How is tolerance defined in pharmacology?

Tolerance in pharmacology refers to the phenomenon where there is a decrease in the effectiveness of a drug that occurs after its prolonged use. This means that over a longer period, the body adapts to the presence of the drug, leading to a reduced response to its therapeutic effects. As the body becomes accustomed to the medication, higher doses may be required to achieve the same effect that was originally attained at lower doses.

In this context, the long-term aspect is key, as it differentiates tolerance from other processes that may occur within shorter timeframes, such as rapid desensitization of receptors, which may happen more quickly and do not necessarily indicate a lasting change in drug responsiveness. The potential for increased receptor numbers or alterations in receptor sensitivity often also plays a role in drug tolerance, but the core definition captures the gradual decrease in response over extended use. This understanding is crucial for midwifery students when managing medications for their patients, ensuring they can identify and adjust treatment plans effectively.