
The "sub" routes of enteral administration
- sublingual (under tongue)
- buccal (between cheek and gums)
The "sub" routes of parenteral administration
- intraveneous injection
- intra-arterial injection
- subcutaneous injection
- intramuscular injection
- intrathecal injection (spinal-subarachnoid space)
- transdermal (incldes iontophoresis)
True or false: a drug may not be approved until it is tested on the general public
FDA approves after 3rd phase of human clinical trials are successfully completed
True or False: Expedited review takes 7-9 years
That is how long a normal review typically takes
True or False: Practitioners need to get special permission to use off-label
Hwever, they are assuming the risk
What is the risk of taking a generic drug?
What 2 factors predict the therapeutic effect?
- therapeutic index
- type of drug
What 2 organs play a major role in medication administered orally and why?
- liver- has first pass effect in which much of the drug is metabolized
- kidneys- she didn't explain this, but I wonder if it's because the kidneys clean the blood?
How does medication enter liver?
through portal vein
Why is medication not just given sublingual or buccal to avoid the negative impact of the liver and kidneys?
Some medication molecules are too large and cannot be effectively absorbed through those tissues
Advantages and disadvantages of oral medication adminstration
- limited or erractic absorption of some drugs
- chance of first pass inactivation in liver
Examples of oral medications
analgesics like advil, sedative-hypnotics such as Xanax, ect...
Advantages (2), disadvantages (1), and an example of sublingual adminstration medication
- rapid onset
- not subject to the first pass inactvation
- drugs must be easily absorbed by oral mucosa
Advantages (2), disadvantages (2), and an example of rectal adminstration medication
- alternative to oral route
- local effect on local tissues
- poor or incomplete absorption
- chance of rectal irritation
Example: laxitives and other suppositories
Advantages (3), disadvantages (2), and example of inhalation adminstration medication
- rapid onset
- direct application for respiratory disorders
- large surface area for systemic absorption
- chance for tissue irriation
- patient complaince sometimes a problem
Example: general anesthetics suh as nitrous oxide, anti-asthmatic agents
Advantages (2), disadvantages (1), and an example of injection adminstration medication
- provides more direct administration to target tissues
- rapid onset
- chance of infection if sterility is not maintained
Example: insulin, antibiotics, anti-cancer drugs such as depo-provera, and narcotic analgesics such as morphine
Advantages (1), disadvantages (1), and an example of topical adminstration medication
- local effects on surface of skin
- only effective in treating outer layers of skin
Example: antibiotic ointments, antifungal creams such as lotramin
Advantages (2), disadvantages (1), and an example of transdermal adminstration medication
- introducing drug into body without breaking the skin
- can provide steady, prolonged delivery via medicated patch
- drug must be able to pass through dermal layers intact
Example: nitroglycerin, motion sickness medications , drugs used with phonophoresis and iontophoresis
What is bioavailibility?
The extent to which the drug reaches the systemic circulation
Ex: 100 mg of Drug X is taken orally, but only 50 mg of Drug X makes it into systemic circulation
What is something that can go wrong with bioavailiblity of a drug?
It can build up in the system and there are higher levels of the drug than desired in systemic circulation
What type of tissue do drug tend to be stored in and and why?
Due to low blood circulation and metabolic rate
A second location where drugs can be stored
Drugs can bind to receptors and stick around in bone matrix .
Examples given in class were lead and tetracyclines doing this very thing. Tetracycline can build up in teeth andyellow them
Advantages of time release controlled medications
- lower (potency usually) and slower
- provide therapeutic sustained levels
- Ex: anti-parkinson meds
What are pro-drugs?
pharmacologically inactive medications that are metabolized into an active form within the body. Instead of administering a drug directly, a prodrug might be used instead to improve how a medicine is absorbed, distributed, metabolized, and excreted
Ex: fecal implant to restore natural flora in gut
What is biotransformation?
chemical changes that take place in the drug following administration.
What is clearance of a drug?
- organ's and tissue's ability to eliminate the drug (systemic clearance)
- single organ or tissue's ability to eliminate a drug
What is the half-life of a drug and why does it matter?
- the amount of time required for 50% of the drug remaining in the body to be eliminated
- important in describing the duration of activity of the compound
- factors into how well a drug will metabolize down to zero and how it will behave.
Factors (7) that may affect drug metabolism when considering prescribing drugs for an individual
- genetics- ex: prescence or absence of enzymes in a person's genetic make-up
- Disease- ex: structural and funcational damage to organs
- Drug Interactions- ex: what medications is the person taking and what type of interactions will the medications have
- Age- ex: medications can affect elderly and young very different than a normal healthy adult
- Diet- ex: a person's diet can affet how a drug is absorbed and metabolized
- Sex- ex: Men and women have different hormones and this can affect how drugs are metabolized
- Other- ex: occupational hazzards/exposure, weight, smoking, ect...
What is affinity?
the mutual attraction between a drug and a specific cellular receptor
What is an agonist?
- a drug that binds to a receptor and causes some change in cell function
- an agonist has affinity and efficacy
What is an antagonist?
- block an action
- also have affinity
- not considered to have efficacy
- Thompson described as attaching to cell and play defense by blocking agonist
- used beta-blockers as an example
Competitive vs. Noncompetitive antagonist
- has equal opportunity to compete for receptor as the agonist
- whichever concentration of the competitive antagonist or agonist is higher wins the receptor battle
- form strong and essentially permanent bonds to the receptor.
- have strong affinity for receptor or actually form irreversible covalent bonds to reeptor
What is a mixed agonist- antagonist?
Medication has both agonist and antagonist properties
Ex: Tamoxifin- given to women after surgery for a breast cancer. Acts as antagonist because it blocks the effect of estrogen on breast tissue from developing new tumors. Acts as an agonist to stimulate estrogen receptors on bone to prevent osteoporosis.
What is a partial agonist?
- does not evoke max response compared to strong agonist
- may have high affinity, but low efficacy (due to piss poor attempt at activating receptor)
What is an inverse agonist?
binds to receptor as a normal agonist, but has the exact opposite reaction as a normal agonist (unlike an antagonist which would just block what the normal agonist was trying to do)
aka:the story of MaryBeth's life