What is meant by the dual nature of drug action?

Under normal circumstances, the duality of drug action primarily refers to a drug's therapeutic effects and adverse reactions, which is one of the fundamental properties of drug action. A detailed analysis is as follows:

Drugs exert their effects by binding to specific targets in the body. Since human organs and tissues are closely interconnected in function, these targets may be distributed across multiple sites. When a drug acts on the affected area, it can inhibit pathogenic factors or restore impaired functions, thereby producing therapeutic effects. However, when the same drug acts on normal tissues, it may interfere with normal physiological processes and trigger adverse reactions. Furthermore, due to individual differences in metabolism and organ function, the metabolites and intensity of drug effects can vary among individuals. Some people may experience unexpected adverse reactions. As a result, therapeutic effects and adverse reactions inevitably coexist in drug therapy.

Prior to medication use, it is essential to fully understand the drug’s indications and potential adverse reactions, and dosage should not be adjusted without medical guidance. During treatment, closely monitor any bodily changes and seek medical attention promptly if abnormal symptoms occur. Avoid taking multiple drugs with similar ingredients simultaneously to prevent additive adverse effects and ensure safe medication use.