Cyclizine induces cytotoxicity and apoptosis in macrophages through the extrinsic and intrinsic apoptotic pathways.

Cyclizine, an over-the-counter and prescription antihistamine, finds widespread application in the prevention and treatment of motion sickness, encompassing symptoms such as nausea, vomiting, dizziness, along with its effectiveness in managing vertigo. However, the overuse or misuse of cyclizine may lead to hallucinations, confusion, tachycardia, and hypertension. The molecular mechanisms underlying cyclizine-induced cytotoxicity and apoptosis remain unclear. During the 24 h incubation duration, RAW264.7 macrophages were exposed to different concentrations of cyclizine. Cytotoxicity was assessed through the lactate dehydrogenase assay. Flow cytometry employing annexin V-fluorescein isothiocyanate and propidium iodide was utilized to evaluate apoptosis and necrosis. Caspase activity and mitochondrial dysfunction were evaluated through a fluorogenic substrate assay and JC-1 dye, respectively. Flow cytometry employing fluorogenic antibodies was utilized to evaluate the release of cytochrome c and expression of death receptor, including tumor necrosis factor-α receptor and Fas receptor. Western blotting was utilized to evaluate the expression of the Bcl2 and Bad apoptotic regulatory proteins. The findings unveiled from the present study demonstrated that cyclizine exerted a concentration-dependent effect on RAW264.7 macrophages, leading to the induction of cytotoxicity, apoptosis, and necrosis. This compound further activated the intrinsic apoptotic pathway by inducing mitochondrial dysfunction, Bcl2/Bad exchange expression, cytochrome c liberation, and activation of caspases contained caspase 3, 8, and 9. Moreover, the activation of the extrinsic apoptotic pathway was observed as cyclizine induced the upregulation of death receptors and increased caspase activities. Based on our investigations, it can be inferred that cyclizine prompts cytotoxicity and apoptosis in RAW264.7 macrophages in a concentration-dependent manner by triggering both the intrinsic and extrinsic apoptotic pathways.

Cyclizine-induced proinflammatory responses through Akt-NFκB pathway in macrophages.

Cyclizine exhibits sedation and treatment of nausea, vomiting, and motion sickness due to antihistaminic and antimuscarinic effects. Cyclizine has the potential for abuse due to the hallucinogenic and euphoric effect. The response of overdose and illegal abuse of cyclizine includes confusion, tremors, chest pain, ataxia, seizures, and lead to suicide. Macrophage plays the important role in the innate immunity. However, over activation of macrophages results in pro-inflammatory responses in peripheral tissues. In the present study, cyclizine was found to enhanced the generation of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. We further found that secretion of nitrogen oxide (NO) induced by cyclizine via expression of inducible nitric oxide synthases (iNOS). Cyclizine exhibited parallel stimulation of phosphorylation of nuclear factor-κB (NFκB) p65, and its up-stream factor Akt. These results indicated that the expression of pro-inflammatory cytokines, pro-inflammatory mediators, and adhesion molecules would be induced by cyclizine via activation of Akt-NFκB pathway in macrophages.

Repeated poisonings in Denmark - a nationwide study.

OBJECTIVE: Poisonings contribute significantly to morbidity and mortality of patients. Some patients have numerous contacts to a poison information center, indicating repeated poisoning exposures. Information on the involved substances is necessary to explore methods to prevent self-harm and reduce mortality. The objective of this study was to characterize the patient population with repeated poison exposures in Denmark and identify the substances involved. METHODS: This study was a retrospective cohort study of enquiries to the nationwide Danish Poison Information Centre and the Danish National Patient Registry. The databases were used to identify patients with more than five individual poisoning episodes within a 12-month-period between 1 January 2013, and 31 December 2017. RESULTS: One hundred and thirty-seven patients and 995 patients met the inclusion criteria in the Danish Poison Information Centre and the Danish National Patient Registry, respectively. The majority were women (82.5% and 66.3% for the Danish Poison Information Centre and the Danish National Patient Registry cohorts, respectively). The mean age was 24.7 and 29.5 years. Psychiatric comorbidities were frequent with 74.5% and 67.0% suffering from personality disorders and 70.1% and 54.5% from affective disorders in the Danish Poison Information Centre and the Danish National Patient Registry cohorts, respectively. One thousand seven hundred and fifty-two poisoning episodes were identified in the Danish Poison Information Centre database, and the most common types of substance were 'pharmaceuticals' (1,420 episodes). The most common medications ingested were quetiapine, paracetamol and cyclizine. Median number of contacts to the Danish Poison Information Centre was 10. Patients with one or more poisoning episodes involving cyclizine had on average 11.4 poisoning episodes involving cyclizine. In the Danish National Patient Registry cohort 80.9% were alive after 10 years compared to 97.7% in the background population. CONCLUSION AND IMPLICATIONS: Most poisonings were intentional and occurred among younger women. Psychiatric comorbidity was frequent. Most often, pharmaceuticals were the toxic substance, mainly quetiapine, paracetamol and cyclizine. Changing the status of cyclizine from over the counter to prescription only medication, and implementing stricter rules for prescribing quetiapine, could limit future poisoning incidences.

Subcutaneous Dihydrocodeine Tartrate: Compatibility in a Syringe Pump With Other Drugs Frequently Prescribed for the Management of Symptoms Associated With Brain Tumors.

BACKGROUND: Dihydrocodeine can be more effective in the management of headache due to brain tumor than other opioids. It can be used as a subcutaneous infusion, but at present, there is little available data to support its use in combination with other medicines in a syringe pump. AIM: This project aimed to establish physical stability data for the use of dihydrocodeine with other drugs when combined in a syringe pump. Design: Dihydrocodeine was combined in a syringe pump with either cyclizine, midazolam, or hyoscine butylbromide at different doses chosen to represent routine clinical practice. Each drug combination was repeated twice-with 0.9% sodium chloride and with water for injections. Setting: The project was conducted in an independent hospice after seeking appropriate approvals to use the drugs for this purpose. RESULTS: Dihydrocodeine and midazolam appear compatible at when 0.9% sodium chloride is used as the diluent. Dihydrocodeine and cyclizine appeared compatible when either 0.9% saline or water for injections was used as the diluent. Dihydrocodeine and hyoscine butylbromide appeared compatible with either diluent at 24 hours. CONCLUSIONS: Physical stability data has been described that will support the use of dihydrocodeine and other drugs that are commonly used to manage symptoms due to brain tumors at the end of life. This information will benefit patients and ensure that one syringe pump can be used where possible. Future work could expand on this data and explore the physical stability of three drug combinations in each syringe.

Comparative Chemometric Manipulations of UV-Spectrophotometric Data for the Efficient Resolution and Determination of Overlapping Signals of Cyclizine and Its Impurities in Its Pharmaceutical Preparations.

BACKGROUND: Cyclizine (CYZ), a commonly used antiemetic drug, has two pharmacopeial toxic impurities, 1-methylpiperazine (MPZ) and diphenylmethanol (DPM). When CYZ parenteral formulations are administered intravenously, both impurities are poisonous, toxic, and harmful to the human body. OBJECTIVE: Cyclizine was determined along with its hazardous impurities MPZ and DPM by green multivariate calibration using UV-spectroscopic data. METHODS: Three multivariate algorithms were used to resolve and quantify overlapped spectral signals: principal component regression (PCR), partial least squares (PLS), and synergistic intervals partial least squares (siPLS). A concentration set containing 16 distinct combinations of CYZ, MPZ, and DPM was randomly prepared, and the absorbance values of the concentration set were determined using the 376 point-wavelength set with an interval of 0.2 nm between 200 and 275 nm. RESULTS: Good linear correlations were established for CYZ, MPZ, and DPM in the concentration ranges of 5.00-25.0, 0.50-2.50, and 0.50-2.50 µg/mL, respectively. The ideal spectral range and associated combinations were chosen based on the lowest root mean error of prediction (RMSEP) and correlation coefficient values (r). The siPLS approach performed better than the PCR and PLS models. The combination of four subintervals, 1, 3, 4, and 7, demonstrated the greatest effect, with RMSEP values of 0.0272, 0.0053, and 0.0315 for CYZ, MPZ, and DPM, respectively, and correlation coefficients of 0.9991, 0.9999, and 0.9997, in order. Various assessment tools were used to evaluate and measure the greenness profile of the established methods. The proposed methods were validated using internal and external validation sets. CONCLUSIONS: The three methods were effectively used to determine CYZ in its pure form and parenteral formulations, as well as its toxic impurities. The acquired results were compared statistically to those obtained using the reported HPLC method. HIGHLIGHTS: Cyclizine and its toxic impurities can be determined spectrophotometrically by using the three developed chemometric models.

Spectrofluorimetric Approach for Quantification of Cyclizine in the Presence of its Toxic Impurities in Human Plasma; in silico Study and ADMET Calculations.

Cyclizine (CYZ); an antiemetic compound; is widely misused for its euphoric or hallucinatory effects, either by oral or intravenous routes. The concomitant abuse of CYZ among addicted adolescents contributes to neuromuscular disorders that are life-threatening. Consequently, with the company of 1-Methylpiperazine (MPZ) and diphenylmethanol (DPM, Benzhydrol) as pharmacopoeia-reported CYZ impurities, a novel spectrofluorimetric assay for the detection of CYZ, has been established either in human plasma samples or in its parenteral formulation. The native fluorescence of CYZ has been investigated under various conditions. Different parameters affecting relative fluorescence intensity of CYZ including diluting solvent, surfactant, plasma protein solvent, and pH were studied and optimized. The linearity obtained between the fluorescence intensity at emission wavelength 350 nm after excitation at 244 nm and the corresponding CYZ concentrations was in the range 10-1000 ng/mL for measurement of CYZ either in pure form or in human plasma samples, with a appropriate correlation coefficient (r = 0.9999) and 3.10 ng/mL as the limit of detection and 9.41 ng/mL as the limit of quantitation. The suggested procedure was created and validated in accordance with ICH guidelines for quantification of CYZ either in its pure form or its dosage form, and FDA guidelines for the assay of CYZ in human plasma. Finally, in silico study and ADMET predictions were conducted for the studied drug impurities to estimate their pharmacokinetic behaviors. The results showed that both CYZ impurities have higher cellular permeability and maximum tolerated doses, DPM has higher BBB and CNS permeability than MPZ, while MPZ exceeds DPM in total clearance and volume of distribution.

Adoption of Advanced Chemometric Methods for Determination of Pyridoxine HCl, Cyclizine HCl, and Meclizine HCl in the Presence of Related Impurities: A Comparative Study.

BACKGROUND: Noising is an undesirable phenomenon accompanying the development of widely used chemometric models such as partial least square regression (PLSR) and support vector regression (SVR). OBJECTIVE: Optimizations of these chemometric models by applying orthogonal projection to latent structures (OPLS) as a preprocessing step which is characterized by canceling noise is the purpose of this research study. Additionally, a comprehensive comparative study between the developed methods was undertaken highlighting pros and cons. METHODS: OPLS was conducted with PLSR and SVR for quantitative determination of pyridoxine HCl, cyclizine HCl, and meclizine HCl in the presence of their related impurities. The training set was formed from 25 mixtures as there were five mixtures for each compound at each concentration level. Additionally, to check the validity and predictive ability of the developed chemometric models, independent test set mixtures were prepared by repeating the preparation of four mixtures of the training set plus preparation of another four independent mixtures. RESULTS: Upon application of the OPLS processing method, an upswing of the predictive abilities of PLSR and SVR was found. The root-mean-square error of prediction of the test set was the basic benchmark for comparison. CONCLUSION: The major finding from the conducted research is that processing with OPLS reinforces the ability of models to anticipate the future samples. HIGHLIGHTS: Novel optimizations of the widely used chemometric models; application of a comparative study between the suggested methods; application of OPLS preprocessing methods; quantitative determination of pyridoxine HCl, cyclizine HCl and meclizine HCl; checking the predictive power of developed chemometric models; analysis of active ingredients in their pharmaceutical dosage forms.

Fibrous myopathy induced by intramuscular injections of cyclizine.

A 63-year-old woman was referred to neurology with bilateral severe progressive pain and stiffness in her thighs. The patient had a 3-year history of injecting intramuscular cyclizine into the anterior thigh to treat nausea associated with a longstanding pan-enteric dysmotility syndrome. MRI of the thighs demonstrated fibrotic appearances. A biopsy of the left vastus lateralis and surrounding fascia identified pathology consistent with a fibrous myopathy. The patient was advised to stop intramuscular injections of cyclizine and undergo physiotherapy but she still remained in considerable pain. Although fibrous myopathy occurring as a consequence of recurrent intramuscular drug injections, particularly heroin, has been previously described, this is the first report of fibrous myopathy associated with the use of intramuscular cyclizine. We highlight this rare association and suggest that the long-term use of intramuscular cyclizine be avoided.

Disposition of Mianserin and Cyclizine in UGT2B10-Overexpressing Human Embryonic Kidney 293 Cells: Identification of UGT2B10 as a Novel N-Glucosidation Enzyme and Breast Cancer Resistance Protein as an N-Glucoside Transporter.

UDP-glucuronosyltransferases (UGTs) play an important role in the metabolism and detoxification of amine-containing chemicals; however, the disposition mechanisms for amines via UGT metabolism are not fully clear. We aimed to investigate a potential role of UGT2B10 in N-glucosidation and to determine the transporters for the excretion of N-glucosides. We first established a human embryonic kidney cell line 293 (HEK293) that stably overexpressed UGT2B10. Incubation of mianserin or cyclizine with the cells generated one N-glucuronide and one N-glucoside. Chemical inhibition (using specific chemical inhibitor Ko143) and biologic inhibition [using specific short hairpin RNA of breast cancer resistance protein (BCRP)] resulted in a significant reduction in efflux of N-glucuronide. Similar results were observed when multidrug resistance-associated protein (MRP4) was inhibited. Furthermore, inhibition of BCRP led to increased intracellular N-glucoside, whereas inhibition of MRP4 caused no changes in disposition of N-glucoside. Overall, the data indicated that BCRP, not MRP4, was responsible for the excretion of N-glucosides, whereas both BCRP and MRP4 contributed to excretion of N-glucuronides. Interestingly, downregulation of N-glucuronidation led to increased N-glucosidation in the cells, supporting the glucosidation as a potential complementary pathway for conventional glucuronidation. In conclusion, UGT2B10 was for the first time identified as an N-glucosidation enzyme. Generated N-glucosides were excreted primarily by the BCRP transporter.

[Cyclizine is sold in Denmark as an over-the-counter drug and has serious side effects when overdosed].

Cyclizine is sold in Denmark as an over-the-counter drug and affects not only histaminergic but also muscarinergic, serotonergic and α-adrenergic receptors, with side effects such as respiratory depression and cardiac arrhythmias, leading to fatalities. Due to the numerous side effects, it raises questions concerning the status of cyclizine as an over-the-counter drug. Data of healthcare contacts because of cyclizine intoxication in the 2014-2016 period should be analyzed to further illuminate the health risk of cyclizine poisoning.

Validated Analytical Methods for the Determination of Drugs Used in the Treatment of Hyperemesis Gravidarum in Multiple Formulations.

Quantitative multicomponent analysis is considered an analytical goal to save time and cost in analysis. Hence, this work aimed to provide sensitive and selective UV-spectrophotometric, chemometric manipulation, and ultra-performance LC (UPLC) methods for the determination of well-known coformulated antiemetics used in pregnancy, namely pyridoxine HCl (PYR), meclozine HCl, and cyclizine. The developed UV-spectrophotometric methods are dual wavelength in ratio spectra and first derivative of the ratio spectra with which PYR was determined selectively at 290.8 nm, whereas the other drugs in a ternary mixture were determined from their ratio spectra using a spectrum of PYR as a divisor in 0.1 M HCl. An ecofriendly partial least-squares regression chemometric method was applied to raw UV absorbance data for the determination of the ternary mixture in a 218-355 nm range using a three-factor, three-level design with water as the green solvent. A gradient UPLC method was developed and successfully resolved the ternary mixture within 5 min. Different ratios of water (adjusted to pH 3 with phosphoric acid) and methanol were delivered at 0.5 mL/min as the mobile phase into a Hypersil Gold C18 column (50 × 2.1 mm, 1.9 µm). The developed methods were successfully applied to different pharmaceutical formulations containing the aforementioned drugs and validated according to the International Conference on Harmonization guidelines. The results obtained were reproducible and reliable and can be applied for routine analysis and QC in laboratories.

Nicolau Syndrome (Embolia Cutis Medicamentosa): A Rare and Poorly Recognized Iatrogenic Cause of Cutaneous Thrombotic Vasculopathy.

Nicolau syndrome is a rare form of iatrogenic cutaneous necrosis which affects injection sites. Although classically associated with intramuscular injections, it may develop after subcutaneous or other routes of parenteral drug administration. Clinically, it manifests as necrotic ulcers that often develop in a background of erythematous and livedoid reticular patches. The histopathologic characteristics of Nicolau syndrome are poorly documented in the dermatopathology literature and features only rarely as one of the obscure causes of cutaneous thrombotic vasculopathy. We report a case of Nicolau syndrome developing secondary to subcutaneous injection of cyclizine to familiarize the clinicians and pathologists to this unusual condition. Given that it is potentially avoidable, pathologists should alert the clinicians to the possibility of Nicolau syndrome when a skin biopsy from an injection site shows signs of extensive thrombotic vasculopathy.

[Intentional suicide with cyclizine].

Cyclizine is an antihistamine with a sedative effect. In Denmark it is an over-the-counter drug, whereas it is a prescription drug in many other countries. It possesses anticholinergic and antiemetic properties, although the exact mechanism of action is unknown. At doses greater than 5 mg/kg potent side effects of anticholinergic character can be expected. This case report is a description of an intentional suicide with a dose greater than 70 mg/kg.

Validated Chromatographic Methods for the Analysis of Two Binary Mixtures Containing Pyridoxine Hydrochloride.

Accurate and precise TLC-densitometric and HPLC-diode-array detector (DAD) methods have been developed and validated to resolve two binary mixtures containing pyridoxine hydrochloride (PYH) with either cyclizine hydrochloride (CYH) or meclizine hydrochloride (MEH). In the developed TLC-densitometric method, chromatographic separation of the three studied drugs was carried out on silica gel 60 F254 plates using a developing system containing methylene chloride + acetone + methanol (7 + 1 + 0.5, v/v/v) scanning separated bands at 220 nm. Beer-Lambert law was obeyed in the ranges of 0.2-5, 0.2-4, and 0.2-4 µg/band for PYH, CYH, and MEH, respectively. On the other hand, the developed HPLC-DAD method depended on chromatographic separation on a Zorbax Eclipse C18 column using methanol-KH2PO4 (0.05 M; 90 + 10, v/v; pH 5, with H3PO4 and KOH) as the mobile phase, a flow rate of 1 mL/min, and UV scanning at 220 nm. A linear relationship was obtained between the integrated peak area and the concentration in the ranges of 10-50, 10-50, and 7-50 µg/mL for PYH, CYH, and MEH, respectively. The proposed methods were successfully applied for the determination of the cited drugs in their pharmaceutical formulations. Statistical comparison with the reported methods using Student's t- and F-tests found there were no significant differences between the proposed and reported methods for accuracy and precision.

Bioequivalence study of cyclizine hydrochloride 50 mg tablets in healthy volunteers: a randomized, open-label, single-dose study.

BACKGROUND: Cyclizine is used in the treatment and prevention of nausea and vomiting. We aimed to demonstrate bioequivalence between two formulations of cyclizine 50 mg tablets. METHODS/RESULTS: This single-dose, two-treatment, two-period, two-sequence, open-label, randomized crossover study was conducted on 32 healthy male volunteers. The average values for Cmax, Tmax, AUC0-t and AUC0-inf were 21.50 ng/ml, 3.85 h, 423.71 ng.h/ml and 489.26 ng.h/ml, for cyclizine 50 mg (test) versus 20.39 ng/ml, 4.34 h, 410.56 ng.h/ml and 473.86 ng.h/ml for Valoid 50 mg (reference). The 90% CI of the mean ratios of Cmax (geometric mean ratio: 101.81 ng/ml), and AUC0-t (101.81 ng.h/ml) were within the bioequivalence range of 80 to 125%. Both drugs were well tolerated. CONCLUSION: Cyclizine 50 mg is bioequivalent to the reference.

Continuous-Flow Multistep Synthesis of Cinnarizine, Cyclizine, and a Buclizine Derivative from Bulk Alcohols.

Cinnarizine, cyclizine, buclizine, and meclizine belong to a family of antihistamines that resemble each other in terms of a 1-diphenylmethylpiperazine moiety. We present the development of a four-step continuous process to generate the final antihistamines from bulk alcohols as the starting compounds. HCl is used to synthesize the intermediate chlorides in a short reaction time and excellent yields. This methodology offers an excellent way to synthesize intermediates to be used in drug synthesis. Inline separation allows the collection of pure products and their immediate consumption in the following steps. Overall isolated yields for cinnarizine, cyclizine, and a buclizine derivative are 82, 94, and 87 %, respectively. The total residence time for the four steps is 90 min with a productivity of 2 mmol h(-1) .

Suicide due to cyclizine overdose.

Cyclizine is an antihistamine with sedative effect used to treat motion sickness. A few studies have reported on cyclizine abuse among teenagers, and cyclizine abuse has been reported among opioid dependants receiving methadone, with the combination having been reported to produce strong psychoactive effects. Few reports exist on the possible toxic effects of cyclizine, and it is regarded as a safe drug most often sold as a non-prescription/over-the-counter drug. Very few cases of fatalities resulting from cyclizine overdose can be found in the literature. We present a case where a 22-year-old female was found unconscious and intoxication with drugs and alcohol was suspected. Whole blood from the femoral vein, urine and stomach content were collected during autopsy and screened for drugs of abuse and medicinal drugs. GC-MS screening of the stomach contents revealed presence of cyclizine and meclozine. Cyclizine and meclozine concentrations in blood were determined using a UPLC-MS-MS method. Quantification of femoral blood revealed a high concentration of cyclizine (16 mg/L), a low concentration of meclozine (0.2 mg/L) and ethanol 0.16 g/dL. No other medicinal drugs or drugs of abuse were detected. We report on a case of suicide where cyclizine was found to be the principal drug and question the safety of this drug.

Post-operative cyclizine misuse.

Cyclizine is commonly prescribed as an anti-emetic post-operatively. We report a case of a 51-year-old woman who developed addiction to intravenous cyclizine following regular administration at recommended doses. This is the first report of cyclizine misuse post-operatively. We compare this case to cyclizine abuse reported amongst other populations. Prescribers should be aware of the potential of cyclizine as a drug of abuse.