How can drugs be administered?
What are the three phases drugs act orally?
What are the four processes during the dissolution phase that achieves drug action?
What do drugs do in the absorption phase?
during the absorption phase, movement of drug particles go from the GI tract to body fluids.
What kinds of absorption are there?
- passive absorption-primarily diffusion
- active absorption-requires carrier
- pinocytosis-cells cary drugs across the membrane
What affects absorption?
- lipids and non-ionized absorb faster
- pain, stress, food effect absorption
- im drugs absorv faster in muscles with more blood vesssels
- S.Q. absorb slower
What does bioavailability mean?
- Bioavailability is the percentage of drug that reaches circulation.
- orally less than 100%
- IV usually 100%
What are the factors that alter bioavailability?
- drug form
- route of administration
- GI mucosa with motility
- food, other drugs
- changes in liver metabolism
What is distribution of drugs?
process by which drug becomes available to body fluids/tissues
How is the distribution of drugs influenced?
- influenced by
- blood flow
- tissue affinity
- protein-binding effect
What is a protein-binding effect?
- drugs bound to protein in varying degrees
- portion of drug bound is inactive
- free drugs active with cause pharmacologic response
- two highly protein-bound drugs concurrently compete
How are drugs metabolized?
- liver primary site
- most drugs inactivated by liver enzymes then converted
- time it takes for ½ of the drug concentrate to be eliminated.
How are drugs excreted?
- main route kidneys
- other routes include:
- hepatic, bile, feces, lungs, saliva, sweat, breast milk
- protein-bound not filtered through kidneys
What does kidney disease result in?
What does creatinine clearance determine?
- determines renal function
- varies with age and gender
- normal 85-135 ml/min.
What is the Pharmacodynamic phase?
- study of drug concentration and body effects
- includes primary and secondary effects
- primary = desirable
- secondary = undesirable
What are the 10 pharmacodynamic phases?
- 1. dose response and maximal efficacy
- 2.onset, peak, duration
- 3.receptor theory
- 4.therapeutic index/range
- 5.peak and trough levels
- 6.loading dose
- 7.side effects/reactions
- 10.placebo effect
What is the dose response?
- relationship between minimum and maximum amount of drug needed to produce desired response
- maximal efficacy
What do onset, peak, and duration mean?
- onset—time it takes to reach minimum effective concentration
- peak—highest blood concentration
- duration—length of pharmacologic effect
What is the receptor theory?
- 4 receptor families
- ligand—gated ion channels
- G protein—coupled
- act through receptors to initiate or block responses
What are the 2 receptor theory responses?
- Agonists—produce response
- Antagonists—block response
- lack specific and selective effects
What are the 4 categories of drug action?
- inhibition or killing
What does the length of action depend on?
the half-life of a drug
What is the therapeutic index?
- estimates margin of safety
- ration measures the effective dose and the lethal dose
- closer the ratio to 1, the greater the danger
- low therapeutic index = narrow margin of safety
- high therapeutic index = wide margin
What are the peak and trough levels?
- peak level = highest plasma concentration
- indicate the rate of absorption
- trough level = lowest concentration
- measures rate at which drug eliminated
- drawn immediately before next dose
- use for drugs with low therapeutic index
What is a loading dose?
- immediate response desired
- Side Effects
- not related to desired drug effects
- all drugs
- Adverse Reactions
- more severe
- always undesirable
- must be reported
- monitor plasma
What does pharmacogentics mean
- effect of drug that varies from a predicted drug response
- hereditary or genetic factors
- African-Americans and Ace inhibitors
What is the tolerance phase?
- decreased responsiveness
- tachyphylaxis = rapid ↓
- narcotics, barbiturates, laxatives, psychotropics
What is a placebo effect?
- psychological benefit from compound
- 1/3 of persons benefit
- participants told they may receive placebo
- participants told they may receive placebo
A tablet undergoes which of the following two processes before it is absorbed?
- metabolism, dissolution
- disintegration, distribution
- biotransformation, distribution
- +disintegration, dissolution
Steps in the Nursing Process
What processes are in the assessment phase?
- subjective/objective data
- ask about prescriptions, vitamins, herbs, contraceptives, ASA, antihistamines, caffeine, nicotine
- assess major organs for signs of reaction
- identify high risk clients
- nursing diagnosis?
What is in the planning phase?
- characterized by goal setting
- develop interventions
- effective goals
- client centered
- realistic deadlines
- need to be evaluated
What is in the implementation phase?
- nursing actions/interventions to accomplish goals
- client education/teaching are key
- including family or friends = excellent idea
- client teaching may include:
- general information
- self administration
- side effects
- cultural considerations
- charts, pictures, graphs
- community resources
What is in the evaluation phase?
- address effectiveness and attainment of goals
- goals not met, revise
You record client teaching in which phase of the nursing process?
in the implementation phase
Principles of Drug Administration
- nurses are accountable for safe administration of medications
- know all components of a drug order
- legally liable for incorrect or contraindicated drug
- liable for predicted effects
The Five Rights of Drug Administration:
- Right Client
- Right Drug
- Right Dose
- Right Time
- Right Route
2 forms of ID
- drug prescribed
- telephone or verbal order cosigned within 24-hours
- components of a drug order:
- drug name
- route of administration
- special instructions
- physician or HCP signature or name (T.O., V. O.)
- signature of practitioner taking order
- read label three (3) times
- time of contact with bottle/container
- before pouring
- after pouring
- know reason for getting medication
Four main categories of drug orders:
- ongoing, given for specific number of doses
- PRN as needed
- client request
- STAT = at once
- dose prescribed for particular client
- nurse calculates correctly
- stock method or unit dose method frequently used
- twice a day = (bid)
- three times a day = (tid)
- four times a day = (qid)
- every 6 hours = (q6h)
- military time
- administration of drugs 0.5 hours before or after time prescribed
- check for testing, expiration, gastric irritation
- oral = by mouth
- sublingual = under tongue
- buccal = between gum and cheek
- inhalation = aerosol
- topical = applied to skin
- instillation = nose, eye, ear
- suppository = rectal, vaginal
- parenteral = IM, SQ, IV
- assess ability to swallow
- no mixing without consulting pharmacist
- aseptic technique
- make sure medicine is swallowed
- right assessment
- appropriate data collected
- right documentation
- document adm./response
- right to education
- knowledge of medication
- right evaluation
- expected outcome?
- right to refuse
Tablets and Capsules
- not given if vomiting, lack gag reflex, comatose
- enteric and time-released swallowed whole
- adm. irritating with food
- empty stomach if food interferes
- sublingually remain
- elixirs = sweet
- emulsions = mixture
- suspensions = particles mixed
- dilution or shaking required
- meniscus is at the line of desired dose
- many require refrigeration
- stored in a patch placed on skin
- systemic effect
- more consistent blood levels
- avoid GI upset
- should be rotated
- cutting not recommended
- applied to skin via glove, tongue blade, or applicator
- no double-dipping
- liquids usually administered as drops, ointments, or sprays
- eye drops = expose conjuctival sac
- ear drops—adult
- up and back
- ear drops—child
- down and out
- nose drops
- keep head tilted back
- preferred position is semi or high Fowler’s
- nebulizers (aerosols) change liquid into mist
- metered-dose inhaler (MDI) convenient
- many MDI’s use spacers
- check for proper placement
- flush tubing after medication
- rectally for local and systemic absorption
- client lies on left side and breaths through mouth
- lie on side for 20 mins. after insertion
- vaginal = lithotomy position
- local effect
- used for observation of inflammatory reaction
- TB testing, allergies, immunotherapy
- clavicular, scapular, ventral mid-forearm
- usually slower onset than IM
- small doses of non-irritating, water-soluble drugs
- abdomen, upper hips, upper back, lateral-upper arms, lateral thighs
- rotate sites
- used for irritating drugs, aqueous solutions, solutions in oil
- ventrogluteal, dorsogluteal, deltoid, vastus laterals
- assess for adequate muscle
- prevents medication from leaking back into SQ tissue
- gluteal site preferred
- pull skin, hold, inject medication, withdraw needle, release skin
- more rapid than IM, SQ
- cephalic, cubital, dorsal veins preferred
Joint Commission announced hospitals no longer use these abbreviations:
- always use zero “0” before a decimal point
- no decimal point or zero “0” after whole number
Your client refuses to take his prescribed medications. The nurse’s best response is to
- explain benefits and side effects of the drug.
- leave medication at bedside to be taken later.
- coerce client into taking medication.
- explain risks of not taking medications.
Digoxin to maintain blood level at 0.5 – 2 nglme.” This is an example of what category of drug?