Drugs used to treat nausea and vomiting are all except

Appeared in: NHM UP Staff Nurse-2021 Shift-1st

Explanation

Calcium channel blockers are a class of cardiovascular drugs used primarily to treat hypertension (high blood pressure), angina (chest pain), and certain cardiac arrhythmias.
Their mechanism involves blocking the entry of calcium into the cells of the heart and blood vessel walls, causing them to relax and widen.
This mechanism of action is unrelated to the neurological pathways and receptors (like dopamine, serotonin, or cannabinoid) that control nausea and vomiting.
Therefore, they are not used as antiemetics.

Option A: Dopamine antagonists are a major class of antiemetic drugs.
Option B: Serotonin (5-HT3) receptor antagonists are highly effective and commonly used antiemetics.
Option C: Cannabinoids are recognized for their antiemetic properties.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology of Antiemetic Drugs as background academic context rather than a clinical decision trigger.
A nurse must understand the different classes of antiemetics to administer the correct medication based on the cause of nausea (e.g., chemotherapy, motion sickness, postoperative).
It is crucial to monitor for class-specific side effects. For instance, dopamine antagonists can cause extrapyramidal symptoms (dystonia, restlessness), which require prompt nursing assessment and intervention.
What if? If a patient experiences nausea due to motion sickness, the most appropriate drug class would be H1 antihistamines (like dimenhydrinate) or anticholinergics (like scopolamine), which are more effective for vestibular-related causes than the options listed.

How to Approach the Question

This is a negatively framed 'except' question, which asks you to identify the outlier.
Step 1: Carefully read the question stem and note the keyword 'except'. This means three of the options are antiemetics, and one is not.
Step 2: Systematically evaluate each option, recalling its primary therapeutic use.
Step 3: Confirm that Dopamine antagonists, Serotonin receptor antagonists, and Cannabinoids are all recognized classes of drugs used to treat nausea and vomiting.
Step 4: Identify that Calcium channel blockers are used for cardiovascular conditions like hypertension and have no role in treating emesis.
Step 5: Select the option that does not belong to the category of antiemetic drugs.

Concept Tested & Keywords

Concept Tested: Pharmacology of Antiemetic Drugs
Stem keywords: drugs, treat, nausea, vomiting
Lead-in keywords: except
Negative lead-in flag: This is a negative question asking you to identify the option that is NOT an antiemetic.

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E6 Pharmacology Katzung 16e pp. 1716-1718, 1715-1717

E6 Pharmacology KD Tripathi Essentials 9e Part 2 p. 344-346

Practise the full NHM UP Staff Nurse-2021 Shift-1st

Attempt every question from this paper in a timed mock, then review the full solution for each one.