Desensitization (pharmacology)

Desensitization (pharmacology)

Desensitization, also known as drug tolerance, is a phenomenon in pharmacology where a subject's reaction to a specific drug decreases, resulting in the need for higher doses to achieve the same effect. This process can occur with both therapeutic drugs and substances of abuse.

Mechanism of Action

Desensitization occurs at the cellular level, involving changes in the number or sensitivity of receptors on the cell surface. This can be due to the internalization of receptors, a process known as downregulation, or changes in the receptor's ability to bind to the drug, known as receptor desensitization.

Types of Desensitization

There are two main types of desensitization: acute and chronic. Acute desensitization occurs rapidly, within minutes to hours of drug exposure, and is often reversible. Chronic desensitization, on the other hand, develops over a longer period of time, often weeks to months, and can be irreversible.

Clinical Implications

Desensitization has significant implications in the field of medicine. It can affect the efficacy of drugs, requiring dose adjustments and careful monitoring. It is also a key factor in the development of drug addiction, as individuals may increase their drug use to achieve the desired effect.

See Also

• Tachyphylaxis
• Pharmacokinetics
• Pharmacodynamics
• Drug metabolism