L-carnitine does not improve valproic acid poisoning management: a cohort study with toxicokinetics and concentration/effect relationships

Annals of Intensive Care

Table 2 Parameters of the population toxicokinetic model of plasma valproic acid and parameters of the model of plasma valproic acid/blood lactate concentration relationships in valproic acid-poisoned patients managed in the intensive care unit

Parameters	Mean	CV%
Population toxicokinetic model (n = 19)
k_a (/h)	0.5	Fixed
V_d/F (L)	39.9	28.1
Cl/F (L/h)	1.2	22.1
ke (/h)	0.03	28.1
t_1/2 (h)	22.9	28.1
η_(V/F) (%)	1.1	30.7
η_(Cl/F) (%)	0.9	32.3
ε_prop	0.4	23.0
Relationships between blood lactate and plasma valproic acid concentrations (n = 8)
E₀ (mmol/L)	1.3	43.9
κ (L/mg)	0.003	59.5

k_a, absorption rate constant; V_d/F, apparent volume of distribution; Cl/F, apparent total body clearance; k_e, elimination rate constant; t_1/2, elimination half-life; η_(V/F), inter-individual variability in the apparent volume of distribution; η_(Cl/F), inter-individual variability in the apparent clearance; ε_prop, proportional error of the model; E₀, baseline blood lactate level; κ, rate constant of the effect; CV%, coefficient of variation