The time it takes for a drug to reach the maximum concentration (Cmax) after administration of a drug that needs to be absorbed (e.g. an oral drug).

Tmax is governed by the rate of drug absorption and the rate of drug elimination. At Tmax, these are equal.

Tmax is a key pharmacokinetic parameter. It is an important factor to consider when selecting dosing regimens and dosing intervals. From a clinical perspective, it indicates when antibacterial activity is highest and bacterial growth inhibition or death most likely.