Which of the following statements about aspirin is not true?

First, let us recall the basic facts given in the Class-XII Chemistry (NCERT) chapter “Chemistry in Everyday Life”. A drug is said to be neurologically active if it interferes with the transmission of message between nerve and receptor. Tranquilizers and analgesics both fall in this broad category.

Now, aspirin is nothing but acetylsalicylic acid. Its most important pharmacological actions are

(i) analgesic action $$\; ($$ relieves pain $$),$$

(ii) antipyretic action $$\; ($$ reduces fever $$),$$

$$\text{(iii) anti-inflammatory action},$$

(iv) anti-platelet or antiblood-clotting action $$($$ prevents aggregation of platelets $$).$$

With these facts in mind, let us examine each option one by one.

Option A: “It is effective in relieving pain.” We have just listed the analgesic (pain-relieving) property of aspirin. So this statement is correct.

Option B: “It is a neurologically active drug.” Because analgesics are placed under the class of neurologically active drugs in the textbook, this statement is also correct.

Option C: “It has antiblood clotting action.” Aspirin inhibits the enzyme cyclo-oxygenase in platelets, thereby reducing formation of thromboxane $$A_2$$ and preventing platelet aggregation. Hence it indeed shows antiblood-clotting (anti-platelet) action. This statement is correct.

Option D: “It belongs to narcotic analgesics.” Analgesics are of two broad types:

Narcotic (addictive) analgesics such as morphine, codeine, heroin, etc.

Non-narcotic (non-addictive) analgesics such as aspirin, paracetamol, etc.

Aspirin clearly falls in the second category, i.e., non-narcotic analgesics. Therefore calling it a “narcotic analgesic” is wrong.

Among the four given statements, only Option D is not true.

Hence, the correct answer is Option D.