A drug with a short half-life will typically require more frequent dosing.

A drug with a short half-life will typically require more frequent dosing.

• A. Fewer doses per day
• B. More frequent dosing
• C. Higher lethal dose
• D. Higher potency

Answer: (B)

Half-life is the time it takes for the drug’s plasma concentration to drop by half. A short half-life means the drug is cleared from the body quickly, so its levels fall rapidly between doses. To keep the drug within the therapeutic range, dosing must be more frequent, ensuring the concentration stays effective rather than dipping too low. If you dose less often, the drug may not stay at active levels long enough to provide the desired effect. The other factors—higher lethal dose or higher potency—affect safety margins or the amount needed per dose, not how often the drug must be given, and fewer doses per day would be more typical of a drug with a longer half-life.

Half-life is the time it takes for the drug’s plasma concentration to drop by half. A short half-life means the drug is cleared from the body quickly, so its levels fall rapidly between doses. To keep the drug within the therapeutic range, dosing must be more frequent, ensuring the concentration stays effective rather than dipping too low. If you dose less often, the drug may not stay at active levels long enough to provide the desired effect. The other factors—higher lethal dose or higher potency—affect safety margins or the amount needed per dose, not how often the drug must be given, and fewer doses per day would be more typical of a drug with a longer half-life.