Medication Administration NUR 100 Ch 35
Household Measures and Metric Equivalents
1 tsp = 5mL 1 Tbs = 3tsp = 15mL 1oz= 2T = 30mL 1cup = 8oz = 240mL 1pt = 16oz = 500ml* 1 qt = 4 cups = 2pts = 32 oz = 1000mL* 1lb = 16oz/ 2.2lb = 1kg
Example of Ratio and Proportion Method
Order (unknown): 40 mg p.o protonix Available (known): 20 mg tablets Solution: known / unknown 20mg /1 tablet = 40mg / x tablet
Example of Dimensional Analysis
Order: 40 mg p.o Lasix daily Available: 20 mg tablets What do you want to find out? How many tablets do I give... Amount to administer = available dose (desired unit on numerator) x ordered dose (in numerator) X tabs = 1tab/20mg x 40mg
Example of Basic formula
Order: 50 mg p.o of Atenolol daily Available: 100 mg tablets Solution: use D/H x Q = x D= 50mg H= 100mg Q= 1 tab
You are the nurse caring for T.L. 49 y.o. Female admitted to the hospital for kidney failure. She is prescribed medications for her blood pressure and her heart rate. These medications are ordered to be administered at 0900. What do you do first? What do you monitor?
Use the measurement System. We monitor vitals- HR, BP etc.
half-life
expected time it takes to measure half of original dose by drug elimination
Category D
fetal risk is evident, benefits may outweigh risks
Category X
fetal risk is evident- risks outweigh benefits- DO NOT GIVE
Peak
highest concentration level in blood- once reached serum levels decrease until administration of next dose
Side effect reactions
predicable, but unwanted and sometimes avoidable. May be minor or harmless.
Controlled Substance Act (CSA)
regulates controlled substances. ○Reduces opportunities for drugs to be diverted from sources to drug abusers ○Monitored by (DEA) Drug Enforced Medication
Pediatric Research Equity Act
require testing for children
Toxic effects
result from medication overdose or build-up of medication in bloodstream from impaired metabolism and excretion.
Adverse Reactions
severe, unintended, unwanted. May occur after one dose or develop over time. (predictable)
What is onset of action? What are the factors?
time it takes for body to respond to the drug after administration ○Factors affecting: route, pharmacokinetic factors, and drug
Allergic Reaction
unpredictable immune response to medication ○Minor- rash, itching, inflammation ○Severe- anaphylactic reaction- medical emergency
Idiosyncratic reaction
unpredictable patient responses ○Over response ○Under response ○Abnormal reaction to medication
International Unit
vitamins
Schedule II drugs
●High potential for abuse, may lead to dependance (both physiologic and psychologic), accepted for treatment with restrictions ○Morphine, methadone, cocaine, hydrocodone, oxycodone
Schedule I drugs
●High potential for abuse, not accepted in U.S. for treatment ○Heroin, LSD, hallucinogens, marijuana
Schedule III drugs
●Lower potential for abuse compared to I & II, moderate dependance risk, accepted for treatment in medical use ○Anabolic steroids,
Schedule IV drugs
●Lower potential for abuse- may lead to dependence -diazepam, alprazolam, benzodiazepines
The drug interactions and compatibility
●Medication Interaction- occurs when drug's action is modified by certain food, herbs, or other medication
Institute for Safe Medication Practices (ISMP)
●Recommends that all medications be prescribed and calculated using metric system ○Differences in dosage measurements can have a serious or harmful impact on the patient ○Used based on measurements of increments of 10
What is pharmacodynamics?
●Studies what the drug does to the body once it reaches the target cite ○Involves receptor binding, post receptor effects and chemical reactions
What is a pharmacokinetic?
●What the body does to the drug for the drug to take appropriate action ●Correlates to the amount or concentration of the drug at the site ●Goal: balance concentration to have effect, but not too much to cause harm
Trade name
●a registered name assigned by the drug manufacture. It can be several different names but still have the same chemical and generic name ●Not able to be used by other manufacturers ●**Usually easier to pronounce and remember**
Household system
●includes oz, tsp, & Tbs: least accurate of measurement system ○Conversion between household and metric should be avoided ○Key conversions are: ■1 ounce= 30ml= 2Tbs ■5mL = 1tsp ■gtt= drop- families should be instructed to use dropper ○** do not use household measurement tool- use medicine cup
What does pharmacology involve?
●involves multiple disciplines including anatomy, chemistry, microbiology, and psychology ○Pharmacology Clinical Pharmacology
Milliequivalents (mEq)
●refers to the ion within the drug ○I.e- potassium, magnesium, calcium, sodium ** You may see U and IU in the hospital- according to The Joint Commission- they are prohibited and must be spelled out**
Apothecary system
●uses units such as grains (abbreviated gr) & minims (m) ○Conversion between apothecary and metric is approximated
Desired drug action
- established when drug level is reached in the body- therapeutic effect
Schedule V drugs
- Low potential for abuse, accepted in medical treatment. - ○OTC cough medicine, opioide controlled substances
Distribution
- drug moving from bloodstream into tissue and site of action
Trough
- lowest concentration level in blood
Units
- refer to amount of drug dissolved in 1mL of solution ○I.e- Insulin, heparin
What is potency and what are the two potencies?
- the amount of drug needed to create a response to another drug. ○High potency- allows small amount of drug to have large effect ○Low potency- minimal effect at low concentration
Ratio and Proportion Method
-Convert all units of measure to the same measurement and size -Set up a proportion -Left side: state known ratio: dose or strength information from medication label/quantity of medication on hand -Right side: state unknown ratio: medication or desired dose/amount or volume to be given (this is the X) -Label all terms in the ratio- including the X -Be sure to write the ratio in the same sequence of measurements -I.e mg/mL : mg/mL -Cross multiply and solve for "X" -Label the value obtained for "X" Dosage on Hand/Amount on Hand = Dosage desired/amount desired (X)
How to do the dimensional analysis method
-Put the unit of measurement to be calculated to the left of the = sign. (Always express dosages in relation to the medication form or unit of measurement) -Create a fraction with the starting factor, which is the dosage strength available. Match the unit of measure in the numerator with the unit of measure to be calculated -Enter all other factors as fractions. Be sure to include the unit of measure of each quantity. Match each numerator with the previous denominators unit of measure -Cancel the alternate denominator/numerator units of measure. Don't cancel the starting factor's numerator -Solve the equation: -Multiply the numerators -Multiply the denominators -In the resulting fraction, divide the numerator by the demoninator
How to use the basic formula
-Remember the formula -Convert the units to the same measurement system and size- make sure you convert to the measurement you are solving for -Put the data from the problem in the formula -Solve for "X" using the basic formula: D/H x Q = X -Label the answers (mg, tablet, capsule, mL, etc) -Convert to a smaller size unit and the dosage you have on hand
Define pharmacology
A science that studies drugs and how they interact with living systems. ●How chemicals affect the living processes ●Reviews all aspects of drugs including: ○When it was made ○What it is made of ○What it is used for ○Its composition - It's mechanism of action
B.G, 45 y.o female admitted for cellulitis of right lower extremity. She is started on Zosyn 3.375mg IV. She has completed two rounds of antibiotics in which she rings her call light during the third dose. She now complains of a rash to her body, no difficulty breathing, and the rash is itchy. What Drug Reaction is occuring?
Allergic Reaction Minor or Severe?
Category B
Animal studies show no fetal risk, human studies not done
What are three calculation methods?
Basic Formula Ratio and Proportion Method Dimensional Analysis Method
Mr. X, a 78 y.o male arrives to your unit. You are reviewing his home medication list with him. He informs you that his Doctor has prescribed Lipitor for him for his cholesterol but he doesn't understand why the Pharmacy gave him atorvastatin instead. What should you do?
Consult the Doctor and have them D/C one of the medications. They are the same med with a different name.
Basic Formula
D/H x Q = X D= desired dose or what the provider has prescribed H= have the dose (strength) available on hand Q= Quantity or unit of measure of the available dose X= the dose to be administered
Dietary Supplement Health and Education Act (DSHEA)
FDA regulates herbs and dietary supplements
How to prevent medication errors...
Medication errors are preventable causes of harm to the patient ●Use a decimal instead of a fraction ○0.5mg NOT 1/2mg ●Number before unit of measure ○2.5mL NOT mL 2.5 ●Lead with a zero ○0.5mg NOT .5mg ●Never trail with a zero ○2mg NOT 2.0mg ●Use a comma with a number greater than 1,000 ○10,000 units NOT 10000 units ●Use metric rules ○mL NOT cc, mg NOT mgs with multiple
You have administered B.G 7.5mg of Norco for her pain in bilateral legs. She complains to you that it is making her nauseous. What drug reaction is occuring?
Side effect
Some drugs do not act on receptors rather ___________ enzymes or hormones.
Stimulate ■I.e antacids or hormones
Define clinical pharmacology
The study of drugs in humans
Each person will react differently to drug- depending on cell function. What is the name of the effect that is used?
Therapeutic effect
If being nauseous is a side effect. What should you do?
Treat the nausea- this is normal.
What do you do if a drug is incompatible with another drug?
You FLUSH the drug
Antagonistic effect
a drug effect that decreases due to another substance in body. ■I.e antibiotics vs. birth control, narcan vs. narcotic
Synergistic effect
a drug effect that increases due to another substance in body ■I.e Alcohol will enhance the effect of narcotics etc
Agonist
binds to a receptor and produce same activity as the receptor
A drug can only change the strength or rate of the cell function but it ...
never will allow it to work outside its original function
Category C
no adequate studies
Category A
no fetal risk during first trimester
What is maximal efficacy?
the largest effect that a drug can produce
Metabolism
○ chemical alteration of the drug in the body- mostly in liver (first-pass effect- not all of drug is metabolised by liver)
Incompatibility
○ combining drugs that can cause adverse chemical reactions ■Many IV medications CANNOT be combined
Absorption
○ site of administration to blood stream (route of drug)
Excretion
○ transport of the drug out of the body- primarily kidney
Trade name is recommended for...
○Anticonvulsants ○Anticoagulants ○Heart failure medications ○Large doses of Aspirin ●Too many names can cause problems
Clinical Pharmacology studies the application of drugs. What are those studies?
○Discovery ○Development- chemical component ○Effects on people
Hospitals can vary depending on state's nurse practice act by...
○Nurses responsibility to understand and comply to policy of facility ○If not compliant- can lead to fines, imprisonment, and possible loss of license
In the drug legislation, the legislation standards focus on
○Safety ○Potency ○Sales ○Distribution ○Efficacy
What are the two biological responses in pharmacodynamics? Explain both of them.
○Systemic-effects whole body- seen in multiple systems i.e narcotics ○Local- effect limited body areas i.e antipruritic lotion for itching
Hospital Facilities complete the following:
○Tracking- accurate dispensing and documentation ○Floor stock- counting completed- some facilities are at change of shift ○Disposal- if controlled substance is "wasted" two license professionals need to witness together and document
What is a drug?
● A substance that positively or negatively alters the physiologic function of the body ○Active chemical present in a medication used to diagnose, prevent, or treat a disease.
The FDA- U.S. Food and Drug administration
● mandates all medications undergo safety testing before released to public
generic name
● not capitalized and often contains a suffix or prefix that helps to identify the drug class. ○Beta blockers- prescribed for cardiac conditions and end in "olol"
Define nonprescription. Provide an example of a nonprescription and factors that can affect it.
● not prescribed by health care provider, does not need authorization. ○Over the counter (OTC) medications ○Patients need education on proper use- can be abused ○Vitamins & Herbal therapy: monitor for use- are they the same as prescription? ■Can cause toxic reactions
Define prescription
● require legal prescription from health care provider
What is medication?
● specifically administered for therapeutic effect on physiologic function ○Medications prevent, improve, or reduce the symptoms of health conditions
What does the medication names mean?
●Chemical name: describes the elements of the medication's molecular structure ●Official name: assigned by the U.S. Adopted Names Council, which is simpler than the chemical name ●generic name ●Trade name (brand name):
How do we identify a drug?
●Classified by similar effects and actions on the body ○Structure- the drugs mechanism of action- what do we want to accomplish? ○Therapeutic use- what the drug is primarily used for? ●Pharmacokinetics ●Pharmacodynamics ●Chemical structure
Hospital policies and protocols
●Completed in compliance with federal, state, and local regulations
What is our job as RNs?
●Ensure patient safety ●Collect patient history ●Collect a medication history ●Perform a complete physical exam ●Identify side effects of drugs ●Monitor lab values for peak and trough levels- report if abnormal ●Monitor therapeutic ranges ●Refer to drug references ●Educate patients: diet, supplements, pharmacy use ●Assess cultural considerations ●Monitor clinical factors ●Be aware of "Black box warning" - serious or life-threatening risks
Basic units of the metric system
●Grams- units of solids based on weight (G,g) ●Liters- units of volume (L) ●Meters- units of length (M) ●Kilograms (kg)- used for patients weight- some drugs are weight based (mg/kg) ●Milligrams (mg)- 0.001grams- used for solids or solids dissolved in liquid (IV meds)(3 spaces to left) ●Micrograms(mcg)-0.000001grams (6 spaces to left) ●Milliliters (mL)- 0.001 Liter-used for liquids (3 spaces to left)
