Basic Principles of Pharmacology and Therapeutics
Naloxone example for agonist and antagonist Naloxone is given for Heroin/ morphine overdose. Why? What is the agonist, and what is the antagonist?
Naloxone goes into the narcotic receptors instead of heroine and doesn't do anything "these drugs pick the lock" The AGONIST will be heroine/ morphine opiate b/c it stimulates a reaction and your body responds to the drug The ANTAGONIST will be Naloxone because they attach to the receptors but doesn't cause a response
We measure the "toxicity" of a drug by measuring its _________________ _____________________
Therapeutic index (wiggle room)
Which drugs have a narrow therapeutic index
digoxin, Lithium, warfarin
Orphan Drug >200,000 Americans
has potential use in only a small number of people w/ rare conditions "non-profitable" FDA to provide incentives, e.g., tax breaks, to the company to research, develop and market the drug for a small number of patients
Would safer drugs have a higher therapeutic index or a lower therapeutic index
higher= safer (wider margin) lower= more dangerous (more narrow)
Prescription drugs account for about _______ of overall U.S. health care expenditures
11%
Drug
"an article (other than food) intended to AFFECT the structure or any function of the body." Clinically it is defined as any substance used in the diagnosis, treatment, cure or prevention of disease or a condition.
Cost also has a placebo affect. How?
$5 pain pill works better than .50 cent pain pill!!! Subconscious thought
How to initiate therapeutic drug monitoring
1. Obtain blood after you have steady serum (~ 5 half-lives) 2. Obtain trough blood concentrations for most drugs (lowest point at which drug has an effect) You do this b/c if the patient has therapeutic trough levels, he or she surely has therapeutic peak levels of that specific drug 3. For some narrow therapeutic index (NTI) drugs, you may need to obtain both peak and trough levels to monitor for adverse effects.
Non-Adherence with Prescriptions- why?
1. forgot to take a prescribed medication 2. not filled a prescription they were given 3. took less than the recommended dosage or substituted an OTC medication.
IMS Health: Drug Spending to Jump 30% to $_______ in 2020
1.3 trillion
The cost of Rx drugs has decreased the past 5 years, but are expected to increases approximately ___________ in 2014.
3-5%
America ranks _______ out of 191 when it comes to overall health status
37
In the U.S., about ______ of prescriptions dispensed in 2020 will be for generic medicines
90%
______________ of Prescriptions Not Filled
> 30%
Pharmacokinetics
ACTION: the study of drug absorption, distribution, special tissue binding or affinity, metabolism and excretion (ADME).
Action
How it works of drug is defined as the chemical changes or effects a drug has on body cells. These changes or effects may be reversible or irreversible.
Therapeutic Index calculation
LD50/ED50 orTD50/ED50 Lethal dose/ Effective Toxic/ Effective a measure of the margin of safety.
Why did some of the patients say thy had relief from the saline injections?
Subconsciously, the body produces endogenous endorphins or "natural morphine."
_______________ (or Legend) drugs are drugs requiring a prescription to be dispensed. These are designated as Rx on the label.
Prescription (or Legend)
Biological variation is a fact of life. (Bell-shaped curve of normal distribution)
Some people respond to drugs at lower OR higher concentrations 95% of people fall within 1-2 standard deviations ex: 25 mg of a drug- most people will get that!
Polymorphisms
Tiny discrepancies in our genome (10 million points in which our individuals codes can vary)
__________ is a measure of the difference between (therapeutic index) the lethal dose in 50% of the tested population (LD50) or the toxic dose (TD50) and the effective dose in 50% of the tested population (ED50).
Toxicity
Idiosyncratic effect/ reaction
When a person does not fall in the common std. deviation for a drug Negative reaction occurs rarely and unpredictably-- we don't know what happened!
Human Genome Project
a 13-year effort coordinated by the US Department of Energy and the NIH People are now having their genomes analyzed early in life to reveal their risks. Then, armed with that information, we can tailor medicines to individual needs.
A drug that has a chemical affinity and intrinsic activity for a receptor site and reacts in such a way to initiate a specific action is called an ____________
agonist
If the drug has affinity for the receptor, but does not illicit an effect, it is called an ______________
antagonist (attaches to receptor but doesn't activate it)
Behind-the-counter (BTC) drugs
are restricted to pharmacy-only sales, but do not require a prescription. Examples of BTC drugs include pseudoephedrine and hormonal contraceptives.
only ____________ _______________ have a patent protected for being able to be sampled. Once they go generic, they CANNOT not sampled
branded drugs
Therapeutic index can be found using a ____________ _____________ ________________
dose response curve
the most expensive drug in the U.S. is ___________ indicated as a therapy for the life-threatening blood disorder paroxysmal nocturnal hemoglobinuria
eculizumab (Soliris®)
Nonappearance to prescription drugs are highest with
expensive drugs and chronic preventive therapies
This increase in spending will be driven by: (3) things
expensive new drugs aging populations increased generic drug use in developing countries.
Drug Samples: A Good or Bad Idea?
good: "test" the drug to see if they can tolerate it without receiving a full prescription (saves $) bad: starting pt. on an expensive branded sample, adds to to the overall cost long-term. bad: samples by-passes the pharmacist's final check for accuracy and counseling.
*Potency
how much of a drug is required to illicit a pharmacological effect. A drug might be more potent, but we give them in lesser doesn't mean they are more effective or better...we just use less of it
Indication
is an illness or disorder for which a specific drug has documented usefulness. ex: rheumatoid arthritis, IBD, and cirrhosis (some drugs are used for all of these diseases
Pharmacodynamics
is defined as the study of drug interactions within body tissue and how these effects are produced.
Chronotherapeutics ex: heart attacks (mornings), Asthma and GI bleeds (1-2 in the morning), diabetes, statins (w/ evening meals b/c most cholesterol is synthesized at night
is the delivery of medications in varying amounts during the 24-hour day takes into consideration the day-night patterns in the risk of disease or exacerbation of symptoms as well as biological rhythm-dependent differences in patient tolerance to them. For example, most acid is secreted in the evening, give H-2 antagonists, e.g., Tagamet, Pepcid for ulcer disease at bedtime. Low-dose aspirin should be given at bedtime for optimum ant-platelet effects.
Pharmacogenetics
is the study of variability in drug response and toxicity due to genetic factors.
Contraindication
is when the drug should not be used in a particular illness or disorder.
Explain the placebo effect/ power of suggestion
morphine vs. saline injections you have 2 groups, both that are experiencing pain 1. Group 1: Morphine given for pain (~3 hours long). After some hours, you give naloxone (blocks effect of morphine)- pt has pain 2. Group 2: Saline given for pain. Some say they have relief. After some hours, you give naloxone. Pt feels pain
Evidence-Based Practice (EBP) or Evidence-Based Medicine (EBM)
practical decisions made should 1) be based on research studies 2) that these research studies are selected and interpreted according to some specific norms characteristic for EBP
300, 400, 600, 800 mg of Ibuprofen is ___________________
prescription
Pharmacogenomics
takes the information gained by pharmacogenetics and applies it to the development and use of medications. This is sometimes called "Precision Medicine."
Pharmacology
the STUDY of actions and effects of drugs within a living system. These include "legal" drugs such as antibiotics, "illegal" drugs such as heroin, and prescription and non-prescription drugs. Alcohol, nicotine and caffeine are also recognized as drugs.
Efficacy
the actual effect and how well it accomplishes it. Being more "potent" does not necessarily mean that a drug is more efficacious. For example, Bumex® is said to be 20 times more potent than Lasix®; but both have equal efficacy if given as 2 mg of Bumex® and 40 mg of Lasix®.
Measurement of serum or plasma levels of drugs to assess treatment response and to avoid adverse effects is known as
therapeutic drug monitoring (TDM).
Suggestions for Consumers to Save on Drug Costs
• Lifestyle changes first, meds second (toughest prescription you will write- people don't want to change) • Newer isn't always better. • Make use of your insurance plan and know your plan's formulary • Use generic meds