Administering Medications Flashcards
What are drugs?
“Chemicals that interact with a living organism and alters its activity”
Diagnosis (radiopaque agents, contrast dyes)
Treating
Preventing (immunizations)
Drug Names
Chemical Name
Chemical composition & molecular structure of drug
Rarely used in nursing
Generic Name
Assigned by US Adopted Name Council
ibuprofen
Brand Name (Trade)
Proprietary
Motrin®
Prescription drugs vs non-prescription drugs or over-the-counter (OTC)
ibuprofen 200 vs ibuprofen 800
Drug Classification
Grouped w/similar characteristics Grouped by basic characteristics * Usage * Body system * Chemical composition
One drug can be placed in more than one category
Classified by usage - ibuprofen can be used as an analgesic, anti-inflammatory, or antipyretic
Classified by body system - valium can be used for its anti-anxiety effects or for its effects in decreasing intestinal system activity & other smooth muscles
Promoting Drug Quality and Safety
- Drug listings & directories
- Pharmacopoeia & formularies
- Nursing drug handbooks
- Physician’s Desk Reference
- Pharmacology texts
- A clinical pharmacist; medication package inserts
Promoting Drug Quality and Safety cont’d
- Legal considerations
- US drug legislation
- Sets official drug standards
- Defines prescription drugs
- Regulates controlled substances; improves safety; requires proof of efficacy
Promoting Drug Quality and Safety cont’d
- Nurse Practice Acts
- Identify nursing responsibilities for admin & client monitoring
Food and Drug Administration (FDA) of US DHHS
- Regulates the manufacture & sale of all medications & monitors their safety & effectiveness
- Also regulates, through controlled clinical trials, the testing of any med’n that is to be marketed & sold in the US
Promoting Drug Quality and Safety cont’d
Storing & Distribution Systems
- Stock supply
- Bulk quantity
- Central location
- Not client specific
- Requires measuring each dose
- Cost-effective
Promoting Drug Quality and Safety cont’d
Storing & Distribution Systems
- Unit dose
- Individually packaged
- Client-specific drawers
- 24-hr supply
?
Is the prescribed amount of drug the patient receives at a single time; each one (usually one tablet) is individually packaged & labeled w/drug name, dose, & expiration date
Unit dose
Promoting Drug Quality and Safety cont’d
Storing & Distribution Systems
- Automated dispenser
- Password-accessible locked cart
- Computerized tracking
- Can combine stock & unit doses
- Pyxis or Omnicell
Promoting Drug Quality and Safety cont’d
Storing & Distribution Systems
- Self-administration Medication (S A M)
- Individual containers
- Kept @ client’s bedside
i.e. sublingual nitroglycerin
Pharmacokinetics
What happens to the drug in the body?
- The principles of ADME
Pharmacokinetics
Refers to the absorption, distribution, metabolism, & excretion of a drug
These 4 processes determine the intensity & duration of a drug’s actions
Pharmacokinetics
Absorption
* From site of administration to blood stream
Distribution
* From bloodstream to sites of action
Pharmacokinetics
Metabolism
- Breakdown of medication to be excreted
- Mainly in the liver
Excretion
* Excretion from the body
?
Is the transportation of a dug in bodily fluids (usually the bloodstream) to the various tissues & organs of the body
- Intended & unintended effects can occur
- Rate depends on adequacy of local blood flow in target area; also influenced by permeability of capillaries to drug’s molecules as well as protein-binding capacity of drug
Distribution
?
(or biotransformation); is the chemical inactivation of a drug through its conversion into a more water-soluble compound or into metabolites that can be excreted from the body
Metabolism
Absorption
Factors affecting absorption
- Route of administration
- Drug solubility
- pH/ionization
- Blood flow
The form (preparation) of a drug usually determines its route of administration
?
Refers to the ability of a medication to be transformed into a liquid form that can be absorbed into the bloodstream
Drug solubility
Enteric-coated drugs can’t be decomposed by gastric secretions; the coating thus prevents the med’n from being diluted before it reaches the intestines
In this way, the coating delays the action of the med’n; also decreases irritating effects of the med’n on the stomach
pH (relative acidity or alkalinity) of local environment also affects drug absorption
Acid content of stomach aids in transporting the med’n across the mucous membranes, so acidic med’n, like aspirin, are more readily absorbed in the stomach than basic (alkaline) med’n, like sodium bicarbonate, which are readily absorbed in the more alkaline SI
Ionized molecules are lipid insoluble & thus can’t pass easily through the phospholipid layer of cell membranes
Distribution
Factors affecting distribution
- Local blood flow
- Membrane permeability
- Protein-binding capacity
A drug’s tendency to bind to plasma proteins in the blood also affects distribution. For a given amount of a drug, some molecules bind to plasma proteins, & the remainder will be “free”
Tylenol (nearly all free in bloodstream & are pharmacologically active) vs warfarin (Coumadin) whose effects produced by 1% of molecules that’re free
Metabolism
Factors affecting metabolism
- Liver function
- Health/disease status
- First-pass effect
Metabolism takes place mainly in the liver, but med’ns can be detoxified also in the kidneys, blood plasma, intestinal mucosa, & lungs
First-pass effect
Oral med’ns are absorbed from the GI tract & circulate through the liver before they reach the systemic circulation
Many oral med’ns can be almost completely inactivated this way; this inactivation is known as the first-pass effect
For this reason, oral med’ns formulated w/a higher concentration of the drug than are parenterals
Excretion
Factors affecting excretion
- Organ function, especially the kidneys, liver, & lungs
- Exocrine glands
Common organs of excretion: lungs, exocrine glands, liver, GI tract, & kidneys (primary site of excretion)
Adequate fluid intake facilitates excretion; if decreased renal function (check BUN/creatinine) to monitor for drug toxicity
Exocrine glands (sweat & salivary glands) can also occur w/oral agents
The client has been on a low-protein diet. This will most likely affect which pharmacokinetic process?
a. absorption
b. excretion
c. distribution
d. metabolism
Answer: c
A low-protein diet may lead to an inadequate level of plasma proteins, which will affect availability of “free” drug
Concepts related to Pharmacokinetics
- Time until onset, peak, & duration
- Therapeutic range
- Peak level
- Trough level
- Therapeutic level
- Biological half-life
- Concentration of active drug
Some drugs, like warfarin & digoxin, have narrow therapeutic range. Small dose changes cause therapeutic failure or adverse drug reactions. Blood levels are done frequently in order to know correct drug dosage to give.
?
Is the time needed for drug concentration to reach a high enough blood level for its effects to appear (is the minimum effective concentration)
onset of action
?
When the concentration of medication is highest in the blood, the medication has reached its ___
peak action
___ : period of time in which drug has a therapeutic effect (before metabolized and excreted)
Duration
?
Is the concentration of a drug in the blood serum that produces the desired effect w/o toxicity
Therapeutic range
Is a range of therapeutic concentrations; @ onset of action, serum drug level is minimal
