ATI RN
Pharmacology of CNS Drugs Questions
Question 1 of 5
Following is a G-protein coupled receptor
Correct Answer: D
Rationale: In the context of pharmacology of CNS drugs, understanding G-protein coupled receptors is crucial as they play a significant role in mediating various physiological responses within the central nervous system. The correct answer, option D) Metabotropic, is a G-protein coupled receptor. The rationale for why option D is correct lies in the fact that metabotropic receptors are a class of G-protein coupled receptors that typically have slower and longer-lasting effects compared to ionotropic receptors like AMPA, Kainate, and NMDA receptors. Metabotropic receptors signal through secondary messenger systems involving G-proteins, ultimately leading to modulation of cellular processes. Regarding why the other options are incorrect: - Option A) AMPA and option B) Kainate are ionotropic glutamate receptors, which are ligand-gated ion channels that mediate fast excitatory neurotransmission. - Option C) NMDA is also an ionotropic glutamate receptor that plays a crucial role in synaptic plasticity and memory formation, distinct from G-protein coupled receptors like Metabotropic receptors. Educationally, knowing the distinction between ionotropic and metabotropic receptors is fundamental in understanding the diverse mechanisms of action of CNS drugs. This knowledge is essential for pharmacology students to grasp how different receptors function and how drugs targeting these receptors can have varying effects on neuronal signaling and overall CNS function.
Question 2 of 5
Within days of starting haloperidol treatment for a psychiatric disorder, a young male patient developed severe generalized muscle rigidity and a high fever. In the emergency room he was incoherent, with increased heart rate, hypotension, and diaphoresis. Laboratory studies indicated acidosis, leukocytosis, and increased creatine kinase. The most likely reason for these symptoms is that the patient was suffering from
Correct Answer: C
Rationale: In this case, the correct answer is C) Neuroleptic malignant syndrome (NMS). NMS is a rare but potentially life-threatening side effect of antipsychotic medications like haloperidol. The patient's presentation of severe muscle rigidity, high fever, altered mental status, autonomic instability (increased heart rate, hypotension, diaphoresis), acidosis, leukocytosis, and increased creatine kinase levels are all classic indicators of NMS. Option A) Agranulocytosis is a condition characterized by a low number of white blood cells and is not associated with the symptoms described in the case. Option B) A severe bacterial infection would typically present with more specific signs of infection like localized pain, redness, or purulent discharge, which are absent in this patient. Option D) Spastic retrocollis is a term used to describe a specific type of neck movement and is not related to the constellation of symptoms seen in NMS. From an educational perspective, understanding the side effects and potential complications of CNS drugs is crucial for healthcare providers managing patients on these medications. Recognizing the signs and symptoms of NMS is essential for prompt diagnosis and management to prevent serious complications. This case highlights the importance of monitoring patients closely when initiating antipsychotic therapy and the need for healthcare providers to be vigilant for potentially life-threatening adverse reactions.
Question 3 of 5
Which one of the following statements about propoxyphene is accurate?
Correct Answer: B
Rationale: In pharmacology of CNS drugs, it is crucial for students to understand the accurate information about various medications to ensure safe and effective clinical practice. In the case of propoxyphene, the correct statement is option B) Seizures have occurred in overdose. This is because propoxyphene, which is a mild opioid analgesic, has been associated with a higher risk of seizures, especially in cases of overdose. This information is essential for healthcare professionals to be aware of when prescribing or managing patients on this medication. Now, let's analyze why the other options are incorrect: A) Analgesia equivalent to oxycodone: This statement is incorrect as propoxyphene is considered to be a weaker opioid compared to oxycodone in terms of analgesic potency. It is not equivalent to oxycodone in terms of pain relief. C) Causes dose-limiting diarrhea: This statement is inaccurate as propoxyphene is not typically known for causing dose-limiting diarrhea. Diarrhea is not a common side effect associated with propoxyphene use. D) Highly effective cough suppressant: This statement is false as propoxyphene is not primarily used as a cough suppressant. It is mainly utilized for mild to moderate pain relief rather than for its antitussive properties. Educationally, understanding the accurate pharmacological characteristics of propoxyphene is vital for students to make informed decisions in clinical practice. Knowing the potential risks and side effects of propoxyphene, such as the risk of seizures in overdose, can prevent adverse outcomes in patient care. This knowledge also helps in proper drug selection and monitoring to ensure patient safety and optimal therapeutic outcomes.
Question 4 of 5
Which one of the following drugs most resembles the psychoactive constituent(s) of St. Johns wort in terms of proposed mechanism of action?
Correct Answer: B
Rationale: The correct answer is B) Fluoxetine. Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), resembles the psychoactive constituent(s) of St. John's wort in terms of proposed mechanism of action. St. John's wort is thought to modulate neurotransmitters such as serotonin, norepinephrine, and dopamine, similar to how SSRIs like fluoxetine work. A) Alprazolam is a benzodiazepine that acts on the GABA-A receptor, not similar to St. John's wort's mechanism of action. C) Levodopa is used in Parkinson's disease to increase dopamine levels, not directly related to St. John's wort's effects on multiple neurotransmitters. D) Methylphenidate is a stimulant used in ADHD that primarily affects dopamine and norepinephrine levels, differing from St. John's wort's broader neurotransmitter modulation. Understanding the pharmacology of CNS drugs is crucial for healthcare professionals to make informed decisions about drug selection and patient care. Recognizing similarities and differences in mechanisms of action helps in prescribing appropriate medications and managing potential drug interactions and side effects.
Question 5 of 5
A psychiatric patient taking medications develops a tremor, thyroid enlargement, and leukocytosis. The drug he is taking is most likely to be
Correct Answer: D
Rationale: In this case, the correct answer is D) Lithium. Lithium is a commonly used mood stabilizer in psychiatric patients. The symptoms described - tremor, thyroid enlargement, and leukocytosis - are classic side effects associated with lithium therapy. Tremor is a common side effect of lithium, affecting up to 70% of patients. Thyroid enlargement, specifically goiter and hypothyroidism, is also a known adverse effect of lithium, occurring in about 5-10% of patients on long-term therapy. Leukocytosis, an increase in white blood cell count, can be seen in patients taking lithium as well. The other options (A) Clomipramine, (B) Haloperidol, and (C) Imipramine are not typically associated with the specific side effects described in the question stem. Clomipramine and Imipramine are tricyclic antidepressants that do not commonly cause these particular symptoms. Haloperidol is a typical antipsychotic known for causing extrapyramidal symptoms like dystonia and akathisia, not the symptoms described. In an educational context, understanding the side effects of commonly used psychiatric medications is crucial for healthcare professionals to effectively monitor and manage patients on these medications. Recognizing the side effect profile of each drug helps in early identification and appropriate management of adverse effects, ensuring optimal patient care and safety.