Chapter 12 Basic Principles of Neuropharmacology

Chapter 12: Basic Principles of Neuropharmacology Test Bank MULTIPLE CHOICE 1. A patient receives morphine and shows signs of toxicity. The prescriber orders naloxone [Narcan] to reverse the effects of the morphine. The nurse understands that the naloxone reverses morphine toxicity by which action on morphine receptor sites? a. Blocking transmitter reuptake b. Inhibiting transmitter release c. Interfering with transmitter storage d. Preventing activation of receptors ANS: D Morphine and its antagonist, naloxone, act directly at the same receptors. Morphine causes activation, and naloxone prevents activation. Neither morphine nor naloxone acts to alter transmitter reuptake, release, or storage. PTS: 1 DIF: Cognitive Level: Comprehension REF: pp. 98-99 TOP: Nursing Process: Diagnosis MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 2. A nurse is teaching a group of nursing students about neuropharmacology. Which statement by a student about peripheral nervous system (PNS) drugs indicates a need for further teaching? a. “Drugs affecting axonal conduction have a variety of uses.” b. “Drugs that alter synaptic transmission can be highly selective.” c. “Many PNS drugs act by altering synaptic transmission.” d. “These drugs work by influencing receptor activity.” ANS: A Local anesthetics are drugs that work by altering axonal conduction. Any drug affecting axonal conduction would be nonselective, because axonal conduction of impulses is essentially the same in all neurons. In contrast, drugs that affect synaptic transmission can be highly selective, because each transmitter has different effects on receptor sites. Most PNS drugs work on synaptic transmission processes. Through their effects on transmitters, they influence receptor activity. PTS: 1 DIF: Cognitive Level: Analysis REF: pp. 96-97 TOP: Nursing Process: Evaluation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 3. A nurse is preparing to administer a medication and learns that it is a nonselective agonist drug. What does the nurse understand about this drug? a. It directly activates receptors to affect many physiologic processes. b. It directly activates receptors to affect a specific physiologic process. c. It prevents receptor activation to affect many physiologic processes. d. It prevents receptor activation to affect a specific physiologic processes. ANS: A Drugs that directly activate receptors are called agonists, so this drug will directly activate the receptor site. Drugs that are nonselective activate a variety of receptor sites. A selective agonist would directly activate specific receptors to affect a specific process. An antagonist would prevent receptor activation. PTS: 1 DIF: Cognitive Level: Analysis REF: pp. 98-99 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 4. A nurse is administering drug X to a patient. The drug information states that the drug acts by activating receptors in the peripheral nervous system by increasing transmitter synthesis. The nurse understands that the effect of this drug is to: a. activate axonal conduction. b. enhance transmitter storage. c. increase receptor activation. d. synthesize supertransmitters. ANS: C Drugs that increase transmitter synthesis increase receptor activation. Other drugs that alter transmitter synthesis can decrease synthesis and would cause decreased receptor activation. Drugs that affect transmitter production do not exert their effects on axonal conduction. The amount of transmitter produced does not directly affect transmitter storage. Some drugs that alter transmitter synthesis cause the synthesis of transmitter molecules that are more effective than the transmitter itself. PTS: 1 DIF: Cognitive Level: Application REF: pp. 96-97 TOP: Nursing Process: Implementation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 5. A nurse learns about a drug that interferes with transmitter storage in the PNS. The transmitter affected by this drug causes an increased heart rate. What response will the nurse expect to see when this drug is administered? a. Bradycardia b. Positive inotropic effects c. Prolonged receptor activation d. Tachycardia ANS: A Drugs that interfere with transmitter storage reduce receptor activation, because disruption of storage decreases the amount of transmitter available for release. Because this transmitter increases the heart rate, the result will be a decrease in the heart rate. Inotropic effects control the force of contraction, not the rate of contraction. Decreased transmitter storage would result in decreased receptor activation. Tachycardia would occur if transmitter availability were increased. PTS: 1 DIF: Cognitive Level: Application REF: pp. 98-99 TOP: Nursing Process: Evaluation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 6. A patient receiving botulinum toxin injections to control muscle spasticity asks how the drug works. The nurse knows that this drug affects the transmitter acetylcholine by: a. inhibiting its release. b. interfering with its storage. c. preventing its reuptake. d. promoting its synthesis. ANS: A Acetylcholine is a neurotransmitter that activates receptors that increase skeletal muscle contraction. Botulinum toxin inhibits the release of this transmitter. It does not interfere with storage, reuptake, or synthesis of acetylcholine. PTS: 1 DIF: Cognitive Level: Application REF: pp. 96-97 TOP: Nursing Process: Implementation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 7. A patient has allergies and takes an antihistamine. The patient wants to know how the drug works. The nurse understands that antihistamines work because they are what? a. Activators b. Agonists c. Antagonists d. Antidotes ANS: C Antihistamines bind to receptors to prevent activation by histamine; this makes antihistamines antagonist drugs. Antihistamines do not activate receptors. Agonist drugs activate receptors; they are not antidotes. PTS: 1 DIF: Cognitive Level: Application REF: pp. 98-99 TOP: Nursing Process: Implementation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 8. A nursing student asks about drugs that interfere with the termination of transmitter action. Which statement by the nurse is correct? a. “Drugs act on this process by altering the diffusion of the transmitter away from the synaptic gap.” b. “Drugs can interfere with termination by either increasing or decreasing reuptake of the transmitter.” c. “Drugs in this category lead to decreased activation by the transmitter in the synapse.” d. “These drugs reduce either reuptake or degradation of the transmitter, causing an increase in receptor activation.” ANS: D Drugs that interfere with termination of transmitter action do so by blocking transmitter reuptake or inhibiting transmitter degradation, resulting in increased receptor activation, because more of the transmitter remains available. Diffusion of the transmitter occurs naturally, but it is a slow process with little clinical significance. Drugs that alter this process cause a decrease in reuptake, not an increase. The effect of drugs that interfere with termination of transmitter action is increased activation. PTS: 1 DIF: Cognitive Level: Application REF: pp. 98-99 TOP: Nursing Process: Implementation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies