High Variability in the Exposure of Baclofen in Alcohol Dependent Patients

[Ne/Neva Eva]

I think this is research-type-evidence that dosage is really very individual. I won't pretend to understand much of it, though.

In the discussion there is this:

This study showed that the exposure (area under the curve) of baclofen increased proportionally from 30 to 240 mg per day. These results demonstrate that the pharmacokinetics of baclofen is linear over the entire dose range examined. The linearity of baclofen exposure facilitates dosage adjustments because there is no saturation of baclofen clearance at the doses used in the treatment of alcoholism. However, prescribers have to keep in mind that a wide interpatient variability exists. Indeed, we found an interindividual variability of 56.0% on the estimated clearance and 68.3% on the estimated volume of distribution of baclofen. Covariate modeling did not identify covariates that could explain this variability in CL and V. This means that the interindividual variability is not related to demographic and biological factors investigated in this study as well as to the tobacco consumption. This pharmacokinetic variation is likely to impact on treatment outcome. Indeed, a similar dosage can lead to an exposure varying from simple to double (Fig. 3) and thus be responsible for difference of response. Meanwhile the relationship between clinical efficacy and pharmacokinetic parameters of baclofen required further exploration, searching a possible association between baclofen exposure and clinical outcome.

Marsot, A., Imbert, B., Alvarez, J.-C., Grassin-Delyle, S., Jaquet, I., Lan?on, C. and Simon, N. (2014), High Variability in the Exposure of Baclofen in Alcohol-Dependent Patients. Alcoholism: Clinical and Experimental Research, 38: 316–321. doi: 10.1111/acer.12235