Pharmacology '
what leads to an accumulation of some drugs that can cause severe adverse effects if dosage is not decreased
Severe renal disease
Drug
a substance that is taken to prevent, cure, or reduce symptoms of medical conditions and some taken for pleasure
DEA
charged with enforcing controlled substance act. Persons that handle controlled substances have to be registered with them, keep accurate records of transactions, and have secured storage
Drugs have several names including:
chemical, generic, and trade name
Trade name
designated and patented by the manufacturer. "Brand name".
pediatric dosages should be_______ _______ for accuracy
double checked; (make sure drug is safe for the tiny person)
Nurses should __________ clients about meds they are taking.
educate
FDA
enforces drug laws
Therapeutic range and therapeutic index
enough of drug to be beneficial but not enough to be toxic. ****this is the goal of drug therapy!!!
Schedule IV drugs
even less potential for abuse (benzos -lorazepam &diazepam, phenobarbitol, stadol, ambien
Liquids absorb _______ than tablets or capsules
faster
Malfeasance
giving the correct drug but by wrong route that results in death
Why are drug levels important?
if things aren't working right then there might be a higher level and may become toxic
Prototype drug
individual drugs that represent groups of drugs, one in which others in that class are compared to. Ex: "lols", "cillins", "statins"
Placebo
inert ingredients
Pharmacoeconomics
involves the costs of drug therapy. Includes cost of dispensing, storing, administering, monitoring, and losses due to expirations
Serum drug level (drug plasma concentration):
lab measurement of amount of drug in blood at a particular time. Reflects dosage, absorption, bioavailability, half-life, and rates of metabolism and excretion.
Nurses are ___________ for safe and accurate administration
legally resonsible
Schedule III drugs
lesser abuse potential than schedule II (anabolic steroids, ketamine, codeine preparations)
The receptor often described as a ______ into which drug molecules fit as a ______ and only those drugs able to bond chemically to the receptors in specific body tissue can produce pharmacologic effects.
lock; key
Safety
make sure they know how to store safely and how to give the medicine
Why is pharmacology important?
meds have an impact on healthcare, the nurse is the last person to catch an error before administration, you're responsible for understanding drugs, must understand drugs to know what the outcomes you should expect and what adverse reactions there could be
Meds with short half life require
more frequent dosing but depends on what med it is and why being given
Misfeasance
negligence- giving wrong dose or drug that results in death
Is there a perfect drug?
no, but strive to be the best: safe, lowest effective dose, fewest side effects, fewer doses a day, least amount of cost, fewer interactions with foods or other meds
Drug molecules must
occupy a minimal number of receptors to produce their effects.
Nonfeasance
omission- omitting a drug dose that results in death
When would you suspect a poisoning?
open pill bottle lying beside person, open bottle of cleaners, etc. Accidental poisoning common in young children. Try to determine what person has been exposed to (but not always possible to do this) and when exposure took place—this can help guide specific treatment after speaking with poison control!!!
Public health services
regulates vaccines and other biologic products
Generic name
related to the chemical name and is not related to the manufacturer. Often is indicative of its drug group (those ending in "cillin" are penicillins. Generic name typically in lower case letters. Only have 1 generic name
Trough
shows the lowest concentration of the drug. - Drawn just before next scheduled dose is given.
Pharmacology
study if drugs (chemicals)that alter functions of living organisms. Study of biological active compounds, how they react in the body and how the body reacts to them
What is the most important interventions concerning the use of meds?
teaching
Eliminate is determined by
the blood flow through the kidneys
Metabolites
the broken-down parts of the drugs that have been metabolized
What are the 2 basic classifications of drugs?
therapeutic and pharmacologic
Local effects
these act mainly at the site of application: impaled (inhaler, local in lungs), ointments, burn creams, etc
Serum half-life
time required for serum concentration to decrease by 50%.
Why do people take drugs?
to improve quality of life, stop progression of disease, prevent diseases
Agonist
triggers a response by binding to receptor cell and makes the same response as what normally occurs...."mimics"
Schedule V drugs
very low potential for abuse/dependence. Contain a moderate amount of controlled substance with another type of med. (lomotil, codeine cough syrup)
How does age of the child influence the absorption, distribution, metabolism, and excretion of medications?
very young have immature metabolisms, goes very slow and changes pharmacometrics
Pharmacodynamics
what the drug does to the body
Peak
when drug reaches the highest blood and plasma concentration - Drawn 30 minutes after IV administration and 1-2 hours (normally) after PO administration
passive immunity
when preformed antibodies are transferred from one person to another
Systematic effects
with this, medications are taken into the body and circulated through the bloodstream to their site of action and then eliminated from the body (PO- mouth, IV, etc.)
Why are drugs now derived in a lab?
you have more control over them but they aren't as effective but are more consistent in their effectiveness, there is also semi-synthetic like antibiotics
What affects how medications will work?
¨ Absorption ¨ Distribution ¨ Metabolism ¨ Excretion
Metabolism
¨ Biotransformation of the drugs; chemically converting a drug to a form that is usually more easily removed from the body. ¨ Liver is primary site of this process. (liver disease will affect the breakdown of drugs; slows down the drug)
Distribution
¨ Involves the transport of drug molecules within the body. • Depends greatly on adequate blood flow (heart, liver, kidneys -> key players in distribution) ¨ Protein binding important part of drug distribution. (meds need help from carrier protein; cross membranes and throughout parts they can't alone); two highly protein bound will fight each other ¨ ***only free or unbound parts of drugs can act on body cells. (protein bound drugs will not produce an effect)
How can drugs be administered?
¨ PO (mouth), IV (bloodstream), IM, SQ, inhalation (going directly where it needs to), topically, (sublingual is under tongue and absorbs quickly)
Absorption
¨ Process that occurs between the time a drug enters the body and the time it enters bloodstream to be circulated ¨ The rate and extent of absorption affected by: form(how its supplied; tablet, inhaled, etc.), route (oral, IV), GI function (elderly, pregnant have slower; someone with diarrhea has it going faster), blood flow, presence of food in GI tract, etc.
Excretion
¨ The elimination of drugs from the body. ¨ Most drugs are excreted by the kidneys and eliminated through urine.
Polypharmacy
¨ an increase of medication that they are taking and has higher risk of issues
Prodrugs
¨ cannot produce an effect until metabolized (ex. Benazapril (Lotensin), Enalapril (Vasotec))
Test for renal function
¨ creatinine clearance: normal 85-135 ml/min but does decrease with age
Toxic concentration
¨ excessive level at which toxicity can occur. Can be from single large dose, repeated small doses, or slow metabolism that allows drug to accumulate in body. Blood work is a good indicator but if exhibiting toxic signs then they should not have any more
CNS and blood brain barrier
¨ limits movement of drugs to brain tissue—have to have carrier or be lipid soluble to pass this barrier (protective mechanism); lipid is easier to transport but harder to excrete
1st pass effect
¨ meds are absorbed from the GI tract after going to the liver and are inactivated before they can produce an action (usually in oral drug, need to change routes)
Bioavailability
¨ portion of dose that reaches systemic circulation and is available to act on body cells (physiologic ability of drug to reach target cell and produce effect)
Efficacy
"how efficient", magnitude of response produced by drug
Potency
"how much need for a response", more potent drug produces effect at lower dose than others in that class
Pharmacologic
"how the drug acts/produces an effect in the body"
Therapeutic
"what is being treated by the medication"
Cultural practices
(herbal and homeopathic remedies)-these can inhibit or accelerate drug metabolism and their response
Factors that Affect Drug Action:
-Age -Weight -Gender -Environmental factors -Pathologic states(hypertension, kidney and liver issue, etc) -Psychological factors (believing med will work) -Disease state -time -drug tolerance
What are the nursing responsibilities regarding controlled substance?
-Must have Rx -Keep in a locked/ secured area -must be "signed out" -make sure "narcotic count" is correct -ensure patient actually takes med -"waste" needs to be verified and signed off by another RN
Drugs are classified according to:
-effects on particular body system -their therapeutic uses -chemical characteristics
How do attitudes and expectations influence the use of a placebo?
-has no active therapeutic effect but some believe it is working
What is a placebo?
-pill without working ingredients
Why do clients take medications?
-taken for acute and chronic health conditions -acute: pain and infection are treated with drugs that provide immediate relief -chronic: problems such as HTN, DM, HIV require meds over an extended period of time (long term therapy) to move signs and symptoms and help slow the progression of the disease
How can nurses help prevent noncompliance?
Educate pt at every encounter to inc. compliance, build trusting relationships
Why are nurse Practice Acts important?
Every state has its own laws regarding drug administration by nurses. Nurses are held accountable to these standards
Who is at risk for being noncompliant?
Everyone....especially illiterate, elderly, poor
What do we need to teach the client?
General info about the med, why is was Rx for them, how and when to take it, side effects, intended effects, and safety measures related to it (cause dizziness, make sleepy, etc./need to check blood sugar before, check HR before or BP, etc.)
loading dose
Given to get drug into body quickly, larger than normal dose
Maintenance dose
Given to maintain the drug level after loading dose
Schedule II drugs
High potential for abuse and dependence -MUST have WRITTEN Rx signed by HCP -NO refills or telephone orders (codeine, morphine, demerol, methadone, oxycodone)
Barriers to adequate healthcare for culturally diverse patients:
Language, poverty, access, beliefs, etc
How can you make sure that what you have taught has been understood?
Return demonstrations, have them read back instructions to you, ask them questions about what has been taught, watch their body language for cues that not understanding the info, ask them questions about what have been discussing.
Meds are usually given for their:
Local and systematic effects
What are hindrances to compliance and learning>
Might be language barrier, might not be able to hear, might not be able to see/see well, ability to read, ability to afford medications, no way to get Rx from pharmacy, might not be able to open the bottles, etc
What are the nurse practice acts?
Misfeasance, nonfeasance, malfeasance
Schedule I drugs
NOT approved for medical use (LSD, Heroine, Marijuana)
Chemical name
a drug only has 1 of these names ex: calcium gluconate, sodium chloride
Goal of treatment for poisons?
Suspect when toxicity is present and begin treatment Start treatment ASAP after ingestion, supporting and stabilizing vital functions, preventing further damage by reducing and absorption or increasing elimination, and administering specific antidotes if indicated
Where do drugs come from?
Were historically derived from plants, animals, and minerals. Now, most are synthetic compounds that are manufactured in labs
Pharmacokinetics
What the body does to the drug (med) (how the body handles the drug)
Polypharmacy
administration of many drugs together. The higher the # taken—the higher the risk for interactions and adverse effects
Minimum effective concentration (MEC):
amount of drug that must be present before drug can exert its therapeutic effect (desired effect)
Pharmacotherapy
application of drugs for the purposes of disease preventions and treatment of suffering
Federal trade commission
can suppress misleading advertisements of nonprescription drugs
Developmental considerations:
can they follow directions, how to get it in them, band aid on baby doll, etc
Antagonist
blocks an action; binds to receptor and blocks normal action that would occur or changes the pharmacokinetics. Ex: opioid antagonized by Narcan
How can accidental poisonings be prevented?
› Keep things out of reach!!!
Examples of varying responses of different drug classifications on cultural groups:
›Antihypertensives (African Americans do better when they have a combo of meds for BP) ›Antipsychotics and antianxiety meds (Hispanic and Asian pop. Do better with lower dose)
How does aging affect drug therapy?
›CNS changes ›Liver doesn't function as well ›Decreased GI secretions and motility ›Decreased cardiac output ›Decreased blood flow to liver and kidneys
What are the effects of poisons?
›Results from excessive amounts of a drug and may cause reversible or irreversible damage to body tissues.
Signs and symptoms that may be seen for poisons
›abdominal cramping, N/V/D, loss of consciousness, open container close by
active immunity
›body produces its own antibodies in response to exposure