• This study measured the levels of imipramine hydrochloride and desipramine hydrochloride (desmethylimipramine) in the plasma and cerebrospinal fluid (CSF) in 11 depressed patients. The oral doses correlated significantly with the plasma levels irrespective of different diagnostic categories. The CSF levels varied significantly. In the endogenous depressive group the CSF levels were significantly higher in responders as compared to nonresponders. The CSF levels of the nonresponders in the endogenous depressive group, and of both responders and nonresponders in the schizo-affective groups, were similar.
Sathananthan GL, Gershon S, Almeida M, Spector N, Spector S. Correlation Between Plasma and Cerebrospinal Levels of Imipramine. Arch Gen Psychiatry. 1976;33(9):1109–1110. doi:10.1001/archpsyc.1976.01770090099009