Chapter 4 Pharmcognetics Flashcards
Study of how a patient’s genomes affect drug
response
Pharmacogenetics
Patients who benefit
most from pharmacogenetics
taking multiple prescription
drugs, Those not responding to current therapy, Those having adverse drug reaction, black box warning
Helps decrease drug reactions
Pharmacogenetics
is the body’s physiologic response to changes in drug concentration at the site of action.
dose-response relationship
is defined as the drug’s ability to produce the desired result.
Efficacy
refers to the amount of drug needed to elicit a specific physiologic response to the drug.
Potency
drug with high potency (e.g., morphine) produces significant therapeutic responses at
low concentrations
drug with low potency (e.g., meperidine) produces _______________ at low concentration
minimal therapeutic responses
Drug’s minimum effective concentration (MEC) is the plasma drug level below which therapeutic effects will
not occur
Oral drugs reach peak in
2 to 3 hours
Intramuscular drugs reach peak in
2 to 4 hours
Intravenous drugs reach peak in
30 to 60 minutes
of action is the length of time the drug exerts a therapeutic effect.
Duration
When monitoring for therapeutic response in a patient prescribed a new drug, it is important for the nurse to understand it takes about___________ half-lives for a drug to reach steady state.
4
Drug-binding sites are primarily on
proteins, glycoproteins, proteolipids, and enzymes.
domain for drug binding is on the cell surface. The drug activates the enzyme inside the cell, and a response is initiated
The ligand-binding
The three components to the G protein-coupled receptor are
(1) the receptor, (2) the G protein that binds with guanosine triphosphate (GTP), and (3) the effector
found in the cell nucleus on DNA, not on the surface.
transcription factors
When drugs interact with a specific receptor and maintain focus on a specific process, the action of the drug is limited because it does not affect multiple receptors.
selective action
If a drug interacts with several receptors
nonselective
Drugs that exert their effect across many tissues or organs. An example of this drug is atropine.
relatively non-selective
Drugs that exert a singular effect on a specific target tissue or organ. An example of this is the nonsteroidal anti-inflammatory drugs (NSAIDs), which include aspirin and ibuprofen.
relatively selective drug
Drugs that exert their effect on a single organ or organ system. An example of a this is digoxin, which effects electrolyte channels in the heart the heart, resulting in a decrease in heart rate
highly selective drug
neutralize gastric acidity by direct chemical interaction with stomach acid.
Antacids
Ethyl alcohol precipitates bacterial proteins.
Antiseptics
work directly on target organs.
Hormones
Magnesium sulfate acts by retaining water in the intestinal lumen through an osmotic effect.
Saline laxatives
These agents prevent toxicity by forming complexes with heavy metals.
Chelating agents
Cell membrane channel opens, and ions flow into and out of the cells.
Cell membrane–embedded enzymes
Which type of drug can mimic or block the actions of receptors?
Partial agonists
When two drugs are administered in combination, occasionally the response is increased beyond what either could produce alone.
additive effect.
When two or more drugs are given together, one drug can have a this on another. This means the therapeutic effect is substantially greater than that of either drug alone.
synergistic effect
Some antibiotics have an enzyme inhibitor added to the drug to _________ the therapeutic effect.
potentiate
When drugs with ___________________are administered together, one drug reduces or blocks the effect of the other.
antagonistic effects
Which drug may cause toxicity when taken with grapefruit juice?
Cyclosporine
For example, St. John’s wort, an herbal medication, reduces the effectiveness of many drugs, including
digoxin, warfarin, and oral contraceptives.
may result from decreased drug clearance in patients with impaired kidney or liver function or from drug-drug interactions
Dose-related adverse effects
are not dose-related and usually require prior exposure.
Allergic adverse effects
are unexpected adverse effects that are not dose-related or allergic. Genetically determined abnormal response to a drug
Idiosyncratic adverse effects
is an effect that is opposite of the intended drug response.
paradoxical effect
occurs when drug levels exceed the therapeutic range
Drug toxicity
Drugs with narrow TIs require close monitoring to ensure patient safety
aminoglycosides, warfarin, digoxin, lithium, phenytoin
Administering a diuretic and beta blocker for hypertension
Additive
Using two cytotoxic drugs to treat cancer at lower doses than if given alone
Synergistic
Adding a bacterial enzyme inhibitor to an antibiotic
Potentiation
Giving naloxone to block harmful effects of morphine overdose
Antagonistic
After administering lorazepam to an older adult patient with restlessness and crying, the patient becomes hostile and aggressive and has angry outbursts and psychomotor agitation. Which type of adverse drug effect is the patient experiencing?
Paradoxical reaction
