UPUMS Nsg.Officer-2024
Pharmacology
Medium

Which of the following is not an antiparkinsonian drug?

Appeared in: UPUMS Nsg.Officer-2024

Explanation

  • Risperidone is an atypical antipsychotic drug, not an antiparkinsonian agent.
  • Its primary mechanism involves blocking dopamine D2 receptors in the brain.
  • Parkinson's disease is characterized by a deficiency of dopamine. Blocking dopamine receptors with a drug like Risperidone can worsen existing motor symptoms or induce drug-induced parkinsonism (extrapyramidal symptoms).
  • Therefore, its action is counterproductive to treating Parkinson's disease.

Why Other Options Were Wrong

  • Option B: Procyclidine hydrochloride is a centrally acting anticholinergic drug. It is used to treat the symptoms of Parkinson's disease, particularly tremor and rigidity.
  • Option C: Trihexyphenidyl (THP) is another central anticholinergic agent, similar to procyclidine. It is commonly prescribed to manage the motor symptoms of Parkinson's disease and drug-induced extrapyramidal symptoms.
  • Option D: Carbidopa is a peripheral dopa-decarboxylase inhibitor. It is a cornerstone of Parkinson's therapy, administered in combination with levodopa to prevent levodopa's breakdown before it reaches the brain, thereby increasing dopamine levels in the central nervous system.

Related Visual

Visual explanation — Related Visual
Clinical Relevance
  • Nursing practice connection: Knowing Pharmacology of Antiparkinsonian Drugs helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
  • A critical nursing responsibility is to monitor patients on antipsychotic medications like Risperidone for the development of extrapyramidal symptoms (EPS), which mimic Parkinson's disease (e.g., tremors, rigidity, shuffling gait).
  • Administering a dopamine antagonist like Risperidone to a patient with Parkinson's disease can lead to a significant and dangerous worsening of their motor function.
  • Nurses must be aware of potential drug-disease interactions and question orders that could harm the patient.
How to Approach the Question
  • First, identify the keyword 'not' in the question. This indicates you are looking for the option that is an exception.
  • The question asks to identify which drug is NOT an antiparkinsonian drug.
  • Review each option and classify it based on its drug class and primary therapeutic use.
  • Procyclidine and Trihexyphenidyl are anticholinergics used for Parkinson's.
  • Carbidopa is a decarboxylase inhibitor used with Levodopa for Parkinson's.
  • Risperidone is an antipsychotic. Antipsychotics are known to block dopamine, which is the opposite of the therapeutic goal in Parkinson's disease.
Concept Tested & Keywords
  • Concept Tested: Pharmacology of Antiparkinsonian Drugs
  • Stem keywords: antiparkinsonian drug
  • Lead-in keywords: not
  • Negative lead-in flag: This question uses negative framing ('NOT'), requiring you to identify the option that does not fit the category of antiparkinsonian drugs.

Question ID

QfQSQ0vcemr_i1EVZPSqKy

Reference Book

E6 Pharmacology KD Tripathi Essentials 9e Part 2 p. 95-97

E6 Robert Boland, Marcia L. Verduin - Kaplan and Sadock's Comprehensive Text of Psychiatry-Wolters Kluwer Health (2024) (pp 1-16525 of 16525) p. 10783-10785

E6 Kaplan Sadock's Synopsis of Psychiatry-2022 (pp 1-3768 of 3768) p. 2224-2226

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