Study Guide Questions-Exam 1
1. What factors are associated with clinical judgment when prescribing medications?
Factors involved when prescribing medications including taking into account:
Patient’s environment, determination of medical/nursing diagnoses, potential
alternative therapies, knowledge of drug chosen and disease its designed to treat
**Federal/State laws, state boards regulate state regulations, thorough assessment of
patient during physical, obtain diagnostics, find suitable medication, follow-up with
patient (see if patient is responding to therapy or not), prescribe the least expensive
and least likely to cause adverse effects and is the least invasive, non-pharmacologic
interventions (allergies, contraindications, correct dosage), have the patient already
tried anything beforehand (drug interactions, right route of medication),
genomics/genetics**
2. What are the criteria for choosing an effective drug?
Clear indication for drug? Drugs effective in treating disorder? Goal of therapy with
this drug? What conditions a drug is not meeting its goal and a different therapy is
needed? Unnecessary duplications? Would over-the-counter drugs be a better option
than prescription drugs? Cost effective?
**Is therapy likely to work? What is your goal for the patient? Choose the right
drug, is there any non-pharmacologic adjunct therapies that might help the patient?
Patient must be informed about disease process, instructions on how to take
medications, contraindications, Patient needs to be followed-up on a regular basis,
drug cost**
3. Describe the process of passive diffusion and the factors that affect a drug’s ability
to passively diffuse across a cell membrane.
Passive diffusion occurs when drugs are able to cross through a semi permeable
biological barrier such as a cell membrane. Diffusion will depend on the
concentration on both sides of the barrier, in which passive diffusion will proceed
until the concentration of the drug is uniform or unionized on both sides of the
barrier.
**No energy required, smaller, non-charged, lipid soluble drugs**
4. How does hypoalbuminemia affect the process of prescribing?
Binding to proteins is the basis of drug interaction. Most drugs are protein binding,
and plasma binding protects drugs from being metabolized or excreted, therefore can
, remain in the body for longer periods of time. In patients with hypoalbuminemia, the
amount of unbound drugs will increase and metabolize quickly.
**More free drugs, may need to decrease dose of medication**
5. Explain first pass metabolism.
First pass metabolism refers to when a drug gets metabolized in a specific location of
the body where the drug become reduced in concentration upon reaching site of
action or systemic circulation. In most cases, the liver is the first organ drugs will
encounter upon oral administration.
**Will need higher doses to overcome this phenomenon or different routes**
6. What factors affect a drug’s absorption?
-Bioavailability –Presystemic metabolism –Gastric emptying time –
Concentration gradient –Absorptive surface area
**pH, drug solubility, routes of administration, conditions of sites of administration,
formulation of drug**
7. Describe drug metabolism and the role of the isoenzymes of the cytochrome P450
system.
Drug metabolism in both the GI tract and liver is affected by nutrient intake. Depending
on diet, specifically, low carbs, high protein diet may increase drug-metabolizing
enzymes. Also increase intake of antioxidant cruciferous foods can increase the activity
of these enzymes, such as cytochrome P450. Cytochrome P450 (CYP450) is a major
enzyme group responsible for metabolizing foreign chemicals in the body.
**Convert drugs into water soluble, then can be excreted by kidneys, sites of
metabolism: Liver, intestinal walls, lungs, kidneys, & plasma, sites of excretion: Liver &
Kidneys**
8. Define drug affinity.
Drug affinity Drug’s “attraction” or chemical forces that causes a substance to bind
to certain receptors.
9. Define drug efficacy.
Drug efficacy Refers to a drugs ability to effectively activate a receptor once it is
bound to it. This information tells us how good a drug is at producing a desired effects
** Potency: The amount/concentration of a drug, more potency will require less amount
of a drug to achieve desired effect; Efficacy: Judges therapeutic effectiveness of drug**