Fundamentals Flashcards
1
Q
What is pharmacology?
What is a drug?
What is pharmacotherapy?
A
Pharmacology - the study of how drugs work in the body
Drug - any substance that is taken to prevent, cure or improve symptoms of a medical condition
Pharmacotherapy - use of drugs for disease prevention and treatment of suffering
2
Q
CLASSIFICATION OF DRUGS
Therapeutic
Pharmacologic
A
Therapeutic -
- describes what condition is being treated by the drug
- decease specific
- prefix “anti” generally refers to therapeutic classification
- drugs may be placed in several therapeutic categories
Pharmacologic -
- describes how the drug acts in the body or “mechanism of action”
May use a drugs chemical name
3
Q
DRUG NAME TYPES
Chemical
Trade
Generic
A
Chemical
- name assigned according to chemical structure
Trade
- brand name for a drug that is selected by the company that develops it and hold the patent
- always capitalized
Generic
- contains the same ingredients as a trade drug and mush do the same thing
- may differ in color, shape, and taste from trade drug
- are not capitalized
- cost is cheaper
4
Q
DOSING INTERVALS
Schedules
STAT
PRN
A
Schedules - regularly ordered
STAT - a medication that is needed immediately, usually in a life threatening situation
PRN - administered as needed by the patients condition
5
Q
WHAT ARE DRUG ADMINISTRATION ROUTES?
A
- Enteral - gastrointestinal(orally), nasogastric (NG), or gastrostomy tube (GT)
- Sublingual
- Topical
- Ophthalmic
- Otic
- Intranasal
- Rectal
6
Q
WHAT IS PARENTERAL?
A
- Parenteral- dispensing of medications via needle into:
- Skin layers – intradermal (ID)
- subcutaneous tissue (SQ)
- Muscle- intramuscular (IM)
- Veins- intravenous (IV)
7
Q
WHAT IS PHARMACOKINETICS AND ITS 4 PROCESSES?
A
- Pharmacokinetics- study of drug movement throughout the body or what the body does to drugs after they are administered.
- 4 Processes:
- Absorption- Stomach and Intestines (GI tract)
- Distribution- Bloodstream
- Metabolism- Liver
- Excretion- Kidneys
8
Q
HOW DO DRUGS RACH THEIR TARGET CELLS?
A
- Drugs use diffusion and active transport to cross membranes to reach the cells.
- Diffusion- is the movement of a chemical from an area of higher concentration to an area of lower concentration.
- Example- perfume
- Example- Pool
- Active transport- some drugs cross membranes against the gradient from a low concentration to a higher concentration. Requires expenditure of energy on the part of the cell and carrier protein. These carriers are also called pumps.
- Example- person pushing a wheelbarrow up a hill
9
Q
WHAT DRUCH WILL AND WILL NOT PASS ACROSS MEMBRANES?
A
More likely to cross:
- -Small drugs
- -Non-ionized drugs
- -Lipophilic
Less likely to cross:
•-Hydrophilic
•-Large drugs
•-Ionized drugs
10
Q
WHAT ARE THE SITES OF ABSORPTION AND WHY DOES THIS HAPPEN?
A
Key- medications must be absorbed into the body from the site of administration to the bloodstream in order to have their intended action
•Sites of Absorption:
•Mouth- SL tablets, buccal
•Stomach/intestine - oral medications may be absorbed in the stomach but many are absorbed in the duodenum
•Dermal- patches
•Inhaled- intranasal
•Rectal/vaginal- suppositories, or vaginal creams
•Intramuscular/subcutaneous- directly from these layers into bloodstream
•Intravenous- directly from veins into bloodstream
11
Q
WHAT TYPED OF MEDICATION WILL ABSORB FASTER OR SLOWER?
A
FASTEST TO SLOWEST
- liquids, elixirs, and syrups
- suspension solution
- powders
- capsules
- tablets
- coated tablets
- enteric-coated tablets
12
Q
WHAT IS ABSORPTION AND WHAT FACTORS INFLUENCE IT?
A
- Dose form- extended release or enteric coated medications designed to be released more slowly
- Food- some medications require food to be absorbed, and others are required to be taken on an empty stomach
- pH- some medications require an acidic environment like the stomach or a more basic one like the intestine to have maximal absorption
- Drug interactions- minerals (calcium, magnesium, iron) hinder, fat
- Surface area- lungs or intestine
- Disease states- Crohn’s disease and accompanying malabsorption, diarrhea
- Absorption- primary pharmacokinetic factor that influences the onset of drug action, i.e., length of time it takes for a drug to produce its effect
13
Q
WHAT IS DISTRIBUTION AND WHAT ARE SOME FACTORS OF IT?
A
- Phase of movement of the drug once it is absorbed.
- Drugs interact with blood components and may be physically and chemically changed before they reach their targets
- Tissues with the greatest blood flow receive the drug first
- examples-
- Solubility- some drugs are water soluble and some are fat soluble
- Tissue storage– some drugs have a higher affinity for muscles, while others are lipophilic
- Drug-protein binding- many drugs bind to protein such as albumin and this complex is too large to cross capillary membranes and be distributed; trapped until release.
- *unbound or free drug is the one that has ability to exert its action
14
Q
WHAT IS METABOLISM?
A
- Metabolism is the process by what your body converts what you eat and drink into energy
- Also called “biotransformation.”
- Involves multiple complex biochemical pathways and reactions that alter drug structure so it can be excreted from the body.
- LIVER is the primary organ for drug metabolism.
- There are different liver enzyme pathways that metabolize medications and this complex is known as P450 system with its isoenzymes.
- These isoenzymes influence the speed that drugs are metabolized.
- Challenges of CYP system- drugs predictability influenced by enzyme inhibition, induction, competition (drug interaction of binding for same site).
15
Q
WHAT ARE SOME FACTORS THAT INFLUENCE METABOLISM?
A
- Drug interactions- some drugs compete for the same site or enzymes; may increase or decrease metabolism and produce unwanted toxicity or subtherapeutic level
- Hepatic dysfunction- patient with liver disease may not be able to metabolize certain drugs
- Patient variability
- First pass effect- drugs are entered into the hepatic portal system circulation, and are inactivated before they reach general circulation. May be problematic, as only a portion of the drug reaching the target.
16
Q
WHAT IS EXCRETION?
A
•Excretion process of removing drugs from the body once it has been metabolized
•Rate of excretion determines concentration in the blood and its duration of action.
•Primary organ for excretion is the KIDNEY.
* patients with kidney disease usually require dose adjustments
•Excretion may also occur via pulmonary, glandular or fecal routes
17
Q
WHAT ARE TIME RESPONSE RELATIONSHIPS?
A
- Therapeutic range of a drug depends on the concentration of the plasma level to be effective.
- Some medication levels are monitored to measure plasma levels
- Example
- Why is this important?
- Half life (t ½)
- Gives information about drug’s duration on action
- Amount of time it takes the concentration of drug in the body to decrease by 50%
- Range from minutes to hours to days
- Influences dosing intervals
18
Q
WHAT IS PHARMACODYNAMICS and PHARMACOGENETICS?
A
- Pharmacodynamics- how a drug changes the body (desired or undesired)
- Patients have different responses to a medication
- Pharmacogenetics- specialized study examines roles of genetics in drug response
- Receptors- most drugs produce change by activating or inhibiting receptors at the cellular level and are the target site for drug binding
- What happens is a drug binds to a chemical receptor at the cellular level and causes a change in physiology, either enhancing a reaction or inhibiting I cellular receptors
19
Q
AGONISTS AND ANTAGONISTS?
A
- When a drug binds to a receptor it may have the following changes:
- Agonist (synergistic effect)- medication activates receptor and produces same response as an endogenous substance; thus, potentiates or increases response
- Partial agonist- weaker response, but still increased
- Antagonist- blocks body’s receptor site via competition; used when the body or a drug overdose is producing too much of a response
20
Q
WHAT ARE POTENCY AND EFFICACY?
A
•Words used to describe a drug’s activity:
- Potency- the amount of drug needed to produce the intended effect
- Efficacy- greatest maximal response
21
Q
WHAT ARE ADVERSE DRUG EFFECT?
A
- ADE- undesirable occurrence caused by administration of a medication; intense and disabling
- Serious ADE results in: patient death, hospitalization, or disability; congenital abnormality; life-threatening; requires an intervention to prevent permanent damage
- FDA Black Box Warning: warning to prescribers that the drug carries a risk of serious or fatal adverse effects
- Example- Fluoroquinolone antibiotics (brand names Cipro and Levaquin), tend to cause tendon ruptures.
22
Q
WHAT ARE SIDE EFECTS?
A
- Side Effect: types of drug effects that are predictable even at therapeutic doses; annoying or minor side effects
- Some examples- nausea, diarrhea, constipation, lightheadedness, sensitivity to sunlight
23
Q
ADVERSE DRUG EFFECTS MAY OR NOT BE THE RESULT OF ERRORS?
A
- May or may not be result of errors:
- Pharmacological reaction
- Hypersensitivity (allergic) reaction
- Idiosyncratic- unexpected, not a normal reaction for that drug due to genetic differences in people
- Drug causing cancer or teratogenic (birth) defects
- Drug toxicity may target organs; if you know the organ you can anticipate which signs and symptoms to look for
- examples- nephrotoxic, neurotoxic, hepatotoxic, dermatological, bone marrow, skeletal muscle, cardiotoxic
- Nephrotoxic- may see color and volume changes in urine
24
Q
WHAT ARE DRUG INTERACTIONS AND SOME TYPES OF THEM?
A
- Drug interaction- when a substance increases or decreases drug’s actions. May be another drug, dietary supplement, an herbal product of food.
- Drug interactions include changes in ADME of medications.
- Additive effect: 1+1 =2
- Synergistic effect: 1+1=3
- Antagonist effect: 1+1=0
25
WHAT ARE MEDICATION ERRORS?
•Preventable ADE by using 10 Rights of Medications:
1. Right dose
2. Right medication
3. Right patient
4. Right route
5. Right time
6. Right patient education
7. Right documentation
8. Right of patient to refuse medication
9. Right assessment prior to administering
10. Right evaluation following dose
26
WHAT TO DO WHEN GIVING MEDICATIONS?
* Documentation in military time to prevent confusion
* Scheduled drug- must be given 30 minutes before or after it is scheduled
* Stat drug order- needs to be given within 30 minutes or less of order
* PRN- as needed medications
* Miscellaneous:
* IM drugs- also include site, example deltoid, gluteal
* JCAHO requirement- evaluation of pain after one hour of medication administration documented
* Patient refusal- free text in paper documentation why
27
NURSING RESPONSIBILITIES IN PREVENTING MEDICATION ERRORS?
* Nurse responsible to know the following when giving a medication:
* Classification
* Action
* Route
* Normal dose-
* watch trailing zero; use 1 mg, NOT 1.0 mg
* ALWAYS use leading zero; use 0.25 mg, NOT .25mg
* Side effects
* Contraindications
* Incompatibilities
* Interactions
* Nursing implications
28
GENERAL METHODS TO PREVENT MEDICATION ERRORS
* Minimize verbal or telephone orders
* Repeat order to prescriber
* Spell drug name aloud
* Speak slowly and clearly
* List indication next to each order
* Avoid medical shorthand, including abbreviations and acronyms
* Never assume anything about items not specified in a drug order (i.e., route)
* Do not hesitate to question a medication order for any reason when in doubt
* Do not try to decipher illegibly written orders; contact prescriber for clarification
29
ADDICTION
DEPENDENCE
WITHDRAWAL SYMPTOMS
TOLERANCE
* Addiction- overwhelming compulsion to repeat drug use
* Dependence- continued drug-seeking behavior despite negative health and social consequences
* Withdrawal symptoms- symptoms that occur when the abused substance is stopped
* Tolerance- occurs when the body adapts to the drug and a larger dose is required to yield the effect
30
WHAT ARE THE 5 CATEGORIES OF CONTROLLED SUBSTANCES?
* Controlled substances are restricted and classified according to their potential for abuse and toxicity.
* 5 categories (uses Roman Numerals) I, II,III, IV, V
* I- Severe risk for dependency, Rx only with approved protocol (examples- Heroin, LSD, Marijuana)
* II- Severe physical and psychological risk for dependency Written Rx only (examples-Codeine, Cocaine, Methadone, Morphine, Oxycodone, amphetamines - Adderall)
* III- Moderate/low risk for physical +/or psychological dependency (examples- fiorinal, anabolic steroids)
* IV- Limited physical or psychological risk ( examples- Tramadol, Xanax, benzodiazepines)
* V- Limited risk for physical or psychological. May be written Rx or OTC depends on state law (examples- cough meds, diarrhea aids, with limited amount of narcotics).
31
WHAT IS THE NURSING PROCESS?
ADPIE
- Assessment
- Diagnosis
- Planning
- Implementation
- Evaluation
- Assessment
32
WHAT ARE THE FDA PREGNANCY CATEGORY RATINGS?
* Category A- considered safe for use in pregnancy (Adequate and well-controlled studies have failed to demonstrate a risk to the fetus)
* Category B- considered safe for use in pregnancy (Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women)
* Category C- should be avoided during pregnancy; insufficient data availability to determine drug safety (Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans)
* Category D- should be avoided during pregnancy; known risk to human fetus, but potential benefits may outweigh risk.
* Category X- should be avoided during pregnancy; known risk of birth defects
33
WHAT ARE SOME THIMGS TO THINK ABOUT WHEN LOOKING AT PHARMACOTHERAPY IN OLDER ADULTS?
* Some Principles for Older Adult:
* GI system motility slows and will affect absorption
* Diminished cardiac output slows circulation of nutrients and drugs
* Nervous system blood brain barrier declines allowing more substance in to the CNS
* Renal function declines and the body may retain medications longer
* Muscle mass may deteriorate altering body water and distribution
* Albumin levels may decline, which affects protein binding; thus increasing the amount of free drug (remember it is the free drug or the unbound drug that has receptor interaction)
* Increase sensitivity to medications and more pronounced adverse effects
34
WHAT ARE SOME CULTURAL CONSIDERATIONS?
* Cultural influences include:
* Genetic factors may affect absorption and metabolism of drugs
* Health beliefs and practices
* Past use of medicine
* Religious practices
* Folk remedies
* Home remedies
* Response to treatment
