C_min

$C min$ is a term used in pharmacokinetics for the minimum blood plasma concentration reached by a drug during a dosing interval, which is the time interval between administration of two doses. This definition is slightly different from $C trough$ , the concentration immediately prior to administration of the next dose.^[1] $C min$ is the opposite of $C max$ , the maximum concentration that the drug reaches. $C min$ must be above certain thresholds, such as the minimum inhibitory concentration (MIC), to achieve a therapeutic effect.^[2]

In most cases $C min$ is directly measurable. At steady state the minimum plasma concentration can also be calculated using the following equation:^[3] $C_{min}={\frac {SFDk_{a}}{V_{d}(k_{a}-k)}}\times \left({\frac {e^{-k\tau }}{1-e^{-k\tau }}}-{\frac {e^{-k_{a}\tau }}{1-e^{-k_{a}\tau }}}\right)$

S

= Salt factor

F

= Bioavailability

D

= Dose

k e

= Elimination rate constant

k a

= Absorption rate constant

V d

= Volume of distribution

τ

= Dosing interval

$C min$ is also an important parameter in bioavailability and bioequivalence studies, it is part of the pharmacokinetic information recommended for submission of investigational new drug applications.^[4]

References

^ Weimann, H. J.; Cawello, W.; Brett, M.; Zimmermann, H.; Pabst, G.; Sierakowski, B.; Giesche, R.; Baumann, A. (1999). "Drug concentrations and directly derived parameters". Parameters for Compartment Free Pharmacokinetics: Standardisation of Study Design, Data Analysis and Reporting. Aachen, Germany: Shaker-Verlag. pp. 25–40. ISBN 9783826547676. OCLC 44511664. (pages 31–34 in 2003 edition)
^ Dalton, Bruce R. (March 2023). "What Is the Best Vancomycin Therapeutic Drug Monitoring Parameter to Assess Efficacy? A Critical Review of Experimental Data and Assessment of the Need for Individual Patient Minimum Inhibitory Concentration Value". Microorganisms. 11 (3): 567. doi:10.3390/microorganisms11030567. ISSN 2076-2607. PMC 10051726. PMID 36985141.
^ http://www.pharmpress.com/files/docs/clinical_pharmacokinetics_samplechapter.pdf Archived 29 March 2018 at the Wayback Machine ^{[bare URL PDF]}
^ https://www.fda.gov/downloads/Drugs/.../Guidances/ucm070124.pdf ^{[bare URL PDF]}

This pharmacology-related article is a stub. You can help Wikipedia by expanding it.

[1] Weimann, H. J.; Cawello, W.; Brett, M.; Zimmermann, H.; Pabst, G.; Sierakowski, B.; Giesche, R.; Baumann, A. (1999). "Drug concentrations and directly derived parameters". Parameters for Compartment Free Pharmacokinetics: Standardisation of Study Design, Data Analysis and Reporting. Aachen, Germany: Shaker-Verlag. pp. 25–40. ISBN 9783826547676. OCLC 44511664. (pages 31–34 in 2003 edition)

[2] Dalton, Bruce R. (March 2023). "What Is the Best Vancomycin Therapeutic Drug Monitoring Parameter to Assess Efficacy? A Critical Review of Experimental Data and Assessment of the Need for Individual Patient Minimum Inhibitory Concentration Value". Microorganisms. 11 (3): 567. doi:10.3390/microorganisms11030567. ISSN 2076-2607. PMC 10051726. PMID 36985141.

[3] ttp://www.pharmpress.com/files/docs/clinical_pharmacokinetics_samplechapter.pdf Archived 29 March 2018 at the Wayback Machine ^{[bare URL PDF]}

[4] ttps://www.fda.gov/downloads/Drugs/.../Guidances/ucm070124.pdf ^{[bare URL PDF]}

[1]