Peak time (Tmax) is defined as which of the following?

Peak time (Tmax) is defined as which of the following?

• A. Time to reach maximum concentration
• B. Maximum concentration achieved
• C. Time to reach half of Cmax
• D. Time to start of absorption

Answer: (A)

Peak time, Tmax, is the time after dosing at which the drug’s plasma concentration reaches its highest point (the maximum concentration, Cmax). It tells you how fast the drug is absorbed relative to how it is cleared, not how much of the drug is in the blood. The actual amount at that peak is Cmax, not Tmax. The start of absorption would occur earlier in the curve, and the time to reach half of the maximum is not what Tmax measures. In a concentration–time profile, Tmax is simply the x-value where the curve reaches its peak.

Peak time, Tmax, is the time after dosing at which the drug’s plasma concentration reaches its highest point (the maximum concentration, Cmax). It tells you how fast the drug is absorbed relative to how it is cleared, not how much of the drug is in the blood. The actual amount at that peak is Cmax, not Tmax. The start of absorption would occur earlier in the curve, and the time to reach half of the maximum is not what Tmax measures. In a concentration–time profile, Tmax is simply the x-value where the curve reaches its peak.