Introduction

Drugs are chemical substances with low molecular masses, typically ranging from 100 to 500 atomic mass units (u). These substances interact with specific macromolecular targets within the body to produce a biological response. When this response is therapeutic and beneficial, the substances are termed medicines and are employed in the diagnosis, prevention, and treatment of diseases. However, it is crucial to note that most medicinal drugs can become toxic if taken in doses higher than those recommended. The use of chemicals for therapeutic purposes is referred to as chemotherapy.

Classification of Drugs

Drugs can be classified based on various criteria. Here are the main classifications:

1.On the Basis of Pharmacological Effect

This classification groups drugs according to their effects on the body. It is particularly useful for healthcare professionals, as it helps them choose from a range of drugs for treating specific conditions. Examples include:

i.Analgesics: These drugs provide pain relief.

ii.Antiseptics: These drugs kill or inhibit the growth of microorganisms.