Chapter 3- Drug Action Across The Life Span Flashcards
Define genetics
The study of how living organisms inherit the characteristics or traits of their ancestors
True or False
A person’s genetic composition serves as the basic foundation for all drug responses and their duration of action in the body through out the person’s lifetime
True
What are important inheritances from genetics?
Metabolic pathways and susceptibility to illness
Define genome
The complete package of genetic coding of an organism
How many chromosomes are donated by the biologic mother and father?
23 each
A large molecule named Deoxyribonucleic or DNA carries?
Genetic information
Genes are
Instructions that are contained in segments of DNA
Define polymorphism
Naturally occurring variations in the structures of genes and the instructions that they give the organism
The study of how drug response may vary according to Inherited differences is known as
Pharmacogenetics
What factors affect ADME?
Age, gender, organ function, drug therapy, and drug interactions
Less than 38 weeks of gestation
Premature
0 to 1 month
Newborn or neonate
One to 24 months
Infant or toddler
3 to 5 years
Young Child
6 to 12 years
Older child
13 to 18 years
Adolescents
19 to 54 years
Adult
55 to 64 years
Older adult
65 to 74 years
Elderly
75 to 84 years
The aged
85 years or older
The very old
True or False
Man and woman do not respond to medications differently
False
Gender specific medicine is
Science that studies differences in the normal function of man and woman and how people of each gender perceive and experienced disease
How can the absorption of medicines given by IM may be affected?
Differences in muscle mass, blood flow to muscles, and muscle activity in patients who are bedridden
Why are topical administration usually more effective in infants
The outer layer of skin is not fully developed so this skin is more hydrated and water-soluble drugs are absorbed more readily
Why do babies get diaper rash?
Plastic acts as an occlusive dressing that increase hydration of the skin. Water soluble drugs are absorbed more readily in hydrated skin
True or False
Inflammation increases the amount of drug absorbed
True
True or False?
Time release tablets, enteric-coated tablet, and sublingual tablets should not be crushed because it will increase absorption and potential for toxicity
True
Chewable tablets should not be given to everyone even children who
Have loose teeth
What factors influenced GI absorption?
Gastric pH, gastric emptying time, motility of the G.I. tract, enzymatic activity, blood flow of the mucous lining of the stomach and intestines, permeability and maturation of mucosal membranes and concurrent disease process
What is the pH for a premature infant?
A pH of 6 to 8
What is the pH of Full stomach
Five
True or False
A woman’s stomach empty more slowly than a man
True
What is the total body water content of a preterm infant?
83%
What is the total body water content Of an adult man?
60%
What is the total body water content of an older adult person?
50%
Complete the sentence
As we age, lean body mass and total body water..
Decrease
Complete this sentence
As we age, total fat content…
Increases
What are some drugs that are highly fat soluble?
Antidepressants, phenothiazines, benzodiazepines, and calcium channel blockers
Complete the sentence
Drugs that are highly fat-soluble….
Require a longer onset of action and accumulate in tissue, prolonging their action and increasing the potential for toxicity
Give two examples of water-soluble drugs
Ethanol and aminoglycoside antibiotics
Why must highly fat-soluble medicines be given in smaller dosage to low birth weight infants?
Because there is less fat tissue to bind the drug, leaving more drug to be active at receptor sites
What disease states can lower albumin levels?
Reno failure, malnutrition, and cirrhosis
Define drug metabolism
The process whereby the body and activates medicine
What are the major pathways to drug metabolism
Enzyme systems that is found primarily in the liver
How does age affect the liver?
Liver weight, the number of functioning hepatic cells and hepatic bloodflow decreases with age
True or False
There are specific laboratory tests that are available for measuring liver function
False
Erythromycin, prednisolone, verapamil, and diazepam metabolize faster in
Women
What are the primary routes of drug excretion?
The renal tubes into the urine and the G.I. tract into the feces
Define drug excretion
When the metabolites of drug and sometimes the active drug itself are eventually excreted from the body
List other minor routes of excretion
Evaporation through the skin, exhalation from the lungs, and secretion into the saliva and breastmilk
What happens to the kidneys as the body ages?
Decreased renal bloodflow caused by arteriosclerosis and reduced cardiac output, a loss of glomeruli, and decreased tubular function and concentrating ability
Define therapeutic drug monitoring
The measurement of a drugs concentration and biological fluids to correlate the dosage administered and the level of medicine in the body with the pharmacologic response
Which assay is commonly used for drug concentration?
Blood serum samples
Why is therapeutic drug monitoring and essential in neonates, infants and children?
To ensure that the drugs are within an appropriate therapeutic range
What must be adjusted to ensure therapeutic serum concentration
Dosage and frequency of administration
List all the conditions that therapeutic drug monitoring is routine
Epilepsy, dysrhythmias, heart failure, and antimicrobal therapy
To prevent toxicities and ensure that dosages are adequate to provide appropriate therapeutic levels
When would blood levels of drugs be measured?
If toxicity is suspected
How does one test the blood level of a drug for therapeutic monitoring?
One sample is drawn immediately before the next dose is to be administered to obtain the trough. Another is drawn 20 minutes after the medicine has been administered via IV or 60 minutes after the medicine have been administered orally to obtain the peak
List examples of parameters
Expected therapeutic actions, expected side effects, reportable adverse effects, probable drug interactions, laboratory results, vital signs
What is the nurse expected to do when a peak and trough for an medication has been ordered
The nurse must check the laboratory results in a timely manner and make sure that the prescriber is notified of the laboratory results
Children are susceptible to dehydration from
Fever vomiting and diarrhea
Why is it difficult to assess the therapeutic response to medicines administered to neonates, infants and young children?
These patients are often nonverbal or cannot tell us where it hurts
Define polypharmacy
Multi drug therapy
Explain trough and peak
Trough is before the next dose peak is after the med is given
List the six rights
1) Right dose
2) Right drug
3) Right person
4) Right documentation
5) Right time
6) Right route
Two medications that have a narrow therapeutic window
Digoxin and gentamycin
What are the parameters for warfarin
Must know PT and INR
What is the INR for warfarin
2 to 3
What is the parameter for Heparin?
PTT
What is the PTT for heparin?
1 1/2 to 2 1/2 times control
Examples of renal function tests
BUN, Creatinine, and GFR
What are the parameters for Lovenox
Platelets. Hold if less than 100,000
If gastric emptying time increases what happens to the speed of absorption of a drug
The faster the empty time the less time the drug has to be absorbed therefore drug absorption is decreased
List accurate methods of measuring oral liquid medication
Medicine cups, droppers provided with a specific medication, or oral syringes to measure liquid forms of oral medications accurately
Fill in the blank
The younger the individual the ____ the percentage of the total body water
Higher
Fill in the blank
Off label use of medication is____?
Legal
Fill in the blank
Lipid soluble drugs have an affinity for fat tissue in the body and will often have a ___ half-life
Longer
What is the safest method of initiating newly prescribed medications to a geriatric patient?
Drug dose should be initiated at 1/3 to 1/2 the normal adult dose. Therapeutic drug monitoring should be completed
