Problem 48 - A Complete Resource Book in Chemistry for JEE Main

Question

Which among these is a hypnotic drug? (a) metaldehyde (b) acetaldehyde (c) paraldehyde (d) none of these

Step-by-Step Solution

Answer

The hypnotic drug among the options is (c) paraldehyde.

Step 1: Understanding the Drug Categories

First, classify each option into its respective category before identifying the hypnotic drug. Hypnotic drugs are substances used to induce sleep or sedation.

Step 2: Classify Metaldehyde

Metaldehyde is primarily used as a pesticide, specifically as a molluscicide to control slugs and snails. It is not used for medical purposes and is not classified as a hypnotic drug.

Step 3: Classify Acetaldehyde

Acetaldehyde is a volatile compound that is naturally present in coffee, bread, and ripe fruit. It is more commonly known as an intermediate in ethanol metabolism and is not used as a hypnotic drug.

Step 4: Classify Paraldehyde

Paraldehyde is a sedative and hypnotic drug that was historically used to treat insomnia and manage seizures. Although not commonly used today, it fits the classification of a hypnotic drug.

Step 5: Conclusion

After examining each option, the hypnotic drug among the given choices is paraldehyde, as it was historically used as a sedative and hypnotic.

Key Concepts

Understanding Drug Classification

Drugs are classified based on their effects, uses, and the body systems they affect. This classification helps medical professionals prescribe the right medication for different conditions and manage patient care effectively. When looking at drugs, they can be broadly categorized into several groups such as:

• Analgesics - used for pain relief.
• Antibiotics - used to treat bacterial infections.
• Sedatives and Hypnotics - used to induce sleep or reduce tension.
• Stimulants - increase alertness and energy.
• Anti-inflammatory - used to reduce inflammation.

Drugs classified as sedatives and hypnotics are specifically used to calm the central nervous system. This helps those with sleep disorders by promoting relaxation and sleep. Moreover, a single drug can fall into multiple categories depending on its different effects at various doses or formulations. Understanding drug classifications is key to identifying which substances serve hypnotic and sedative purposes.

Acetaldehyde: An Intermediate in Ethanol Metabolism

Acetaldehyde is scientifically known as an organic chemical compound and a pivotal intermediate in the metabolism of ethanol (alcohol) in the body. When alcohol is consumed, it is converted into acetaldehyde by an enzyme called alcohol dehydrogenase. This acetaldehyde is further processed by another enzyme, acetaldehyde dehydrogenase, into acetic acid, which is then broken down into water and carbon dioxide. The entire process removes alcohol from the body.

Acetaldehyde naturally occurs in coffee, bread, and some ripe fruits, contributing to their flavor profiles. However, high levels of acetaldehyde, especially in the liver, can be toxic and are linked with the hangover effects experienced after consuming alcohol. It is not used as a drug to induce sleep or sedation, thus does not classify as a hypnotic drug.

Paraldehyde: Once a Hypnotic Drug

Paraldehyde is a fascinating compound in the history of medicine. It was once widely used for its sedative and hypnotic properties, especially in treating insomnia or as an anti-seizure medication. Paraldehyde became a popular choice during the late 19th and early 20th centuries due to its calming effects and was found to be effective in inducing sleep without significant aftereffects.

Its usage has declined with the advent of more modern medications with fewer side effects, but it remains a significant part of medical history. Despite being less commonly used today, its classification as a hypnotic remains due to its historical applications in calming both the mind and body when administered. Understanding such compounds provides insight into the evolution of therapeutic agents throughout medical history and helps recognize their role in modern pharmacology.