Comparison of two approaches to amitriptyline dose individualisation

Individualisation of an amitriptyline dose regimen offers substantial advan tages over non-individualised treatment. In our study, we have compared bot h clinical effects, adverse effects and plasma steady-state concentrations of amitriptyline in 15 patients with major depressive disorder divided in t hree groups: (i) patients in group A were taking non-individualised doses o f amitriptyline; (ii) patients in group B were taking doses of amitriptylin e individualised by modified Bayesian method; and (3) patients in group C w ere taking doses of amitriptyline individualised by the multiple point meth od. The treatment course was 8 weeks long, in the setting of a psychiatric clinic. The patients in group A were taking significantly higher doses thro ughout the treatment course; the initial doses for the patients in group B were higher than doses for the patients in group C, but after corrections b ased on measured steady-state plasma concentrations they became similar. Wh ile Hamilton score descended uniformly in all three groups, both adverse ef fects and steady-state plasma concentrations of amitriptyline were higher i n non-individualised group during the whole treatment course. The results o f our study suggest that the multiple points method is the most precise, bu t tedious and not practical. The modified Bayesian method with correction b ased on first measured plasma steady-stale concentration of amitriptyline o ffers similar therapeutic outcome and adverse effects score combined with l ow cost and being easy-to-use.