Quantitative analysis of trazodone in human plasma by using HPLC-fluorescence detector coupled with strong cation exchange chromatographic column: Application to a pharmacokinetic study in Chinese healthy volunteers

Metabolism of m-CPP, trazodone, nefazodone, and etoperidone: clinical and forensic aspects

Trazodone, nefazodone, and etoperidone are classified as atypical antidepressants belonging to the phenylpiperazine class. These antidepressants are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP), which was initially employed in veterinary medicine but has gained widespread use as a recreational drug globally despite legal restrictions in numerous countries. The active metabolite, mCPP, exerts various neuropsychiatric effects by interacting with serotonin receptors. It primarily exhibits nonselective agonistic properties with some antagonistic effects and influences temperature, behavior, and hormone release via central 5-HT receptors. The surge in mCPP popularity can be attributed to its MDMA-like effects, and its initial misidentification as an MDMA substitute facilitated its unregulated distribution worldwide. This review aims to comprehensively explore the pharmacokinetics and pharmacodynamics of these compounds, with a specific focus on the forensic challenges posed by mCPP as a metabolite of antidepressants. The primary objective is to delineate the consumption patterns of these compounds in laboratory settings, making this review crucial for understanding the intricate nuances of these drugs in forensic contexts.

Electropolymerized, Molecularly Imprinted Polymer on a Screen-Printed Electrode-A Simple, Fast, and Disposable Voltammetric Sensor for Trazodone

In recent years, analytical chemistry has been facing new challenges, particularly in developing low-cost, green, and easy-to-reproduce methods. In this work, a simple, reproducible, and low-cost electrochemical (voltammetric) molecularly imprinted polymer (MIP) sensor was designed specifically for the detection of trazodone (TZD). Trazodone (TZD) is an antidepressant drug consumed worldwide since the 1970s. By combining electropolymerization (surface imprinting) with screen-printed electrodes (SPCEs), the sensor is easy to prepare, is environmentally friendly (uses small amounts of reagents), and can be used for in situ analysis through integration with small, portable devices. The MIP was obtained using cyclic voltammetry (CV), using 4-aminobenzoic acid (4-ABA) as the functional monomer in the presence of TZF molecules in 0.1 M HCl. Non-imprinted control was also constructed in the absence of TZD. Both polymers were characterized using CV, and TZD detection was performed with DPV using the oxidation of TZD. The polymerization conditions were studied and optimized. Comparing the TZD signal for MIP/SPCE and NIP/SPCE, an imprinting factor of 71 was estimated, indicating successful imprinting of the TZD molecules within the polymeric matrix. The analytical response was linear in the range of 5-80 µM, and an LOD of 1.6 µM was estimated. Selectivity was evaluated by testing the sensor for molecules with a similar structure to TZD, and the ability of MIP/SPCE to selectively bind to TZD was proven. The sensor was applied to spiked tap water samples and human serum with good recoveries and allowed for a fast analysis (around 30 min).

Prognostic value of liver and kidney function parameters and their correlation with the ratio of urine-to-plasma paraquat in patients with paraquat poisoning

Acute paraquat poisoning resulting from multiple organ failure usually has a high mortality rate. Liver and kidney, as the key oranges of paraquat detoxification and elimination, their injuries may suppress toxin excretion and enhance the toxicity of paraquat in other organs and worsen the prognosis. Therefore, we intended to explore the prognostic value of liver and kidney function parameters, and further evaluate their correlation with a more stable index urine-to-plasma paraquat (urine paraquat concentrations/plasma paraquat concentrations) instead of considering paraquat concentrations in plasma or urine alone. The study included 33 patients with acute paraquat poisoning admitted to four centres in China from January 2018 to December 2019. Seventeen patients (10 male/7 female) survived, whereas 16 patients (7 male/9 female, 48.48%) died from paraquat poisoning. Alanine aminotransferase (ALT) and the blood urea nitrogen (BUN) represent liver and kidney function parameters, respectively. The ratio of urine-to-plasma paraquat is negatively correlated with ALT (r = -0.94, P = 0 .02) and BUN (r = -0.82, P = 0.03). For receiver operating characteristic curve (ROC) analysis, ALT, BUN and urine-to-plasma paraquat have an AUC over 0.80. The study shows that the functional indexes of liver and kidney, as well as the ratio of urine-to-plasma paraquat, could be considered for evaluating the extent of organ injury and excretion rate of paraquat.

Comparative study of β-cyclodextrin, γ-cyclodextrin and 4-tert-butylcalix[8]arene ionophores as electroactive materials for the construction of new sensors for trazodone based on host-guest recognition

BACKGROUND

Trazodone (TRZ) is a second-generation non-tricyclic antidepressant derived from a triazolopyridine derivative, which is mainly used to treat emotional disorders and conditions related to depressive disorders.

PURPOSE

This study investigated the design, development and characteristics of polyvinyl chloride (PVC) membrane sensors for trazodone HCl (TRZ).

METHODS

The developed sensing membranes were constructed using β-cyclodextrin (β-CD; sensor 1), γ-cyclodextrin (γ-CD; sensor 2) or 4-tert-butylcalix[8]arene (t-BC8; sensor 3) ionophores as sensing materials in addition to ionic sites and dioctyl phthalate in the PVC matrix.

RESULTS

Sensors 1, 2 and 3 displayed fast, stable and near-Nernstian response over a relatively wide trazodone concentration range (7.0×10-6-1×10-3, 5.0×10-5-1×10-3and 8.0×10-6-1.0×10-3 M, respectively), with detection limits of 2.2×10-6, 1.5×10-5 and 2.42×10-6 M, respectively in the pH range of 3.0-6.0. The sensors demonstrated good selectivity for TRZ in the presence of different ionic compounds. The accuracy and precision of the proposed sensors were assessed by the determination of 40.7 μg/ml of TRZ, which showed average recoveries of 99.6%, 99.1% and 98.5% with mean relative standard deviations of 2.4%, 2.5% and 2.6% for sensor 1, 2 and 3 respectively. Molecular modeling was used to calculate the host-guest binding energy. The lowest free binding energy was -6.243, -5.752 and -5.7105 kcal/mol for 1:1 stoichiometry host-guest complexes of trazodone and β-CD, γ-CD and t-BC8, respectively, which was in-line with a Nernstian response.

CONCLUSION

The investigated methods can be applied for the determination of TRZ in pharmaceutical preparations. The results of investigated dosage-form of TRZ show good agreement with those using the US Pharmacopeia method.

Pharmacokinetics, pharmacodynamics and clinical use of trazodone and its active metabolite m-chlorophenylpiperazine in the horse

Trazodone is a serotonin receptor antagonist and reuptake inhibitor used extensively as an anxiolytic in human and small animal veterinary medicine. The aims of this study were to determine the pharmacokinetics of oral trazodone in experimental horses and to evaluate the effect of oral trazodone in clinical horses. Six experimental horses were administered trazodone at 7.5 or 10 mg/kg. Plasma concentrations of trazodone and its metabolite (m-CPP) were determined via UPLC-MS/MS. Noncompartmental pharmacokinetic analysis, sedation and ataxia scores were determined. Trazodone was rapidly absorbed after oral administration with a maximum concentration of 2.5-4.1 μg/ml and half-life of the terminal phase of approximately 7 hr. The metabolite was present at low levels in all horses, representing only 2.5% of the total area under the curve. In experimental horses, concentration-dependent sedation and ataxia were noted, lasting up to 12 hr. For clinical cases, medical records of horses treated with trazodone for various abnormal behaviours were reviewed and data were summarized. Trazodone was successful in modifying behavioural problems to some degree in 17 of 18 clinical cases. Tolerance and subsequent lack of drug effect occurred in two of 18 clinical cases following 14 or 21 days of use. In both populations of horses, adverse effects attributed to trazodone include oversedation, muscle fasciculations and transient arrhythmias.

Ion-exchange vs reversed-phase chromatography for separation and determination of basic psychotropic drugs

Ion exchange chromatography, an alternative to reversed-phase (RP) chromatography, is described in this paper. We aimed to obtain optimal conditions for the separation of basic drugs because silica-based RP stationary phases show silanol effect and make the analysis of basic analytes hardly possible. The retention, separation selectivity, symmetry of peaks and system efficiency were examined in different eluent systems containing different types of buffers at acidic pH and with the addition of organic modifiers: methanol and acetonitrile. The obtained results reveal a large influence of the salt cation used for buffer preparation and the type of organic modifier on the retention behavior of the analytes. These results were also compared with those obtained on an XBridge C18 column. The obtained results demonstrated that SCX stationary phases can be successfully used as alternatives to C18 stationary phases in the separation of basic compounds. The most selective and efficient chromatographic systems were applied for the quantification of some psychotropic drugs in fortified human serum samples.