Three most important properties of an Ideal Drug:
1. Effectiveness (efficacy) mechanism of action
2. Safety
3. Selectivity: drug elicits only the response for which it is given. The more selecctive the more
preferable.
- Predictability
- Ease of administration, the more likely compliance, adherence
- Chemical stability
- Reversible action
- Freedom from drug interactions’
- Low cost
- No drug is completely ideal
- Drug is still effective even if it has side effects
● Factors that determine the intensity of drug responses:
- Administration (better compliance)
- Pharmacokinetics(absorption, distribution, metabolism, excrretion etc 4 processes)
- Pharmacodynamics
- Sources of individual variation
For missed doses always start with re-education
Pharmokinetics:
How the body is impacting the drug (ADME)
Absorption
Distribution
Metabolism
excretion
Pharmodynamics:
Drug receptor interaction(the binding of the drug to its receptor/enzyme). Concerned with the effects of
drugs and their mechanism of action.
Placebo effect- also help to determine the responses a drug induces
Physiological (age, gender, weight) the nurse should evaluate variability as it may affect response
Genetics play role in metabolism
Sources of individual variation:
-physiological values(age, weight, height)
- pathological values(diminished function of kidneys & liver)1
-genetic variables
-drug interactions
Administration:
-dosage size, route, and timing
- the more ease of administration, the more likely that the patient will comply to the medication.
- for missed doses, always begin with re-education to the patient
Next powerpointL
6 rights of nursing responsibilities regarding drugs:
Right drug
Right patient
Right dose
Right time
Right route
Right documentation **prn med**
The nurse must know:
What medications are appropiate for the patient
What drugs are contraindicated for the patient
What are the probable consequences of the patient taking the prescribed drug
Nurse-last line of defense
Factors that affect physiological response:
Age, gender, and genetics affect a person’s ability to absorb and excrete a drug. Weight affects
distribution of the drug.
Patient care:
Collecting baseline data
--- compare baseline data v. post adminstration
Weight not height is important for drug distribution
-identifying high risk patients:
Kidney and liver impairment (drugs will not be excreted=drug accumulation because kidney filtrates
urine)
Other high risk patients include: Drug allergies, genetic factors, pregnancy, and older adult or pediatric
group.
Two main populations to be aware of: pediatrics and geriactrics
extravasation= drug leaks out into surrounding tissue
Patient identification: wrist band and oral identification
Certain antibiotics take a few hours while thyroid drugs can take a few weeks to work,
Always question compliance ( quantity and frequency) of patients how often and how much they take.
Never change or suggest a change in dosage unless prescriber tells you to.
Always know the following:
The major adverse effects that drugs can produce (anflaxis- wheezing hives) discontinue medication give
them benydryl.
- Take a thorough drug history.. Opoid and tynenol in overthecounter drugs, which can lead to
overdose with medication. Max daily dose of tynenol to 4 grams a day unless they have liver
problems it should be 2 grams a day (avoid overthecounter drugs)
Making prn decisions:
-Means as needed
- doses are not fixed
How much drug to give and when to give it
Know the reason for drug’s use
- Narcotics for increased pain not tynenol(500mg as needed for mild pain)
- Documentation to prevent overuse
Patient Education:
-drug name (never use brand name just generic)
- dosage size and schedule of administration
- route and technique of administration
Expected therapeutic response and when it should develop
Nondrug measures to enhance therapeutic responses(empty stomach with food,e tc)
Duration of treatment
Adverse effects (both harmful and unharmful)
-drugs interfere with diet
-vitamin k produce in liver.
Landmark Drug Legislation (3rd powerpoint)
5 different classes:
- CI : no medical purpose/use (controlled substance)
- CII: narcotics (wont get refills max of 30 days) alderol adhd, opoid (most abuse potential)
schedule substance
- CIII: control substance
- CIV: control substance
- CV: least abuse potential. Control substance
-preclinical testing: use in humans is not yet alllowed. Safery and usefulneess not yet known
Phase 1: given on healthy volunteers. Phase 2 &3: given on sick volunteers
-Just because a drug has the same trade/ brand name, must check active ingredients because will contain
different ingredients.
Pharmacokinetics:
Is the study of drug movement throughout the body
- Time course of drug responses
- ADME (absorption,etc)
Absorption- GI tract
Three ways to cross a cell membrane:
Channels and pores
Tranport system
*p-glycoprotein: transmembrane protein that transports a wide variety of drugs out of cells
- Most drugs are too large to pass through channels or pores
- Like dissolves like
- Most drugs are described as a weak acid
- Ionization & excretion
- Aspirin-weak acid
- Put it in a basic environment so it ionized
Ionization bad for absorption
- When basic drug(alkaline) in basic environment- unionization -lipid soluble :)
- Aspirin (weak acid) if want drug to be unionized must be in acidic environment (manipulate pH)
- When aspirin goes to stomach(acidic environment), absorption will occur.
- When want to promote excretion, water soluble (hydrophilic) & lypophobic drugs in ionized
form
- IV(Intravenous):
● Fastest route for absorption
● When fast action is needed STAT- severe acute pain (ie. morphine sulfate or merperidine
(demerol))
-
- Drug A: NEXT TO NAME U SEE:
XL: SWALLOW WHOLE DO NOT CRUSH OR CHEW
XR: SWALLOW WHOLE DO NOT CRUSH OR CHEW
ER: SWALLOW WHOLE DO NOT CRUSH OR CHEW
SR: SWALLOW WHOLE DO NOT CRUSH OR CHEW
SA: SWALLOW WHOLE DO NOT CRUSH OR CHEW
PA: SWALLOW WHOLE DO NOT CRUSH OR CHEW
Sublingual (SL)-under the tongue
Buccal: inside the cheek
For blood flow: be advised of abscesses(must be drained) and tumors(restricted blood supply)
Infants do not have blood-brain barrier (most at risk)
- Most abundant protein in body is albumin. If drug is bound it cannot participate in processes
(absorption, etc)
*Organ responsible for metabolism is the liver.*
- A lot of drugs cannot take with grapefruit juice, because it inhibits metabolism.
- Liver can activate or inactivate drug
Half-life of a drug:
- Drugs with longer half lives (24 hours or more)= lesser dosages
- Drugs with shorter half lives requires frequent dosages to keep up with minimum effective
concentration.
- Plateou( or steady state) exists after 4 half-lives
