Classification of Drugs

Summary

In this lecture, the instructor discusses various ways drugs can be classified. Drugs can be categorized by their origins, mode of action, and chemical structure. The three primary modes of action are etiological, substitutive, and symptomatic, with explanations on how these treat diseases differently. The ATC (Anatomical Therapeutic Chemical) system is also explored, detailing how it classifies drugs based on the organ system they affect, from broad categories to specific substances. The example of 'Meing' is used to illustrate how the ATC system works in practice, showcasing its multiple levels of classification.

Takeaways

• 😀 Drugs can be classified based on their origin, including natural products, fermentation, or synthetic methods.
• 😀 Drugs are classified by their mode of action, which can be eological, substitutive, or symptomatic treatment.
• 😀 Eological drugs focus on selective toxicity, targeting invaders without harming the host, known as the 'Magic Bullet.'
• 😀 Substitutive drugs are used to counteract deficiencies, such as insulin for diabetes or estrogen for menopausal women.
• 😀 Symptomatic treatment drugs manage symptoms like pain or fever but do not address the underlying cause.
• 😀 Drugs like aspirin and morphine share similar effects (pain relief) but act on different mechanisms, illustrating a limitation of classification by mode of action.
• 😀 The ATC (Anatomical Therapeutic Chemical) classification system divides drugs into categories based on where they act in the body system.
• 😀 The ATC system is published by the WHO and organizes drugs into five levels, starting with main groups and narrowing down to specific substances.
• 😀 The first level of the ATC system categorizes drugs into 14 main groups based on the organ or system they target.
• 😀 The ATC classification allows for a detailed breakdown of drugs, from the general organ system to specific chemical subgroups and pharmaceutical substances, using a code-based structure.
• 😀 The example of metformin is used to show how drugs are classified in the ATC system, starting from a broad category like 'elementary tract and metabolism' to specific pharmaceutical substances.

Q & A

What are the different ways drugs can be classified?

Drugs can be classified based on their origins, mode of action, chemical structure, and the nature of the illness they treat.

How are drugs classified according to their origin?

Drugs can be classified by their origin into three categories: natural products (derived from plants, animals, or minerals), fermentation (produced through microbial processes), and semi-synthetic or synthetic drugs (chemically modified or entirely lab-created).

What are the three types of drugs based on their mode of action?

The three types of drugs based on their mode of action are: etiological drugs (target the cause of the disease), substitutive drugs (replace or supplement substances in the body), and symptomatic drugs (alleviate symptoms without addressing the root cause).

What is the principle behind etiological drugs?

The principle behind etiological drugs is selective toxicity, or the 'Magic Bullet' concept, which aims to destroy the disease-causing agents without harming the host (the patient).

Can you explain the difference between symptomatic treatment and etiological treatment?

Symptomatic treatment alleviates symptoms like pain or fever without addressing the underlying cause of the disease, while etiological treatment targets the root cause of the illness, such as eliminating pathogens or correcting a physiological imbalance.

What are substitutive drugs and give an example?

Substitutive drugs replace or supplement substances that the body is deficient in. An example is insulin, which is used to treat diabetes by replacing the insulin the body is unable to produce.

What is the limitation of classifying drugs by their mode of action?

The limitation is that drugs with similar effects, like aspirin and morphine (both painkillers), may act on different pathways in the body, making this classification system less precise in distinguishing between drugs with similar therapeutic effects.

How are drugs classified by chemical structure and why is this important?

Drugs are classified by their chemical structure to help pharmaceutical research, as it allows scientists to compare similar drugs and study how variations in chemical structure might affect their function and side effects.

What is the ATC classification system and how does it work?

The ATC (Anatomical Therapeutic Chemical) classification system categorizes drugs based on the organ or system they affect. It has five levels, from general categories (like the organ system targeted) to specific pharmaceutical substances.

Can you explain how meformin is classified in the ATC system?

Meformin is classified in the ATC system as follows: Level 1—Endocrine System, Level 2—used in diabetes treatment, Level 3—blood glucose-lowering drugs, Level 4 and 5—more specific subgroups, ultimately identifying the substance as meformin.