The measurement of haloperidol and reduced haloperidol in hair as an index of dosage history.

Abstract

1. We report a method for measuring the concentrations of haloperidol (HL) and its major active metabolite, reduced haloperidol (RHL), in human scalp hair. 2. Hair samples were obtained from 59 patients who had been taking HL at fixed daily doses for more than 4 months and whose compliance was good. A morning pre‐dose plasma sample was also obtained from 48 of these patients. 3. The concentrations of HL and RHL in hair (ng mg‐1 hair) correlated significantly both with the daily dose (micrograms kg‐1 body weight) of HL (r = 0.682, P less than 0.001 for HL and r = 0.813, P less than 0.001 for RHL, n = 59) and with the trough concentration (ng ml‐1) of the corresponding compound in plasma at steady state (r = 0.558, P less than 0.001 for HL and r = 0.563, P less than 0.001 for RHL, n = 48). The correlation coefficients were slightly higher using the sum of the concentrations of both substances in hair (r = 0.829 for the correlation with daily dose and r = 0.609 for that with trough concentration). 4. Hair from other patients, in whom the dosage of HL had been changed within a few months prior to sampling, was sectioned into 1 cm‐long portions successively from the roots and the concentrations of both compounds in each portion were measured. Assuming a growth rate of 1‐1.5 cm/month, a history of individual dosage could be deduced in all patients from the distribution of the drug and metabolite along the single hair length.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of Triazolam Involving Its Hydroxy Metabolites in Hair Shaft and Hair Root by Reversed-Phase Liquid Chromatography with Electrospray Ionization Mass Spectrometry and Application to Human Hair Analysis

“…Therefore, the condition of MS analysis was changed from full MS measurement to SIM. The selected ions used for the determination of TZ, 1-HT, 4-HT, 1,4-diHT, and 1-HTd 4 were the quasi-molecular ions, m/z 343, 359, 359, 375, and 363, respectively. Relatively stable baseline was obtained from the SIM.…”

Pharmacological studies on meprobamate incorporation in human beard hair

“…No relationships could be established between opiate levels in hairs and morphine administration in carcinoma patients [23]. On the other hand, some papers reported significant relationships for digoxine, cocaine, phencyclidine, cannabis, morphine [5], haloperidol [16], nicotine [19], or amitriptyline [15]. …”

Using ofloxacin as a time marker in hair analysis for monitoring the dosage history of haloperidol

“…We have shown that an ingested drug, whether administered continuously or intermittently, is deposited in hair in proportion to the dose and that it is captured there, moving outwards along the shaft as the hair grows [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Therefore, it may be possible to consider a strand of hair as a "tape-recorder," which continuously stores all the data about the drug exposure of individual over the past several months, or possibly years.…”

“…Haloperidol and reduced haloperidol were simultaneously measured according to the method previously reported [9]. The HPLC system consisted of a system controller, integrator, pump, autoinjector, column oven (SCL-6B, C-R4A, LC-6A, SIL-6B, CTO-6A, respectively; Shimadzu, Kyoto, Japan), and a Coulochem detector with a guard cell and a high-sensitivity analytical cell (5100A, 5020 and 5011, respectively; ESA, Bedford, MA, USA).…”