Quantitation of escitalopram and its metabolites by liquid chromatography-tandem mass spectrometry in psychiatric patients: New metabolic ratio establishment

Assessment of Pharmacokinetic Effects of Herbal Medicines on Escitalopram

Purpose

Herbal medicines are occasionally used in combination with conventional antidepressants to mitigate various depression-associated symptoms. However, there is limited information on herb-antidepressant interactions. In this study, we investigated the pharmacokinetic (PK) effects of four herbal medicines (Gami-soyosan, Banhasasim-tang, Ojeok-san, and Bojungikgi-tang) on escitalopram, a commonly used antidepressant.

Patients and Methods

In this open-label, fixed-sequence, three-period, crossover study, 18 participants were enrolled and divided into two groups. Each group received a 10 mg oral dose of escitalopram in period 1. Participants took escitalopram once daily and their assigned herbal medicines thrice a day for 7 d in periods 2 (group 1: Gami-soyosan, group 2: Ojeok-san) and 3 (group 1: Banhasasim-tang; group 2: Bojungikgi-tang). The primary endpoints were Cmax,ss and AUCtau,ss of escitalopram. Cmax,ss and AUCtau,ss in period 1 were obtained using nonparametric superposition from single-dose data. The PK endpoints were classified according to the CYP2C19 phenotype.

Results

Of 18 participants, 16 completed the study. Systemic exposure to escitalopram resulted in a minor increase in the presence of each herbal medicine. The geometric mean ratios (GMRs, combination with herbal medicines/escitalopram monotherapy) and their 90% confidence intervals (CIs) for Cmax,ss and AUCtau,ss were as follows: Gamisoyosan- 1.1454 (0.9201, 1.4258) and 1.0749 (0.8084, 1.4291), Banhasasim-tang-1.0470 (0.7779, 1.4092) and 1.0465 (0.7035, 1.5568), Ojeok-san-1.1204 (0.8744, 1.4357) and 1.1267 (0.8466, 1.4996), and Bojungikgi-tang-1.1264 (0.8594, 1.4762) and 1.1400 (0.8515, 1.5261), respectively. Furthermore, no significant differences in the GMRs of Cmax,ss and AUCtau,ss were observed across different CYP2C19 phenotypes in any of the groups.

Conclusion

The co-administration of escitalopram with Gami-soyosan, Banhasasim-tang, Ojeok-san, or Bojungikgi-tang did not exert significant PK effects on escitalopram. These findings provide valuable insights into the safe use of herbal medicines along with escitalopram.

Development and validation of UHPLC-MS/MS method for simultaneous quantification of escitalopram and its major metabolites in human plasma and its application in depressed patients

Escitalopram, one of the Selective Serotonin Reuptake Inhibitors (SSRIs), has been widely used in the patients with major depression. In this study, a simple, sensitive and rapid method was established and validated for simultaneous quantification of Escitalopram (S-CT), desmethyl escitalopram (S-DCT), didemethyl escitalopram (S-DDCT) and escitalopram N-Oxide (S-NOCT) in human plasma by ultra-high performance liquid chromatography-tandem with mass spectrometry (UHPLC-MS/MS). Analytes were extracted from plasma by utilizing protein precipitation and then separated on a Hypersil GOLD C18 column (50 mm × 2.1 mm, 1.9 µm). The mobile phase was water: acetonitrile (70:30, v/v) with 0.25% formic acid at a flow-rate of 0.3 mL/min, within a 5 min run time. The mass analysis used positive electro-spray ionization (ESI) in selection reaction monitoring (SRM). The calibration ranges of the analytes were: S-CT: 2.0-200.0 ng/mL, S-DCT: 1.0-100.0 ng/mL, S-DDCT: 0.5-50.0 ng/mL, S-NOCT: 0.2-20.0 ng/mL. The method has been fully validated for selectivity, linearity, accuracy, precision, matrix effect, recovery, stability and carry over and all the results met the admissible limits according to the the US Food and Drug Administration guidelines. Mean plasma concentration (ng/mL) of S-CT, S-DCT, S-DDCT and S-NOCT in 93 depressed patients were 51.10 ± 45.73, 10.32 ± 15.25, 1.53 ± 1.79 and 0.87 ± 0.94, respectively. it is the first time that a UHPLC-MS/MS method for simultaneous quantification of S-CT and its 3 metabolites in human plasma was established and validated.