Cinnarizine: A Contemporary Review

Structural biology of voltage-gated calcium channels

Voltage-gated calcium (Cav) channels mediate Ca2+ influx in response to membrane depolarization, playing critical roles in diverse physiological processes. Dysfunction or aberrant regulation of Cav channels can lead to life-threatening consequences. Cav-targeting drugs have been clinically used to treat cardiovascular and neuronal disorders for several decades. This review aims to provide an account of recent developments in the structural dissection of Cav channels. High-resolution structures have significantly advanced our understanding of the working and disease mechanisms of Cav channels, shed light on the molecular basis for their modulation, and elucidated the modes of actions (MOAs) of representative drugs and toxins. The progress in structural studies of Cav channels lays the foundation for future drug discovery efforts targeting Cav channelopathies.

A comparative study on prophylactic efficacy of cinnarizine and amitriptyline in childhood migraine: a randomized double-blind clinical trial

BACKGROUND

Pediatric migraine prophylaxis is indicated when headaches are frequent and/or disabling. We aimed to conduct a study to compare the efficacy of cinnarizine and amitriptyline in pediatric migraine prophylaxis.

METHODS

In a randomized, double-blind trial, patients aged 4-17 years with migraine who were eligible for prophylaxis enrolled. The primary outcome was a reduction response rate of ≥50% with p < 0.005 with respect to headache characteristics. The secondary outcome was migraine disability assessment. We evaluated patients every four weeks for three months: T1: week 4, T2: week 8 and T3: week 12. The safety profile was also assessed.

RESULTS

Thirty patients were randomly assigned to each group. However, 43 patients completed the trial. Headache frequency decreased in amitriptyline group more effectively in T1 (p = 0.004). Amitriptyline was more successful in reducing the headache duration in all three periods (p < 0.005). There was no significant difference in severity improvement and reducing disability score between the two groups (p > 0.005). No serious adverse events were observed.

CONCLUSIONS

Both medications are effective in ameliorating migraine headaches and related disabilities. However, amitriptyline appears be a preferable option over cinnarizine, given its faster onset of action, efficacy in reducing headache duration and longer-lasting effects.Trial Registration: The study was registered with the Iranian Registry of Clinical Trials (IRCT) under the code IRCT-20191112045413N1.

In Operando Analysis of Milk-Based Oral Formulations during Digestion Using Synchrotron Small-Angle X-ray Scattering Coupled to Low-Frequency Raman Spectroscopy

A low-frequency Raman (LFR) probe was coupled to an in-line small-angle X-ray scattering (SAXS) beamline to test the capabilities of a combinatory approach for the determination of lipid and drug behavior during the enzymatic lipolysis of milk-based oral formulations. Cinnarizine was used as the model drug, and its solubilization dynamics as well as its potential impact on the supramolecular structures formed by the digestion products of bovine milk were evaluated from the perspective of both techniques. The SAXS data were superior in distinguishing various liquid crystalline assemblies formed during the digestion process, with LFR providing complementary information regarding the formation of calcium soaps. On the other hand, studying changes in the LFR domain allowed the differentiation of drug solubilization and precipitation; processes that were less clear from the X-ray scattering data. Given the relative simplicity of the combined experimental setup, these results highlight the advantages that the combination of the two techniques can provide for understanding and developing new lipid-based formulations and will help to translate the results obtained at synchrotron facilities to routine analysis procedures in laboratory/industry-based environments.

Anticholinergic Versus Antihistaminic Treatment for Simulator Sickness Prevention

Flight simulators have an essential role in aircrew training. Occasionally, symptoms of motion sickness, defined as simulator sickness, develop during these sessions. Preventive methods for motion sickness have been investigated thoroughly; however, only a few studies have examined preventive treatments for simulator sickness. The aim of this study was to examine the efficacy of scopolamine (an anticholinergic drug) compared with cinnarizine (an antihistaminic drug) for helicopter simulator sickness prevention. A validated simulator sickness questionnaire (SSQ) score was used to determine the severity of simulator sickness symptoms in this study. Preliminary SSQ scores and SSQ scores after each sortie were calculated. Each participant was given scopolamine, cinnarizine, or a placebo in a double-blind randomized manner before the first sortie of each training day. Forty-one helicopter pilots participated in the trial. The average age was 30.5 ± 7.1 years. SSQ values significantly improved from an average of 73.30 in the preliminary SSQ questionnaire to an average of 30.92 after 2 hours following the administration of cinnarizine (P = .012, 95%CI 8.071-76.703). Scopolamine was found to be less effective than both cinnarizine and the placebo in the alleviation of simulator sickness symptoms. This study is the first to compare scopolamine with cinnarizine for simulator sickness prevention. Based on the results of this study, we recommend the use of cinnarizine over scopolamine for simulator sickness prevention.

Analytical Quality by Design-Driven RP-HPLC Method Conditions to Concomitantly Determine Cinnarizine and Morin Hydrate in Combined Drug Solution and Dual Drug-Loaded Formulations

BACKGROUND

The replacement of traditional oils with a camphor and menthol-based eutectic mixture is done to prepare oil-less emulsion-like dispersions for co-delivery of cinnarizine (CNZ) and morin hydrate (MH) for managing Meniére's disease (MD). Since two drugs are loaded into the dispersions, the development of a suitable reverse phase-high performance liquid chromatography (RP-HPLC) method for their simultaneous analysis becomes inevitable.

OBJECTIVE

By applying the analytical quality by design (AQbD) approach, the RP-HPLC method conditions were optimized for the concomitant determination of two drugs.

METHODS

The systematic AQbD started with identifying critical method attributes (CMA) through an Ishikawa fishbone diagram, risk estimation matrix, and risk priority number-based failure mode effect analysis followed by screening using fractional factorial design and optimization by face-centered central composite design. The concomitant determination of two drugs by the optimized RP-HPLC method condition was substantiated via specificity checking using combined drug solution, drug entrapment efficiency, and in vitro release of the two drugs from emulsion-like dispersions.

RESULTS

The AQbD optimized RP-HPLC method conditions revealed the retention time for CNZ and MH at 5.017 and 5.323, respectively. The studied validation parameters were found within the ICH-prescribed limits. Exposing the individual drug solutions to acidic and basic hydrolytic conditions yielded extra chromatographic peaks for MH, probably due to the degradation of MH. The DEE % values of 87.40 ± 4.70 and 74.79 ± 2.94, respectively, were noticed for CNZ and MH in emulsion-like dispersions. More than 98% CNZ and MH release was occurred from emulsion-like dispersions within 30 min post-dissolution in artificial perilymph.

CONCLUSIONS

Overall, the AQbD approach could be helpful for systematic optimization of RP-HPLC method conditions to estimate concomitantly other therapeutic moieties.

HIGHLIGHTS

The proposed article shows the successful application of AQbD for the optimization of RP-HPLC method conditions to concomitantly estimate CNZ and MH in combined drug solution and dual-drug-loaded emulsion-like dispersions.

Nutritional and Behavioral Countermeasures as Medication Approaches to Relieve Motion Sickness: A Comprehensive Review

The mismatch in signals perceived by the vestibular and visual systems to the brain, also referred to as motion sickness syndrome, has been diagnosed as a challenging condition with no clear mechanism. Motion sickness causes undesirable symptoms during travel and in virtual environments that affect people negatively. Treatments are directed toward reducing conflicting sensory inputs, accelerating the process of adaptation, and controlling nausea and vomiting. The long-term use of current medications is often hindered by their various side effects. Hence, this review aims to identify non-pharmacological strategies that can be employed to reduce or prevent motion sickness in both real and virtual environments. Research suggests that activation of the parasympathetic nervous system using pleasant music and diaphragmatic breathing can help alleviate symptoms of motion sickness. Certain micronutrients such as hesperidin, menthol, vitamin C, and gingerol were shown to have a positive impact on alleviating motion sickness. However, the effects of macronutrients are more complex and can be influenced by factors such as the food matrix and composition. Herbal dietary formulations such as Tianxian and Tamzin were shown to be as effective as medications. Therefore, nutritional interventions along with behavioral countermeasures could be considered as inexpensive and simple approaches to mitigate motion sickness. Finally, we discussed possible mechanisms underlying these interventions, the most significant limitations, research gaps, and future research directions for motion sickness.

RP-HPLC-Based Bioanalytical Approach for Simultaneous Quantitation of Cinnarizine and Domperidone in Rat Plasma

An accurate, precise and sensitive reverse-phase high-performance liquid chromatography (RP-HPLC) bioanalytical approach was developed for the simultaneous estimation of cinnarizine (CIN) and domperidone (DOM) in rat plasma using irbesartan (IRB) as an internal standard (IS). The proposed RP-HPLC approach was validated as per the latest ICH M10 guidelines. The analytes (CIN and DOM) and IS were extracted from plasma samples using the protein precipitation strategy. Chromatographic separation is accomplished by a C18 SunfireTM (5 µm, 250 mm × 4.6 mm) analytical column, using an isocratic mobile phase consisting of acetonitrile-methanol in 30:70 proportions at a flow rate of 1 mL/min. The detection of all three constituents was recorded at a wavelength of 270 nm with a UV detector. DOM, CIN and IS were eluted at 3.2, 4.5 and 6.1 min, respectively, utilizing a total run time of 10 min. The lower limit of quantification (LLOQ) was 5 ng/mL for CIN and DOM in rat plasma. The proposed RP-HPLC approach was linear in the 5–200 ng/mL range for CIN and DOM. The recovery of the method was greater than 95%, and the relative uncertainty was less than 2%, indicating that the proposed bioanalytical approach was accurate and precise. The limit of detection was established as 1.1 ng/mL for CIN and 1.7 ng/mL for DOM. The created approach was found to be robust and passed all validation criteria; thus, the proposed RP-HPLC approach can be employed successfully for the simultaneous assessment of CIN and DOM in rat plasma.

Effectiveness of non-pharmacological treatments for vestibular and oculomotor dysfunction in patients with persistent post-concussive symptoms: protocol for a systematic review and meta-analysis

INTRODUCTION

Concussion is a form of mild traumatic brain injury that disrupts brain function. Although symptoms are mostly transient, recovery can be delayed and result in persistent postconcussive symptoms (PPCS). Vestibular and oculomotor dysfunction are among the most debilitating impairments associated with PPCS. However, pharmacological interventions for these impairments are associated with deleterious side effects. Accordingly, increasing research has examined the utility of non-pharmacological interventions for PPCS. The aim of this review is to synthesise and evaluate the effectiveness of non-pharmacological interventions for the treatment of vestibular and oculomotor dysfunction for patients with PPCS.

METHODS AND ANALYSIS

Systematic searches of MEDLINE, PubMed, Web of Science and Scopus will identify randomised controlled trials employing non-pharmacological treatments for vestibular and/or oculomotor dysfunction for PPCS. Such interventions may include, but are not limited to, vestibular rehabilitation, optokinetic stimulation and vestibulo-ocular reflex exercises. Assessments of oculomotor function will include versional eye movements, vergence eye movements, visual-fixation movements and accommodation response. Assessments of vestibular function will include the Fukuda Step test, functional balance tests, force displacement tests, and subjective reports of balance disruption or vertigo. Where appropriate, meta-analyses of standardised mean differences will be conducted using a random effects model for continuous outcomes. For dichotomous outcomes (improved vs not improved following treatment), effects will be expressed as relative risk. The impact of heterogeneity will be calculated using the I² statistic. The Physiotherapy Evidence Database scale will be used to determine the methodological quality of individual studies and Grading of Recommendations, Assessment, Development and Evaluations used to assess the certainty and quality of evidence for each outcome.

ETHICS AND DISSEMINATION

Ethical approval is not required for this review. Findings will be disseminated through peer-reviewed publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021254720.

Migraine Pharmacological Treatment and Cognitive Impairment: Risks and Benefits

Migraine is a common neurological disorder impairing the quality of life of patients. The condition requires, as an acute or prophylactic line of intervention, the frequent use of drugs acting on the central nervous system (CNS). The long-term impact of these medications on cognition and neurodegeneration has never been consistently assessed. The paper reviews pharmacological migraine treatments and discusses their biological and clinical effects on the CNS. The different anti-migraine drugs show distinct profiles concerning neurodegeneration and the risk of cognitive deficits. These features should be carefully evaluated when prescribing a pharmacological treatment as many migraineurs are of scholar or working age and their performances may be affected by drug misuse. Thus, a reconsideration of therapy guidelines is warranted. Furthermore, since conflicting results have emerged in the relationship between migraine and dementia, future studies must consider present and past pharmacological regimens as potential confounding factors.

Drug-Drug Interactions in Vestibular Diseases, Clinical Problems, and Medico-Legal Implications

Peripheral vestibular disease can be treated with several approaches (e.g., maneuvers, surgery, or medical approach). Comorbidity is common in elderly patients, so polytherapy is used, but it can generate the development of drug-drug interactions (DDIs) that play a role in both adverse drug reactions and reduced adherence. For this reason, they need a complex kind of approach, considering all their individual characteristics. Physicians must be able to prescribe and deprescribe drugs based on a solid knowledge of pharmacokinetics, pharmacodynamics, and clinical indications. Moreover, full information is required to reach a real therapeutic alliance, to improve the safety of care and reduce possible malpractice claims related to drug-drug interactions. In this review, using PubMed, Embase, and Cochrane library, we searched articles published until 30 August 2021, and described both pharmacokinetic and pharmacodynamic DDIs in patients with vestibular disorders, focusing the interest on their clinical implications and on risk management strategies.

Efficacy and Pharmacological Appropriateness of Cinnarizine and Dimenhydrinate in the Treatment of Vertigo and Related Symptoms

Vertigo is not itself a disease, but rather a symptom of various syndromes and disorders that jeopardize balance function, which is essential for daily activities. It is an abnormal sensation of motion that usually occurs in the absence of motion, or when a motion is sensed inaccurately. Due to the complexity of the etiopathogenesis of vertigo, many pharmacological treatments have been tested for efficacy on vertigo. Among these drugs, cinnarizine, usually given together with dimenhydrinate, appears to be the first-line pharmacotherapy for the management of vertigo and inner ear disorders. Based on these considerations, the present non-interventional study aimed to investigate the clinical efficacy and tolerability of a fixed combination of cinnarizine (20 mg) and dimenhydrinate (40 mg) in patients suffering from vertigo-related symptoms. To this end, we enrolled 120 adults-70 males, and 50 females-with an average age of 64 years. Before beginning pharmacological treatment, all patients were screened for the intensity of vertigo, dizziness, and concomitant symptoms through the Visual Scale of Dizziness Disorders and Dizziness Handicap Inventory scales. At the end of the anamnestic evaluation, patients received the fixed-dose combination of cinnarizine (20 mg) plus dimenhydrinate (40 mg) 3 times daily, for 60 days. The results of this study provide further insight regarding the efficacy of the fixed combination when used to reduce symptoms of vestibular vertigo of central and/or peripheral origin, after both the 15- and 60-day therapies. Independent of the type of vertigo, the fixed combination was able to reduce dizziness- and vertigo-associated symptoms in more than 75% of all patients treated, starting from 15 days of therapy, and improving 60 days after starting the therapy. Interestingly, we also found differences between male and female patients in the framework of the pharmacological effects of therapy. This study provides further details concerning the therapeutic efficacy of the fixed combination of cinnarizine and dimenhydrinate, and also focuses attention on the possibility that these drugs could act in a gender-specific manner, paving the way for further research.

Cinnarizine- and flunarizine-associated movement disorder: a literature review

Introduction

Cinnarizine (CNZ) and flunarizine (FNZ) belong to the calcium channel blockers class of medication.

Main text

The aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of CNZ/FNZ-associated movement disorder (MD). Relevant reports in six databases were identified and assessed by two reviewers without language restriction. One hundred and seventeen reports containing 1920 individuals who developed a CNZ/FNZ-associated MD were identified. The MD encountered were 1251 parkinsonism, 23 dyskinesias, 11 akathisia, 16 dystonia, and 5 myoclonus, and in the group not clearly defined, 592 extrapyramidal symptoms, 19 tremors, 2 bradykinesia, and 1 myokymia. The predominant sex was female with a percentage of 72.69% (466/641). The mean age was 74.49 (SD, 7.88) years. The mean CNZ dose was 148.19 mg (SD, 42.51) and for the FNZ dose, 11.22 mg (5.39). The mean MD onset and recovery were 1.83 years (SD, 1.35) and 3.71 months (SD, 1.26). In the subgroup of subjects that had improvement of the symptoms, the complete recovery was achieved within 6 months of the drug withdrawal in almost all subjects (99%). The most common management was drug withdrawal. A complete recovery was observed in 93.77% of the patients (437/466).

Conclusions

CNZ/FNZ-associated MD was extensively reported in the literature. Parkinsonism was the most well described. Myoclonus (MCL) was the poorest described MD with missing data about the neurological examination and electrodiagnostic studies. The knowledge of this disorder probably can contribute to the understanding of the other drug-induced MDs.

Formulation and Characterization of Cinnarizine Targeted Aural Transfersomal Gel for Vertigo Treatment: A Pharmacokinetic Study on Rabbits

INTRODUCTION AND AIM

Cinnarizine is indicated orally for treating vertigo associated with Ménière's syndrome and has a local anesthetic effect as well. The present study aims to develop an aural Cinnarizine mucoadhesive transfersomal gel to overcome the first-pass metabolism.

METHODS

Eighteen Cinnarizine transfersomes were prepared by the thin-film hydration technique using different types of phosphatidylcholine and edge activators in different ratios. Formulae were tested for their appearance, entrapment efficiency, and in-vitro drug release after eight hours. F1, F4, F7, F9, F10, and F12 were selected to be examined for particle size, polydispersity index, and zeta potential. According to the previous parameters, F1 and F10 were incorporated into gels using different polymers according to factorial design 23. The eight gels were tested for appearance, pH, mucoadhesion, spreadability, drug content, in-vitro drug release after eight hours, and rheology. The transfersomal gel F1A was subjected to FTIR analysis and in-vivo pharmacokinetic study.

RESULTS

The transfersomal dispersion colors were ranging between the white and yellow. Their EE % ranged from 64.36±1.985% to 94.09±1.74%, and their in-vitro release percentages were between 61.82±1.92% and 95.92±1.18%. Also, the vesicles PS ranged from 212.3±30.05nm to 2150±35.35nm, DI from 0.238±0.134 to 1±0.00 and zeta potential from -57.5±2.54 to +4.73±1.57 mV. The transfersomal gels showed pseudoplastic behavior, pH range of 5.5 to 8, a mucoadhesive force of 169.188±1.26 to 321.212±6.94 (dyne/cm2×102), spreadability of 40 ±7.03mm to 138 ±3.77mm, and in-vitro drug release of 81.63±1.128% to 97.78±0.102%. The IR spectra of the (drug-excipients) physical mixture revealed that there were no shifts of incompatibility. The in-vivo pharmacokinetic study illustrated that [AUC]0-24 of F1A was significantly higher than that of tablets at (P< 0.05), equivalent to 703.563±26.470 and 494.256±9.621ɲg.hr/mL respectively.

CONCLUSION

The study revealed that Cinnarizine aural mucoadhesive targeted delivery provides an improved systemic bioavailability over the conventional oral route.

Simultaneous estimation of dimenhydrinate, cinnarizine and their toxic impurities benzophenone and diphenylmethylpiperazine; in silico toxicity profiling of impurities

The British Pharmacopeia (BP) reported that the carcinogenic and hepatotoxic, benzophenone (BZP) is a dimenhydrinate (DMH) impurity. On the other hand, cinnarizine (CIN) is reported to have five impurities (A–E). The toxicity profile of CIN impurities was studied and the in silico data revealed that impurity A [1-(diphenylmethyl)piperazine] (DPP) was the most toxic CIN impurity, and hence it was selected during this work. TLC-densitometric method was developed for separation and simultaneous quantitation of DMH, CIN and their toxic impurities. In the proposed method hexane : ethanol : acetone : glacial acetic acid (7 : 3 : 0.7 : 0.5, by volume) with UV scanning at 225 nm were used. Method validation was carried out according to ICH guidelines and linearity was achieved in the range 0.2–4, 0.5–5, 0.1–2.0, and 0.05–2.2 μg per band for DMH, CIN, BZP and DPP, respectively. On the application of the method to pharmaceutical formulation, no interference from additives was observed. The greenness of the method was evaluated using the analytical eco-scale and the results revealed the low negative environmental impact of the developed method.

TLC-densitometric analysis of dimenhydrinate, cinnarizine and their highly toxic impurities.