Module 2 Kelsey Pharmacology Chapter 11 Practice Questions Flashcards
An individual with a genetic polymorphism causing the person to be a poor (slow) metabolizer of a specific drug compared with an individual without the polymorphism may have:
A) a greater risk of toxicity with the same dose of the drug.
B) difficulty maintaining a therapeutic drug level.
C) increased conversion of a prodrug to the active metabolite.
D) increased risk for hypersensitivity reactions to drugs.
A) a greater risk of toxicity with the same dose of the drug.
Individuals with a genetic polymorphism that affects the function of CYP450 enzymes, causing them to be poor (slow) metabolizers of a drug, may have significantly elevated plasma concentrations of the drug and greater risk of toxicity with the same dose of the drug compared to those without the polymorphism. Poor (slow) metabolizers may not be able to convert a prodrug to an active metabolite.
Which of the following statements in regard to pharmacokinetic changes during pregnancy is correct?
A) First-pass metabolism of drugs is increased during pregnancy because of increased blood flow through the maternal liver.
B) Drug elimination may be faster because of an increase in the GFR.
C) Higher levels of drug protein binding may occur with decreased albumin levels.
D) Drug absorption may be decreased because of increased plasma volume.
B) Drug elimination may be faster because of an increase in the GFR.
The GFR begins increasing early in pregnancy, peaks at 9 to 16 weeks, and plateaus at a rate approximately 50% above the pre-pregnancy rate at 34 to 36 weeks. An increased GFR can result in faster elimination of some drugs, resulting in a lower serum concentration during pregnancy.
The term used to describe the propensity of a drug to bind with a specific receptor is:
A) affinity.
B) bioavailability.
C) efficacy.
D) potency.
A) affinity.
Affinity is the propensity of a drug to bind itself to a given receptor site. Efficacy is the ability of the drug to initiate biologic activity as a result of such binding.
The term used to describe a drug that initiates a physiologic response when it is bound to a drug receptor is:
A) agonist.
B) antagonist.
C) metabolite.
D) prodrug.
A) agonist.
One mechanism of drug effect is through drug–receptor interaction. A receptor can be a cellular protein, enzyme, or membrane that, when bound to a drug, initiates a physiologic response or blocks a response that the receptor normally stimulates. The term agonist refers to a drug that, when combined with the receptor, stimulates a physiologic response. The term antagonist refers to a drug that, when combined with the receptor, blocks the response.
For a pregnant person with diabetes and at risk for preterm birth who has completed a single course of betamethasone, which of the following effects should be anticipated?
A) Elevated blood pressure
B) Elevated heart rate
C) Increased insulin dosage
D) Increased risk of infection
C) Increased insulin dosage
A maternal side effect of corticosteroids is increased insulin requirements in those individuals with diabetes. This point should be included in anticipatory guidance given to patients.
Which of the following pharmacokinetic changes could decrease the effect of a medication?
A) Decrease in plasma protein binding
B) Increase in hepatic first-pass effect
C) Increase in enterohepatic recirculation
D) Increase in bioavailability
B) Increase in hepatic first-pass effect
Orally administered drugs go from the GI tract through the portal system to the liver before entering the general circulation. Some metabolism (chemical inactivation) of drug may occur as it taken up by hepatic microsomal enzymes.
Instructions for a patient for whom you are prescribing an oral bisphosphonate should include:
A) take the medication in the evening at bedtime.
B) take the medication with an antacid to avoid GI irritation.
C) take the medication with 8 ounces of plain water.
D) take the medication with orange juice to enhance its absorption.
C) take the medication with 8 ounces of plain water.
Acyclovir is not effective in eliminating latent herpes virus because it:
A) has a short elimination half-life of 3 to 4 hours.
B) has only a 15% to 20% bioavailability.
C) is a prodrug that is converted to active form by first-pass metabolism.
D) is effective only against rapidly replicating herpes virus.
D) is effective only against rapidly replicating herpes virus.
Acyclovir is selectively activated in infected cells and works by inhibiting viral DNA synthesis. Because it is effective only against rapidly replicating herpes virus, it is not effective in eliminating latent herpes virus.
The use of nitrous oxide in labor is contraindicated in an individual with:
A) a history of vitamin B12 deficiency.
B) gestational diabetes.
C) chronic obstructive pulmonary disease.
D) a previously placed epidural.
C) chronic obstructive pulmonary disease.
A pulmonary condition such as chronic obstructive pulmonary disease is a contraindication for nitrous oxide, because this drug alters the hypoxic drive. As nitrous oxide is delivered with high concentrations of oxygen, this combination weakens the ventilatory response to hypoxia, which is dangerous in someone who is already compromised.
A patient taking metronidazole and cimetidine at the same time is at increased risk for:
A) bothersome side effects from metronidazole.
B) decreased effectiveness of cimetidine.
C) renal impairment.
D) a severe disulfiram-type reaction.
A) bothersome side effects from metronidazole.
Cimetidine can decrease the hepatic metabolism of metronidazole and increase its serum levels.
Which of the following medications is considered a prodrug that is metabolized to a more active form by enzymes in the liver?
A) Alendronate
B) Atorvastatin
C) Oxybutynin
D) Tamoxifen
D) Tamoxifen
Which of the following is a reason to draw and assess a magnesium level in a pregnant person with preeclampsia who is on magnesium sulfate for seizure prophylaxis? The patient reports:
A) a headache.
B) difficulty breathing.
C) increased appetite.
D) severe urticaria.
B) difficulty breathing.
Magnesium sulfate can have depressive effects on the maternal CNS. Toxicity can occur if serum magnesium levels are too high (> 7 mEq/L). If the patient experiences shortness of breathing, toxicity should be considered and a serum magnesium level drawn, as calcium gluconate may be given as an antidote.
A common side effect of oral oxybutynin is:
A) dry mouth.
B) nausea.
C) increased sweating.
D) muscle pain.
A) dry mouth.
The anticholinergic action of oxybutynin may cause side effects such as dry mouth, constipation, urinary retention, blurred vision, impaired sweating, and drowsiness.
Oxytocin is effective in the management of postpartum hemorrhage due to its:
A) diuretic effects.
B) expulsive effects.
C) fibrinolytic effects.
D) uterotonic effects.
D) uterotonic effects.
The uterotonic effects of oxytocin cause contractility in the myometrium, which limits bleeding from vessels in the endometrium. Thus this agent is a first-line treatment in the management of immediate postpartum hemorrhage.
Fluconazole is effective in a one-time dose because it:
A) is rapidly absorbed in the GI tract.
B) has a bioavailability greater than 90%.
C) is widely distributed into body tissues and fluids.
D) has a mean elimination half-life of 30 hours.
D) has a mean elimination half-life of 30 hours.
The half-life is the time it takes for plasma concentration of a drug to decrease by 50%; it is used to determine both the time required to reach a steady state and the dosage interval. Based on a half-life of 30 hours, the recommended dose of fluconazole for uncomplicated vulvovaginal candidiasis is a 150-mg oral tablet taken in a single dose.
