How does increased lipid solubility affect potency and duration?

How does increased lipid solubility affect potency and duration?

• A. Decreases
• B. Increases
• C. No effect
• D. Only duration increases

Answer: (B)

Higher lipid solubility improves the drug’s ability to cross lipid membranes and reach the site of action, so more drug effectively reaches receptors and produces an effect at a given dose. That makes the drug act more potently because available concentration at the target is greater. At the same time, lipophilic drugs tend to distribute widely into fatty tissues and other compartments, creating a reservoir that releases the drug slowly. This slower elimination and prolonged presence in the body extend how long the drug remains active, increasing its duration of action. In short, more lipid solubility generally boosts both potency and duration.

Higher lipid solubility improves the drug’s ability to cross lipid membranes and reach the site of action, so more drug effectively reaches receptors and produces an effect at a given dose. That makes the drug act more potently because available concentration at the target is greater. At the same time, lipophilic drugs tend to distribute widely into fatty tissues and other compartments, creating a reservoir that releases the drug slowly. This slower elimination and prolonged presence in the body extend how long the drug remains active, increasing its duration of action. In short, more lipid solubility generally boosts both potency and duration.