AEMCA Practice Exam

What distinguishes selective drugs from non-selective drugs?

1. Selective drugs have more side effects

2. Selective drugs affect only certain receptors

3. Non-selective drugs are safer

4. Non-selective drugs are used for emergencies

The correct answer is: Selective drugs affect only certain receptors

Selective drugs are characterized by their ability to bind and exert effects on specific receptors, which allows them to target particular biological pathways or systems within the body. This specificity can lead to a more focused therapeutic effect, minimizing the impact on other receptors that may lead to side effects. For instance, a drug that selectively binds to a specific type of receptor, such as a beta-1 adrenergic receptor, will primarily influence heart rate and contractility while largely avoiding interactions with other receptor types, which could potentially lead to unwanted side effects. Non-selective drugs, on the other hand, can interact with multiple receptor types within the body. This broader interaction profile may lead to beneficial effects but also increases the risk of side effects due to unintended actions on non-target receptors. While non-selective drugs may be useful in certain situations, such as emergencies where a rapid and broad effect is required, they are not inherently safer than selective drugs. The distinction primarily lies in the specificity of receptor interaction, which plays a crucial role in the efficacy and safety profiles of pharmacological agents.