Chapter 4: Pharmacokinetics

Chapter 4: Pharmacokinetics

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

1. The nurse has just administered diphenhydramine (Benadryl) and morphine sulfate to a patient. An hour has passed, and the nurse is checking on the patient. The patient asks the nurse why he feels so drowsy. The nurse’s best response would be

a.	“Both of these drugs pass the blood-brain barrier, resulting in sedation.”
b.	“Both of these drugs cause toxicity, leading to sedation.”
c.	“Your drowsiness is a result of an adverse drug reaction (ADR).”
d.	“Both of these drugs act as competitive antagonists and lead to sedation.”

 

 

ANS:   A

Both diphenhydramine and morphine sulfate act by depressing the central nervous system, leading to sedation.

These drugs do not lead to toxicity unless given in excessive doses.

Sedation is an expected side effect of these medications, not an adverse reaction.

These drugs are not competitive antagonists, but they do act on the central nervous system.

 

DIF:    Cognitive Level: Analysis                  REF:    pp. 35-36

TOP:    Nursing Process: Assessment

MSC:   NCLEX Client Needs Category: Physiological Integrity: Pharmacological and Parenteral Therapies

 

2. Two nurses are discussing drugs that are affected by the first-pass effect. The nurses understand that a prime example of a drug affected by the first-pass effect is _____ given _____.

a.	morphine; intravenously
b.	nitroglycerin; sublingually
c.	insulin; sublingually
d.	nitroglycerin; orally

 

 

ANS:   D

Nitroglycerin given orally is subject to the first-pass effect because most of it is destroyed by the liver; therefore, this medication should not be given orally.

An intravenous medication cannot be subject to the first-pass effect.

Nitroglycerin given sublingually is not subject to the first-pass effect, therefore the most effective route for administration of nitroglycerin is the sublingual route.

A drug given sublingually is not subject to the first-pass effect.

 

DIF:    Cognitive Level: Application             REF:    p. 39

TOP:    Nursing Process: Assessment

MSC:   NCLEX Client Needs Category: Physiological Integrity: Pharmacological and Parenteral Therapies

 

3. A nurse administers warfarin (Coumadin) to a patient who is concurrently taking drug X, which also is highly protein bound. The nurse would anticipate that drug X will act at the receptor site as a

a.	competitive agonist.
b.	sympathomimetic.
c.	competitive antagonist.
d.	parasympathomimetic.

 

 

ANS:   C

Because both drugs are highly protein bound, they will be competing for the same receptor site; they therefore are competitive antagonists, which increases the risk of toxicity.

Competitive agonists are drugs that compete for the same receptor site but do not potentiate the effects of the drugs.

A sympathomimetic effect mimics the effects of the sympathetic nervous system.

A parasympathomimetic effect mimics the effects of the PNS.

 

DIF:    Cognitive Level: Analysis                  REF:    p. 37

TOP:    Nursing Process: Diagnosis

MSC:   NCLEX Client Needs Category: Physiological Integrity: Pharmacological and Parenteral Therapies

 

4. The nurse is caring for a patient with a cold who presents to the emergency department after having taken diphenhydramine (Benadryl), a glass of wine, and four shots of whiskey to “kill” the cold. The nurse should observe the patient for apparent signs of

a.	vomiting and gastrointestinal upset.
b.	central nervous system depression.
c.	dryness in the oral mucosa.
d.	mydriasis.

 

 

ANS:   B

CNS depression is a resultant drug-to-drug interaction for a patient taking diphenhydramine and alcohol, because both are central nervous system depressants.

Mixing diphenhydramine, wine, and whiskey may or may not cause vomiting and gastrointestinal upset.

Dryness of the oral mucosa is not significant when a patient has mixed diphenhydramine, wine, and whiskey.

Miosis (constricted pupils) rather than mydriasis (dilated pupils) could possibly be expected when diphenhydramine, wine, and whiskey are mixed.

 

DIF:    Cognitive Level: Analysis                  REF:    pp. 35-36

TOP:    Nursing Process: Assessment

MSC:   NCLEX Client Needs Category: Physiological Integrity: Reduction of Risk Potential