Question

Given below are two statements:
Statement I: Strychnine is not a convulsant.
Statement II: Doxapram is an analeptic agent.
In light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

Remember that Strychnine is the classic textbook example of a spinal convulsant that blocks glycine receptors. Doxapram is the primary clinical respiratory stimulant used in veterinary neonatology.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Neuropharmacology classifies central nervous system (CNS) stimulants into different functional categories based on their mechanisms of action and clinical uses.
These include convulsants (which cause generalized seizures by blocking inhibitory pathways) and analeptics (respiratory and vasomotor stimulants used to treat respiratory depression).

Step 2: Detailed Explanation:
Let us analyze both statements:
1. Statement I: Strychnine is not a convulsant.
This statement is incorrect.
Strychnine is a classic, highly potent, and dangerous central nervous system convulsant toxin.
It acts as a competitive antagonist at glycine receptors, which are major inhibitory neurotransmitter receptors in the spinal cord and brainstem.
By blocking glycine-mediated postsynaptic inhibition, strychnine causes unchecked, generalized reflex excitability.
This leads to severe, painful, tetanic skeletal muscle convulsions (classically characterized by opisthotonus and "sardonic grin") triggered by minimal sensory stimuli.
Therefore, Statement I is false.
2. Statement II: Doxapram is an analeptic agent.
This statement is correct.
Doxapram is a rapid-acting respiratory stimulant, classified as an analeptic agent.
It works by stimulating peripheral chemoreceptors in the carotid and aortic bodies, and at higher doses, by directly stimulating respiratory and vasomotor centers in the medulla oblongata.
In veterinary medicine, it is clinically used to treat emergency respiratory depression induced by anesthetics, barbiturates, or hypoxia in newborn calves, puppies, and kittens.
Therefore, Statement II is true.

Step 3: Final Answer:
Statement I is false because strychnine is a convulsant, but Statement II is true because doxapram is an analeptic.
Therefore, the correct option is (D).