Biphasic Half-life?
Kavain is an interesting kavalactone in that it has what is termed as a “biphasic” half-life. Half-life refers to the time it requires for the body to metabolize half of a given substance. Chemicals can have different types of half-lives and two of these types are known as one compartment or single-phase half-life, and biphasic or two compartment half-lives.
In figure 1.2, representing single phase or “one component” model, you can see how the concentration of the compound decreases slowly over a set time. In this scenario the chemical goes from peak concentration in the body, providing maximum effects, through a steady metabolization rate until the concentrations reach zero.
In figure 1.4 we are shown the decrease in concentration in what is known as a two-compartment or “biphasic” model. Here we see the concentration reduce quite sharply at the beginning and then slowly taper down after the first drop off [1].
A study has shown that kavain uses this biphasic model in metabolization. The bulk of kavain burns off quickly (within 50 minutes) with the remainder taking a further 9 hours for the second phase of metabolization [2]. This may explain why kava imparts a short-lived euphoric stimulation which fades rapidly into a more sedative type experience.
[1] Dhillon, S., & Gill, K. (2012). Introduction to pharmacokinetics. Basic Pharmacokinetics, 6-7. doi:10.1201/b11681-4 (http://www.pharmpress.com/files/docs/clinical_pharmacokinetics_samplechapter.pdf)
[2] European Medicines Agency. Assessment report on Piper methysticum G. Forst., Rhizome. Committee on Herbal Medicinal Products. 2018. EMA/HMPC/450589/2016. Page 54. https://www.ema.europa.eu/en/docume...port-piper-methysticum-g-forst-rhizoma_en.pdf, PDF File.
Kavain is an interesting kavalactone in that it has what is termed as a “biphasic” half-life. Half-life refers to the time it requires for the body to metabolize half of a given substance. Chemicals can have different types of half-lives and two of these types are known as one compartment or single-phase half-life, and biphasic or two compartment half-lives.
In figure 1.2, representing single phase or “one component” model, you can see how the concentration of the compound decreases slowly over a set time. In this scenario the chemical goes from peak concentration in the body, providing maximum effects, through a steady metabolization rate until the concentrations reach zero.
In figure 1.4 we are shown the decrease in concentration in what is known as a two-compartment or “biphasic” model. Here we see the concentration reduce quite sharply at the beginning and then slowly taper down after the first drop off [1].
A study has shown that kavain uses this biphasic model in metabolization. The bulk of kavain burns off quickly (within 50 minutes) with the remainder taking a further 9 hours for the second phase of metabolization [2]. This may explain why kava imparts a short-lived euphoric stimulation which fades rapidly into a more sedative type experience.
[1] Dhillon, S., & Gill, K. (2012). Introduction to pharmacokinetics. Basic Pharmacokinetics, 6-7. doi:10.1201/b11681-4 (http://www.pharmpress.com/files/docs/clinical_pharmacokinetics_samplechapter.pdf)
[2] European Medicines Agency. Assessment report on Piper methysticum G. Forst., Rhizome. Committee on Herbal Medicinal Products. 2018. EMA/HMPC/450589/2016. Page 54. https://www.ema.europa.eu/en/docume...port-piper-methysticum-g-forst-rhizoma_en.pdf, PDF File.