Time to reach peak concentration
Plasma concentrations reflect a time curve from the administration of a drug through its peak effect and eventual elimination. The time to peak concentration is of pragmatic importance because it varies between individuals and can be manipulated through the various routes of administration (e.g., oral, IV, and topical) or via the modifications to the mechanism of drug delivery. Thalidomide, for example, has an average Tmax of 4 h; however, the time to reach peak concentration can vary between 1 and 7 h (Figg et al. 1999).
Tmax is often related to the length of a drug’s half-life (t½). Drugs with short half-lives tend to peak and eliminate quickly, often requiring more frequent dosing to maintain a drug within its clinically effective therapeutic range. “New” drugs within a class often reflect alterations in the delivery system rather than changes to a drug itself, such as sustained release preparations that alter the speed with...
References and Readings
- Brunton, L. B., Lazo, J. S., & Parker, K. L. (Eds.). (2005). Goodman & Gilman’s the pharmacological basis of therapeutics (11th ed.). New York: McGraw Hill.Google Scholar
- Stahl, S. M. (2008). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications. New York: Cambridge University Press.Google Scholar