week 3: pharmacology

what are the 3 drug classification?

• chemical name

• generic name

• brand name

what is a chemical name?

• chemistry nomenclature

  • exact description/chemical compound

• ex. N-Acetyl-para-aminophenol

what is a generic name?

• unique and most universal; class

• ex. Acetaminophen (Antipyretic/Non-opioid)

what is a brand name?

• marketing name

  • trade or business

• ex. Tylenol

since Tylenol can be effective for treating pain and fever, it is classified as both?

• analgesic (pain reliever)

• antipyretic (fever reducer)

what different groups are drugs classified into based on?

• therapeutic use

• mechanism of action

• legal scheduling

• psychoactive effect on the body

what is the Health Protection Branch (HPD) of Federal government?

• federal authority within Health Canada responsible for regulating, evaluating, and monitoring the safety of medications

what are medication standards?

• federal legislation (Food & Drug Act (FDA)) → standards for manufacturing & sale of all food/cosmetics/medications/certain medical devices

• Canada Formulary → officially sets standards for medication quality/packaging/safety

  • is it safe and efficient?

  • any adverse side effects

what are medication controls?

• Controlled Drugs & Substances Act (CDSA)

  • abuse or dependence?

do nurses in MB have legal authorization to perform medication administration?

• yes, they have to operate within federal and provincial regulations

  • high risk medication?

  • controlled substance?

• 2 nurses need to check high dose drugs before it reaches a patient

what is the definition if inpatient?

• you are admitted to a hospital or residential facility and stay overnight

• medications that we administer

what does inpatient medication include?

• prescriber orders

  • what exactly has been ordered

• administration records

  • helps tract medications, how much, who gave, what route?

what is the definition of outpatient

• you receive medical treatment, therapy, or diagnostic test but go home on the same day

what does outpatient medication include?

• prescription

  • regulate

  • to be used by ONE person only

  • ordered by family doctor and administered by pharmacy

• behind the counter

  • don’t require a prescription but bit more risky and requires ID

    • can become addicting

  • dependent

  • i.e. gravol and plan B

• over the counter (OTC)

  • Tylenol, Alive

    • can be bought on shelf and no ID and no lmits

in obtaining inpatient and outpatient medication what must prescriber orders and perscriptions clearly include?

• patient details (specifics about who this is for?

• drug info (name, dose, form/route, frequency, total quantity if applicable)

• prescriber info (name, professional registration and license #)

  • who made the order?

• authorization (date and signature)

what is the “ideal drug”

• achieves the therapeutic objective → “do the most good/benefit with minimal harm”

• DOES NOT EXIST

what is the “big 3” in ideal drugs?

• effective

• safe

• selective

what is expected in for effective in an ideal drug?

• elicits the response for which it’s given

• justifies the need for it

what is expected for safe in an indeal drug?

• cannot cause harm (inevitable with high doses and prolonged use)

• reduction of harm by proper drug selection and dosing

• benefit > potential risks

what is expected in selective for an ideal drug?

• elicits only the response for which it is given

additional “ideal drug” properties include

• reversible

  • don’t want antibiotics to be reversible

• predictable

  • know exactly how patient will react

• ease of administration

  • oral is the best method f

• lack of drug interactions

  • polypharmacy (more than 2 drugs being taken)

• low cost

• chemical stability

  • stay for very long time where they are

what are nurses accountable for knowing?

• what meds are prescribed

• med purpose (why are they taking it?)

• appropriate dosages and routes

• therapeutic and adverse effects

• assessment and monitoring requirements

• patient education needs

• if the patient is appropriate for this patient at this time

what are we thinking about when performing a patient physical assessment?

• think about how the drug works

• what should you assess?

• does this patient have any risk factors

• is the drug safe to give

• will it have time to have adverse effects

• allergies?

what are we thinking about when performing an analysis?

• is the medication safe to give right now? why/why not?

• if hypotensive NOT safe to give bp meds

when planning what do we think about?

• is med safe to give? → how/when will you give it

• if multiple meds are due at once, which is highest priority

• what should the drug do?

• what could it do?

• do you need to monitor after? for what/when

• med not safe to give → why? who did you notify and next steps

  • need to tell immediately, bad to withhold

what do we do in implementation?

• medication admin

  • 10 rights of medication administration

what do we reflect on during evaluation?

• was the medication effective? → did we achieve the intended therapeutic effect?

• what info do we need to gather to determine that?

• patient education needed?

  
  

what are the 10 right medication administration?

1. the right medication

2. the right dose

3. the right patient

4. the right route

5. the right time and frequency

• critical to check done 3 times before given

6. the right documentation

7. the right reason

8. the right to refuse

9. the right patient education

10. the right evaluation

• speak to before medication administered

what can be found on a patient care card of physician’s orders?

• drug name (s)

• dosage

• route

• time

• patient name

what are medication errors?

• any preventable event that may cause or lead to inappropriate medications use or patient harm while the medication is in the control of the healthcare professional, patient, or consumer

what are types of medication errors?

• wrong patient

• wrong drug

• wrong route

• wrong time

• wrong dose - omitted dose - wrong dosage form

what are causes of medication errors?

• human error

• communication mistakes (documented and orders)

• name confusion

what are ways of prevention of medical errors?

• institutional culture

• infrastructure

• clinical practice

• technology

application of pharmacology in patient care - nursing assessment and considerations

• pre-administration assessment

• dosage and administration

• promoting therapeutic effects

• minimize adverse effects

• minimizing adverse interactions

• making PRN decisions

• evaluating responses to medication

• managing toxicity

what do we do in pre-administration assessment?

• collect baseline data

• identifying high risk patients

what do we think about when collecting baseline data?

• what should I assess for that might indicate

  1. therapeutic effect (i.e.169/92 → 138/83)

  2. adverse effects

• how do I know what to assess for?

  • need to know what this drug does/the effects it is likely to produce

identifying high risk patients

• pathophysiology

• generic factors

• drug allergies

• life span considerations (young/old/pregnancy)

  • age related deteriorations

• how to identify? (who at higher risk of reacting adversely)

  • patient history

  • physical assessment

  • laboratory data

• how do I know what risk(s) to look for?

  • need to know how the drug works and what risk factors could increase the risk of severe reactions

what are guidlines for administration?

• clarify any unclear orders

• confirm checks with required data sources…

• verify any dosage calculations (double check your work!!)

• do not administer any drug if you don’t know what it is for or how it works!!

  • if no order sheet stamped with patient name and/if no wrist band always double check

what do we need to considered with dosage and aministration?

• must be familiar with 10 medication rights and appropriately carry these out for safe medication administration

  • is it safe for me to do at this time

  • what kind of route?

→

• cannot be safely implemented without knowledge of pharmacology

what are some nonpharmacological approaches?

• breathing exercises

• positioning

• emotional support

• exercise

• rest

• diet restrictions

• ex. broken ankle

  • already have pain meds

  • rest

what must you know when administering drugs?

1. major adverse effects

2. when reactions could occur

3. early/warning signs

4. interventions to minimize harm

what can we considered to minimize adverse effects?

• identify high risk patients

• ensure proper administration

• patient education → what to avoid?

• what could affects be

• early signs

• do not give drug if you don’t know side effects

patients who are taking 2 or more medications (polypharmacy) are potentially at risk!

how can we help reduce the risk?

• take a thorough drug history

• patient education

  • avoid OTC drugs that are known to interact

  • what signs to watch out for re: interaction effects

• monitoring for adverse interactions known to occur between drugs (could make things worse)

making PRN decisions

• as needed, dose range, time range

• nurse use discretion

  • when to give?

  • how much to give?

• know

  • reason of drug

  • assess patient’s needs

    • is it harm

    • did we get therapeutic effect?

evaluating responses to medications

• was it beneficial or harmful?

• know

  • rationale for drug

  • onset of action

  • what to do when it is harmful

managing toxicity

• extremely dangerous

  • someone had too much

  • drug is known

• know

  • early signs

  • procedure for toxicity management

mechanism of action

• summarizes how drug works at the molecular/biochemical level to produce a pharmacological effect within the body. includes what enzyme, receptor, or neurotransmitter (s) the drug binds to or modulates

nursing considerations

• key components/knowledge required by the nurse to safely administer a drug

• may include assessments, monitoring/evaluation, administration specifics, contraindications, and required education

indications

• the specific disease (s), symptom (s), or condition (s) a medication is officially approved to treat/prevent/cure

contraindications

• the specific condition (s) or circumstance (s) which makes a specific drug particularly harmful

therapeutic effects

• the intended/expected outcome of a medication has positively affected the patient’s health/symptoms/disease management

adverse drug effect

• any noxious, unintended, and undesired effect that occurs at normal drug doses

• can range from mild to severe and life-threatening

toxicity: excessive dosage (OD)

• detrimental effect from overdose

  • ex. hypoglycemia from insulin

toxicity: organ-specific

• drugs which damage specific organs

  • hepatotoxic → can cause liver damage

  • nephrotoxic → can damage kidneys

  • cardiotoxic → can damage the heart or alter function

allergic reaction

• immune response to a drug

• intensity of reaction = degree of sensitization of immune system

paradoxical effect

• drug has opposite effect of intended drug response

physical dependence

• body has adapted to drug exposure; abrupt discontinuation can cause an “abstinence” syndrome

carcinogenic

• ability to cause cancer(s) in one’s lifetime

tetratogenic

• ability to induce birth defects/abnormal fetal development or demise if taken while pregnant

what should we consider when providing patient education?

• no medical jargon

  • use simplest way to breakdown to a patient

• dosage and administration

  • when and how they will take it

• promoting therapeutic effects

  • rest, ice, evaluation

• minimize adverse effects and interactions

  • education patients on drugs they are on

    • stay away from

    • adverse effects: what to expect

What does the nurse do during the Assess and Analyze steps?

Assess:

• Is the patient’s BP high?

• Is it related to hypertension?

• Could it be related to a head injury?

Analyze:

• Determine the likely cause of the findings.

• Example: headache may be related to high BP.

How does the nurse plan care for a patient with a headache related to high BP?

• Goal: reduce pain/headache

• If related to high BP → work to reduce BP

• Check MAR for medication orders

• Review history for risks/contraindications

• Consider whether PO medication is safe, especially with poor LOC

What does the nurse do when implementing and evaluating the intervention?

• Implement:

  • Administer acetaminophen 500 mg PO PRN using the 10 Rights

  Evaluate:

  • Reassess after 30–45 minutes

  • Patient reports pain is relieved

administration

• medication errors

• patient adherence

pharmacokinetics

• absorption

• distribution

• metabolism

• excretion

• how much of administered dose gets to site

• movement of drug in body and body effect

pharmacodynamics

• drug-receptor interaction

• patient’s functional state

• placebo effect

• effect of drug in the body

• bind drug to receptor

sources of individual variation

• physiologic variables

  • weight

• pathologic variables

  • impaired and/or kidney function

• genetic variables

pharmacokinetics 4 stages

• absorption

  • drug movement from site of administration to blood stream

• distribution

  • blood stream, from blood to target cells

• metabolism

  • breaking down drugs structure

  • increase likelihood of being peed out

• excretion

**all 4 phases involves drug movement and membrane corssing

how does pharmacokinetics passage of drugs across membranes?

• channel/pores

  • only very ting things and specific of what comes through

• transport systems

  • move from one side to another

  • very selective

  • uses ATP

• direction penetration (main means)

  • lipid soluble vs water soluble

  • ionized vs nonionized

    • pH dependent

non-ionized

• lipid-soluble and easily crosses membrane

ionized

• water soluble and will not cross membrane easily

  • pH of environment may ionize drug

acidic drug: acidic environment

• nonionized

acidic drug: basic/alkaline environment

• ionized

basic drug: acidic environment

• ionized

basic drug: basic/alkaline environment

• nonionzed

stomach pH

ex. aspirin (ASA)

• is LOW (acidic) pH 1-3

• therefore, ASA is nonionized in this environment and crosses cell membrane of stomach epithelial cells

small intestine pH

ex. aspirin (ASA)

• is HIGH (alkaline) pH 6-7.5

• therefore, ASA is ionized in this environment and absorption of ASA from the intestines is impeded

how is food a pH buffer?

• empty stomach = lower pH

• with food = higher pH (less acidic)

• take certain meds with food and some without

some oral medication considerations include

• take with food

• take on empty stomach

• do not crush - enteric coated

• do not crush - sustained released

environment pH can affect drug ionization

• therefore if or how fast it will cross membranes

  • drug properties may require specific pH for absorption speeds or locations within the GI tract

  • take food with a medication can help reduce damage

enteric coated

• protective barrier to prevent drug from being dissolved and absorbed in the stomach

• DO NOT CRUSH

sustained release

• capsules designed for slow and steady drug release

• DO NOT CRUSH

what is absorption affected by?

• rate of dissolution

• surface area

• blood flow

• lipid solubility

• pH partitioning

rate of dissolution

• faster drug dissolves = faster it can be absorbed

absorption: surface area

• larger the surface area (of admin site) = faster absorption

absorption site: blood flow

• High flow/vascularity = faster absorption

absorption site: lipid solubility

• Highly lipid-soluble drugs cross membranes faster = faster absorption

• crosses lipid membranes faster

absorption: pH partitioning

• When the difference in pH of plasma & admin site makes it more likely the drug molecules will be ionized in the plasma = faster absorption. (aka ion trapping).

• pH on one side different than other

  • pH particles

  • go to favours

what are the routes of administration?

• enteral

• parental

• other

enteral: oral (PO)

• easy, convenient, inexpensive way to take medications. Absorption highly variable d/t:

  • 2 barriers to cross: Epithelial cells lining GI tract & Capillary wall. (cells quiet permeable, BBB)

  • Inactivation/drug losses from digestive enzymes or liver metabolism (first pass effect, part of drug lost or passed) (move through cells that cant absorb)

enteral: sublingual/buccal

• (under tongue or back of cheek; tablet or spray) (absorbed, not digested)

  • don’t involve digestion

  • oral mucus is quick

eternal: rectal

• suppository or enema (absorbed, not digested)

parenteral: intravenous IV

• rapid and complete

parenteral: intramuscular (IM)

• absorption can be rapid or slow; drugs pass directly through capillary wall.

  • deep into muscle

  • big gaps between cells

parenteral: subcutaneous (subQ or subcut)

• absorption can be fast or slow; drugs pass directly through capillary wall

• pass between cells of capillary beds

• high absorption

route of administration: topical

• ointment/cream; must move through skin layers through capillary walls.

route of administration: transdermal

• similar to topical but medication is in patch-form

  • clear like patch

  • applied to skim

  • systematically

route of administration: inhalation

• inhaled aerosolized drug deposited into lungs & crosses capillary walls

  • pass to alveoli

What is drug distribution?

• Distribution = movement of a drug from the bloodstream to the tissues/site of action.

  • Better blood flow/perfusion → better drug distribution

  • Drug travels through the circulation to the target organ/tissue

How does a drug leave the vascular system to reach tissues?

• Drug reaches the target organ/tissue

• Leaves the blood through capillary beds

• Most capillary walls allow drug movement through their large pores

• Exception: Blood-brain barrier (BBB) is more restrictive