z. Exam 1 Concepts Flashcards
Yearly Process for FDA Approval
0-4 Years: Computer models and animal studies
4: Healthy human volunteers (male, young, no previous medical conditions)
6ish: Target population
9: Market, expanded to elderly, liver/kidney
20 years: Patents and generics
Lab Testing in Vitro
In test tubes or dishes
Lab Testing in Vivo
On living organisms
Vitro: the ‘t’ is for trial or laboratory setting
Medication Death: Misfeasance
Negligence - wrong drug or dose given
“missed the mark”
Medication Death: Nonfeasance
Omission- not giving prescribed medication
Medication Death: Malfeasance
Giving the correct dose but through wrong route
Pharmacogenetics
Variations of the predicted drug response due to patients individual genetic factors
Biologic Variations (Asian/African American)
Asian: Decreased Response to drugs r/t CTP2D6 enzyme
AA: Respond poorly to anti-hypertensives
Disintegration
Stage 1 in physically breaking down a medication
Dissolution
Drug becomes a solution that can cross biologic membrane and available for the body absorb/use
Absorption
Movement of drug particles from the GI tract to the body fluids
Distribution
Drug becomes available to body fluids and tissue
Metabolism
Body (individual cells) inactivates the drug
Excretion
How the body gets rid of the drug (kidney/liver)
Effects on Absorption
- Drug forms, route, GI mucosa’s, food, metabolism
- Absorption is reduced if there are fewer villi in small intestine (r/t disease or surgery)
First pass effect
Medication passes through the liver before it reaches systemic circulation
Bioavailability
What % of the dose reaches the systemic circulation
IV - 100%
IM/SC - 75%-100%
PO - 5%-100%
Rectal - 30% - 100%
Blood brain barrier and its effect on distribution
Only lipid soluble medications are able to pass, making treatment for brain injuries challenging
Drug Classifications for Pregnancy
A, B, C, D, X
Where X is never
Ex Thalidamide
Liver Disease and the effects on metabolism
Since most medications are metabolized by the liver, a damaged liver extends the half life and could lead to toxicity
Main route of excretion
Kidneys
Others: Liver, feces, lungs, saliva, breast milk, sweat
Effects of GFR on excretion
A decreased GFR impairs drug excretion and can lead to accumulation of the drug in the system
Pharmacodynamics
Study of biochemical and physiological effects of drugs (what the drug does to the body)
Pharmacodynamics - Primary effect
Desirable and what the medication is supposed to do
Pharmacodynamics - Secondary effect
Can be desirable or undesirable leads to off-label uses of medications
Maximal Efficacy
Where giving more of a medication will not change its maximal effect
Agonists
Drugs that produce a response and enhance another drug
Antagonists
Drugs that block a response, prevent receptor activation
Ex: Narcan on Opioids
Nonspecific drug effect
Act on multiple same receptors throughout body
Nonselective
Acts on multiple different types of receptors (Epinephrine acts on alpha 1, beta 1, beta 2)
Drug Action - Stimulation/Depression
Narcotics, Amphetamines
Drug’s Action in Body - Replacement
Synthroid, insulin
Drug Action - Inhibition of killing organisms
Antibotics
Drug Action - Irritation
Laxative
Therapeutic Index
Margin of safety of a drug. Between it not working and not having toxic effects
Loading Dose
Larger dose of drug given when first starting new drug
Side Effects
Physiologic effects that are not related to the desired drug effects. Some are desirable some undesirable
Adverse Reactions
Always undesirable and normally severe, must be reported and documented
Patient Genetic Variances in Stable Warfarin Dose
Extensive 4-5 days
Intermediate 8-10 days
Poor metabolizer 12-15 days
Tolerance
Needing more medication to get the same effect
Tachyphylaxis
Rapid decrease in response to drug, where it does not have a therapeutic effect on the patient
Placebo Effect
psychological benefit from a ‘sugar pill’
Teratogens
Cause birth defects
Carcinogens
Cause cancer
Metabolites
End product of metabolism
Placebos
Drugs with no pharmacologic activity
What is an excipient
An inactive ingredient that does not have a pharmacological effect
Ex: dyes, preservatives, binding materials, flavorings
Problems with Excipients
Some have excessive sodium or some may have an allergic or adverse reaction to the excipients
Neurobiology of Addictive Drugs
Many allow for higher levels of dopamine, either by increasing its secretion, or decreasing it absorption
Tolerance
Needing more of a drug or medication to get the same effect
Physical Dependence
When the drug is ceased a person will go into withdrawal syndrome normally with in 24-48 hours
Psychologic Dependence
The drug is associated with a lot of different tasks and activities, many people just feel better when on the the medication
Cue-Induced Craving
Different activities that would cue the patient to reach for the drug again
Withdrawal Syndrome
Groups of signs and symptoms that occurs in a physically dependent person when the drug is stopped
Nicotine - Side effects
cardiovascular stimulation, increase CNS stimulation, tremors, increased alertness and arousal, promotes relaxation and relief of anxiety
How is caffeine related to nicotine, what should you tell patients who are quitting
When decreasing nicotine intake they also need to decrease caffeine
What is a pack year history
One pack a day is a one year history
Two packs a day for a year is a two year history and so on.
If a patient smokes 2 PPD for 30 years they have a 60 pack year history
Caffeine OD treatment
Reduce hypertension, dysthymias and other side effects while you wait for the drug to leave the system
Acetaldehyde Syndrome
The accumulation of acetaldehyde r/t drinking on antebuse causes N/V, CP and hypotension
Barbiturates, Benzos and their relation to tolerance
While the patient may not feel the same effects there is no developed tolerance for respiratory depression.
Signs of opioid overdose
Pinpoint pupils, clammy skin, depressed respiration, coma or death
Drug Interaction
Altered of modified actions or effect of a drug as a result of an interaction with another drug
Adverse Drug Reaction
Undesirable drug effect that ranges from mild effects to severe toxicity (anaphylaxis or hypersensitivity reactions)
Drug Incompatibility
Chemical or physical reaction that occurs among two or more drugs
Drug interactions: Physiological Changes with Absorption
Changes gastric emptying times (Laxatives), changes PH (antacids, asprin), forms different drug complexes (dairy products and ciprofloxacin)
Drug interactions: Changes with Distribution
Competition for proteins binding sites (warfarin and glyburide both protein bound)
Drug interactions: Changes with Metabolism
Inhibition or induction of liver enzymes (tagament inhibits the metabolism of theophylline - causing seizures and arrhythmias)
Drug interactions: Changes with Excretion
Changes in the rate of excretion (lasix decreases K+ levels)
Additive Drug Effect
1+1 = 2
Synergistic drug effect (Potentiation)
1+1 > 2
Antagonistic drug effect
1 + (-1) = 0
Drug/Food interactions
Can increase, decrease or delay absorption, bind with drugs, some specifics may need to be avoided
Ex: Grapefruit juice effect
Creatinine Clearance, factors effecting
Measures GFR and will tell us how well the kidneys are working. Compare’s creatinine level in the blood with level in urine
Lower values expected in patients with decreased muscle mass
Peaks and Troughs
Peak - highest drug concentration
Trough - lowest concentration
Used to evaluate the appropriate dosage of many medications due to a narrow therapeutic range
Main meds: Digoxin, Vancomycin
Drug Induced photosensitivity
patients should avoid the sun when on sulfa and bactrim antibotics
Importance of OTC medication
Can cause interactions, including inactive ingredients, make sure to ask patients about OTC
Polypharmacy
Confusion with the use of herbs, OTCs and multiple providers
Many tend to keep discontinued medications and share with neighbors and friends
ASK ABOUT OVER THE COUNTER
Changes to the geriatric pharmacodynamics/pharmacokinetics
Lack of affinity to receptors, ages changes r/t CNS changes, less drug receptors
in general patients are more or less sensitive to medications
Geriatric effects on Hypnotics
Drugs with short to intermediate half life should be used
Drug examples: ramelteon (rozerem) diazapam (valium) and lorazepam (ativan)
Geriatric effects on Diuretics and antihypertensives
Those on diuretics should be closely monitored for electrolytes since they are at risk for imbalances. Alpha1 blockers and Alpha 2 agonists are infrequently prescribed because of orthostatic hypotension
Geriatric effects on Cardiac Glycosides (Dig)
Most of digoxin is eliminated by the kidneys, so a decline in kidney function can cause digoxin accumulation, which can cause bradycardia. Digoxin should not be given to any patient with a pulse less than 60 beats per minute
Geriatric effects on anticoagulants
Decreased serum albumin, risk for falls, increased risk for hemorrhage
Assess PT/INR and signs of bleeding
Geriatric effects on Antibacterials
Aminoglycosides (-mycin) are not frequently prescribed due to the excretion in the urine
Geriatric effects on GI drugs
Cimetidine (tagament) is not a good choice because of the confusion, as well as the
-prazoles because of C. Diff potential and fracture potential
Elderly patients also tend to abuse laxatives that cause electrolyte imbalances and interfere with absorption of other meds
Geriatric effects on Antidepressants
The dosage is 30-50% less then the dosage prescribed for young adults
Tricyclic antidepressants can have increased SE: dry mouth, tachycardia, constipation, urinary retention and can contribute to narrow-angle glaucoma
Patients should be described SNRI’s and SSRI’s with a shorter half life
Geriatric effects on Opioids
More dose related adverse reactions (hypotension and respiratory depression)
More constipation
Special Nursing Coniderations for the Elderly to make sure information is understood
Eye glasses clean, hearing aids charged and in place, clear tones, face to face speaking, large print and bold colors, review all medications, simple dosage schedule (more at once, not spread out)
Encourage the communication of and side effects
Changes to pediatric pharmacokinetics: Absorption
Age, health status, underlying disease, hydration, route of administration, gastric acidity, enzyme levels, peripheral perfusion, effectiveness of circulation, children’s skin is thinner and more porous (faster absorption for topicals)
Changes to pediatric pharmacokinetics: Distribution
Body fluid composition (neonates and infants are 70% water, require a higher dosage of water soluble medication)
Body tissue composition (neonates and infants have less body fat and require lower doses of fat-soluble medications)
Neonates/infants have less albumin and fewer protein receptor sites (require less protein-bound medication)
Immature BBB at birth and makes them sensitive to drugs interacting on CNS
Changes to pediatric pharmacokinetics: Metabolism
Children have a higher metabolic rate
Neonates (under 3 mo) are sensitive to drug eliminated by hepatic metabolism, need lower dosages
By 3 mo infants have adequate drug metabolizing enzymes
Changes to pediatric pharmacokinetics: Excretion
Kidneys: Infants have decreased renal blood flow, GFR and renal tubular function
Pediatric Nursing Implications
Watch for allergies, calculate safe dosages (body weight, body surface areas, height or age) Trust assessment skills and stop medications if you see s&sx of toxicity stop medication
Safe pediatric med admin
Atraumatic cares and maintaining safety with minimal restraint, mix local anesthetics ex LET (lidocaine, epinephrine and tetracaine) and distraction for pain and anxiety control
Preferred IM/SC/IV sites for peds
Ventrogluteal or vastus lateralis (deltoid is underdeveloped)
SC in leg or upper arm over abdomen
IV: fluid overload happens quickly
Current parent recommendation for OTC cough and cold treatment for peds
no longer recommended to swap ibuprofen and acetaminophen because of the complication and risk for OD
Treatment for cough in children
Honey most effective (not for use in children under 1)
Child Med Safety
Do not round up, no leading or trailing 0’s, Label the unit of measurement
