Correlation of haloperidol levels between saliva and plasma of acutely ill schizophrenic patients

ObjectiveClinical usefulness of monitoring haloperidol in salivary samples based on plasma:saliva correlation.Design and MethodsPlasma and saliva samples of schizophrenic patients [N = 105] were analyzed by highly sensitive reverse phase liquid chromatographic method to measure haloperidol at 240 nm using UV-PDA detector. Mobile phase consist of acetonitrile and water [50:50], pH 2.5 (0.1% acetic acid and 0.05 M KHPO4) at flow rate 1.4 mL/min. Method was linear over 3–200 ng/mL.ResultsObserved therapeutic range was 5–19 ng/mL [11.66 ± 3.97] and 17–54 ng/mL [27.52 ± 11.51] for plasma and saliva respectively. Mean S:P was found to be 2.36.ConclusionCurrent study showed significantly high correlation [r = 0.93, p < 0.0001] between haloperidol levels in saliva and plasma with linear relationship. It is therefore concluded that monitoring of salivary concentration can be a clinically beneficial substitute. Patients showing clinical improvement [N = 90] were within salivary concentration range of 17–54 ng/mL, which can be an appropriate steady state monitoring range for haloperidol in saliva.