A fixed combination of cinnarizine/dimenhydrinate for the treatment of patients with acute vertigo due to vestibular disorders : a randomized, reference-controlled clinical study

Efficacy and Safety of a Fixed-Dose Combination of Cinnarizine 20 mg and Dimenhydrinate 40 mg in the Treatment of Patients with Vestibular Vertigo: An Individual Patient Data Meta-Analysis of Randomised, Double-Blind, Controlled Clinical Trials

Background and Objective

The source data of four individual randomised, double-blind, reference- and/or placebo-controlled clinical trials with virtually identical study design were pooled for the present meta-analysis. The main objective was to further evaluate the efficacy and safety of the fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg in comparison to various other antivertigo treatments in patients suffering from central and/or peripheral vestibular vertigo.

Methods

Adult male and female outpatients were subjected to a 4-week treatment with the fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg, cinnarizine (20 mg, 50 mg), dimenhydrinate (40 mg, 100 mg), betahistine dimesylate (12 mg), betahistine dihydrochloride (16 mg) and placebo, respectively. The primary efficacy endpoint was the reduction of a validated mean vertigo score (MVS), a composite score of 12 individual vertigo symptoms, the intensities of which were each evaluated by the patients on a 5-point visual analogue scale. For analysis of primary and further secondary efficacy endpoints, baseline-adjusted analysis of covariance (ANCOVA) was used to calculate adjusted least squares means (LSM) with associated two-sided 95% confidence intervals (CIs) for the difference in MVS reductions between treatment groups. Moreover, various sensitivity analyses, responder and subgroup analyses as well as descriptive analyses with respect to safety/tolerability of the treatments were conducted.

Results

Of 795 randomised patients, 779 belonged to the intent-to treat (ITT) and 723 to the per-protocol (PP) population. The main efficacy analysis was based on the ITT population (mean age 52.1 years, 61% female). The mean decrease of the MVS from baseline to Week 4 in the cinnarizine/dimenhydrinate group (−1.10) proved to be significantly larger than in any of the comparator groups. LSM differences for comparators versus the fixed combination ranged between 0.16 (95% confidence interval (CI) 0.03; 0.30, p = 0.017) for cinnarizine 20 mg and 0.60 (95% CI 0.42; 0.78; p < 0.001) for betahistine dimesylate 12 mg in favour of the fixed combination. Furthermore, after 4 weeks of treatment, 74 patients (24.7%) in the cinnarizine/dimenhydrinate group were completely symptom free (MVS = 0), a significantly greater proportion than in any of the comparator groups. Sensitivity analyses showed that baseline characteristics such as age, sex, duration of vertigo and antivertigo pretreatment had only a very minor and clinically non-relevant impact on the efficacy results regarding the primary efficacy outcome. Subgroup analyses with respect to age groups (< 65 years/≥ 65 years) and sex showed no significant differences in efficacy within any of the treatment groups. All treatments were well tolerated. A total of 55 patients (6.9%) reported 75 non-serious adverse events (AEs), and 19 patients (2.4%) discontinued the study prematurely because of AEs. Nearly 95% of the patients (cinnarizine/dimenhydrinate group: 97.9%) rated the tolerability of the study medications as either “good” or “very good”.

Conclusion

The findings of the present meta-analysis indicate that the fixed combination of cinnarizine and dimenhydrinate is a safe and potentially superior treatment option for patients suffering from central and/or peripheral vestibular vertigo, as compared to current standard treatments such as cinnarizine, dimenhydrinate or betahistine given alone in monotherapy.

Current and Emerging Medical Therapies for Dizziness

Medical therapies for dizziness are aimed at vertigo reduction, secondary symptom management, or the root cause of the pathologic process. Acute peripheral vertigo pharmacotherapies include antihistamines, calcium channel blockers, and benzodiazepines. Prophylactic pharmacotherapies vary between causes. For Meniere disease, betahistine and diuretics remain initial first-line oral options, whereas intratympanic steroids and intratympanic gentamicin are reserved for uncontrolled symptoms. For cerebellar dizziness and oculomotor disorders, 4-aminopyridine may provide benefit. For vestibular migraine, persistent postural perceptual dizziness and mal de débarquement, treatment options overlap and include selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants and calcium channel blockers.

Current Insights into Treating Vertigo in Older Adults

The number of older people has been increasing over recent decades in Western populations. Dizziness, imbalance, and vertigo constitute some of the most common complaints in older patients, and risk of falling is the most frequent and worrying consequence. It has been reported that 15–20% of the adult population experiences these debilitating symptoms. Among the diseases that may be associated with vertigo, the three classes of otological, central, and functional (psychological) dizziness may be distinguished. Overall, vestibular disorders account for 48% of vertiginous complaints in the older population. The main focus of this article is to review the forms of pharmacotherapy for vertigo, especially with regard to older patients, who may be treated simultaneously with other drugs for different comorbidities. Interactions with other drugs should be considered in the choice of a particular course of treatment. Moreover, overuse of pharmacotherapy for the management of vertigo in the elderly may prevent the development of the central compensatory mechanism that sustains both static and dynamic imbalance after a vertiginous crisis. In the majority of patients, vestibular and physical rehabilitation are strongly advised and rarely contraindicated.

Meniere's disease: Medical management, rationale for vestibular preservation and suggested protocol in medical failure

Meniere's disease is a peripheral audiovestibular disorder characterized by vertigo, hearing loss, tinnitus, and aural fullness. Management of these symptoms includes medical and surgical treatment. Many patients with Meniere's disease can be managed using nonablative therapy, such as intratympanic steroids and endolymphatic shunt surgery, prior to ablative techniques such as intratympanic gentamicin. Recognition of concurrent migraine symptoms may aid in medical therapy and also underscore the importance of preserving vestibular function where possible. The goal of this review is to explain the importance of nonablative therapy options and discuss treatment protocols after medical failure.

Comparison of efficacy dimenhydrinate and metoclopramide in the treatment of nausea due to vertigo; a randomized study

BACKGROUND

This study aimed to compare the therapeutic efficacy of dimenhydrinate and metoclopramide in patients with nausea and vertigo.

METHODS

A prospective, double-blind, randomized clinical trial was performed on patients who presented to the emergency department (ED) with nausea and vertigo in the six month period between Nov 1st 2012 and May 1st 2013. Adult patients who were 18 to 65 years old presenting to the ED with nausea and vertigo or motion sickness were included in the study. A total of 200 patients were divided into 2 groups who were admitted to ED with complaints of vertigo accompanied by nausea. In the first group, 50 mg dimenhydrinate and 10 mg metoclopramide infusions were given intravenously for 15 min. The efficacy of treatment was measured by using a 10 mm Visual Analog Scale (VAS) performed at 0, 15 and the 30th minute. The primary outcome variable was a reduction in vertigo intensity documented on the VAS at the 30th minute after medication administration.

RESULTS

A total of 200 patients were included in the randomization (n=100 in both groups). The baseline vertigo VAS scores were 7.57±1.42 in the dimenhydrinate (DMT) group and 7.27±1.40 in the metoclopramide (MTP) group (p=0.09). In the 30th minute of treatment, the average vertigo VAS score was 2.46 ± 2.39 in the DMT group and 2.31±1.96 in the MTP group; no significant differences were detected between groups. The baseline nausea VAS scores were 7.62±1.48 in the DMT group and 7.45±1.27 in the MTP group (p=0.36). In the 30th minute of treatment the average vertigo VAS score decreased to 2.27±2.24 in the DMT group and 2.70±2.48 in the MTP group, no significant differences were detected between groups. No significant differences were detected between nausea VAS changes and vertigo VAS changes at 30th minutes of the treatment (p=0.06, p=0.85 respectively). Rescue medication need was similar in both treatment groups (p=0.94). No significant differences were detected about the side effects which are sedation (p=0.56) and hypotension (p=0.57).

CONCLUSIONS

In conclusion, this prospective, double-blind, randomized study showed that both DMT and MTP have similar efficacy in reducing nausea and vertigo symptoms in the ED.

Clinical Practice Guideline: Ménière's Disease

OBJECTIVE

Ménière's disease (MD) is a clinical condition defined by spontaneous vertigo attacks (each lasting 20 minutes to 12 hours) with documented low- to midfrequency sensorineural hearing loss in the affected ear before, during, or after one of the episodes of vertigo. It also presents with fluctuating aural symptoms (hearing loss, tinnitus, or ear fullness) in the affected ear. The underlying etiology of MD is not completely clear, yet it has been associated with inner ear fluid (endolymph) volume increases, culminating in episodic ear symptoms (vertigo, fluctuating hearing loss, tinnitus, and aural fullness). Physical examination findings are often unremarkable, and audiometric testing may or may not show low- to midfrequency sensorineural hearing loss. Conventional imaging, if performed, is also typically normal. The goals of MD treatment are to prevent or reduce vertigo severity and frequency; relieve or prevent hearing loss, tinnitus, and aural fullness; and improve quality of life. Treatment approaches to MD are many and typically include modifications of lifestyle factors (eg, diet) and medical, surgical, or a combination of therapies.

PURPOSE

The primary purpose of this clinical practice guideline is to improve the quality of the diagnostic workup and treatment outcomes of MD. To achieve this purpose, the goals of this guideline are to use the best available published scientific and/or clinical evidence to enhance diagnostic accuracy and appropriate therapeutic interventions (medical and surgical) while reducing unindicated diagnostic testing and/or imaging.

Efficacy and Safety of a Fixed Combination of Cinnarizine 20 mg and Dimenhydrinate 40 mg vs Betahistine Dihydrochloride 16 mg in Patients with Peripheral Vestibular Vertigo: A Prospective, Multinational, Multicenter, Double-Blind, Randomized, Non-inferiority Clinical Trial

Background and Objective

Vertigo derived from peripheral vestibular disorders is quite frequently encountered in daily clinical practice and can be a severely disabling symptom associated with substantial impairment of health-related quality of life for the affected patients. Betahistine, a structural analogue of histamine and presumably the most widely prescribed anti-vertigo drug worldwide, has previously been shown to be an effective and safe treatment for these patients. The objective of the present study was to evaluate whether the fixed combination of cinnarizine and dimenhydrinate (Arlevert^®) is non-inferior and thus a potentially useful alternative to betahistine dihydrochloride in the treatment of patients suffering from peripheral vestibular vertigo.

Methods

In this prospective, multicenter, double-blind, randomized, non-inferiority clinical trial, outpatients from 8 ENT clinics in Austria, Bulgaria, the Czech Republic and Russia were randomly assigned to receive three times daily one tablet of either the fixed combination cinnarizine 20 mg/dimenhydrinate 40 mg or betahistine dihydrochloride 16 mg for 4 weeks. Primary endpoint was the reduction of the mean vertigo score (MVS), a validated 12-item composite score defined as the mean of 6 vertigo symptoms (dystasia and walking unsteadiness, staggering, rotary sensation, tendency to fall, lift sensation, blackout) and 6 trigger factors for vertigo (change of position, bowing, getting up, driving by car/train, head movements, eye movement), after 4 weeks of therapy, as judged by the patient on a 5-point visual analogue scale (VAS). The non-inferiority margin was set to 0.3. Secondary outcomes included the patient’s and investigator’s judgment of global efficacy, the patient’s rating of impairment of daily activities, and safety/tolerability of the treatments.

Results

Three hundred and six patients (mean age 53.5 years, approximately 60% female) were enrolled and randomized to the fixed combination cinnarizine/dimenhydrinate (n = 152) or betahistine (n = 154) groups; 297 patients completed the study and 294 (146 and 148, respectively) were valid for the per-protocol analysis, which was used for the non-inferiority analysis. Treatment with cinnarizine/dimenhydrinate led to a stronger reduction of the MVS [least squares mean (LSM)] after 4-week therapy (primary endpoint) in comparison to betahistine (0.395 vs 0.488; difference: − 0.093, 95% CI − 0.180; − 0.007, p = 0.035); since the upper limit of the two-sided 95% confidence interval was not only below the non-inferiority margin of 0.3, but also entirely below 0, superiority of the fixed combination could be demonstrated. The combination preparation was also more effective after 1 week of therapy and received more favorable patient’s ratings on overall efficacy and impairment of daily activities. Both treatments were very well tolerated. Only 12 patients (3.92%) reported 13 non-serious adverse events; 2 cinnarizine/dimenhydrinate-treated patients discontinued the study prematurely due to adverse events as compared to 5 betahistine-treated patients.

Conclusion

The fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg was found to be not only non-inferior, but superior to betahistine 16 mg in the improvement of peripheral vestibular vertigo. Furthermore, taking into account a good and slightly favorable safety profile, the present study provides evidence that the fixed-combination preparation is a potent and even superior alternative to betahistine in the treatment of vertigo related to peripheral vestibular disorders.

Study Registration

EudraCT No. 2011-004025-27.

Management of peripheral vertigo with antihistamines: New options on the horizon

Vertigo is associated with a wide range of vestibular pathologies. It increasingly affects the elderly, with a high cost to society. Solutions include vestibular suppressants and vestibular rehabilitation, which form the mainstay of therapy. Antihistamines represent the largest class of agents used to combat vestibular vertigo symptoms. Agents targeting the H₁ and H₃ receptors have been in clinical use for several decades as single agents. Nonetheless, effective management of vertigo proves elusive as many treatments largely address only associated symptoms, and with questionable efficacy. Additionally, the primary and limiting side effect of sedation is counterproductive to normal functioning and the natural recovery process occurring via central compensation. To address these issues, the timing of administration of betahistine, the mainstay H₃ antihistamine, can be fine-tuned, while bioavailability is also being improved. Other approaches include antihistamine combination studies, devices, physical therapy and behavioural interventions. Recently demonstrated expression of H₄ receptors in the peripheral vestibular system represents a new potential drug target for treating vestibular disorders. A number of novel selective H₄ antagonists are active in vestibular models in vivo. The preclinical potential of SENS-111 (Seliforant), an oral first-in-class selective H₄ antagonist is the only such molecule to date to be translated into the clinical setting. With an excellent safety profile and notable absence of sedation, encouraging outcomes in an induced vertigo model in healthy volunteers have led to ongoing clinical studies in acute unilateral vestibulopathy, with the hope that H₄ antagonists will offer new effective therapeutic options to patients suffering from vertigo.

The Neurophysiology and Treatment of Motion Sickness

BACKGROUND

Seasickness and travel sickness are classic types of motion illness. Modern simulation systems and virtual reality representations can also induce comparable symptoms. Such manifestations can be alleviated or prevented by various measures.

METHODS

This review is based on pertinent publications retrieved by a PubMed search, with special attention to clinical trials and review articles.

RESULTS

Individuals vary in their susceptibility to autonomic symptoms, ranging from fatigue to massive vomiting, induced by passive movement at relatively low frequencies (0.2 to 0.4 Hz) in situations without any visual reference to the horizontal plane. Younger persons and women are considered more susceptible, and twin studies have revealed a genetic component as well. The various types of motion sickness are adequately explained by the intersensory conflict model, incorporating the vestibular, visual, and proprioceptive systems and extended to include consideration of postural instability and asymmetry of the otolith organs. Scopolamine and H1-antihistamines, such as dimenhydrinate and cinnarizine, can be used as pharmacotherapy. The symptoms can also be alleviated by habituation through long exposure or by the diminution of vestibular stimuli.

CONCLUSION

The various types of motion sickness can be treated with general measures to lessen the intersensory conflict, behavioral changes, and drugs.

Can a Traditional Korean Manual Therapy Be a Complementary and Alternative Strategy for Cervicogenic Dizziness? A Study Protocol for a Randomized Controlled Trial

Cervicogenic dizziness is dizziness triggered by movement or positioning of the cervical spine and is often accompanied by neck pain or stiffness. This is a prospective, pragmatic, assessor-blind, randomized controlled trial aimed at testing the efficacy and safety of adjuvant Chuna Manual Therapy (CMT) in patients with cervicogenic dizziness under usual care treatments. Fifty patients with cervicogenic dizziness will be randomly allocated to CMT or usual care (UC) groups in a 1 : 1 ratio. Extensive screening procedures, including examinations for central nervous system problems and nystagmus, will be applied to exclude other dizziness-inducing disorders. The eligible participants will receive 12 sessions of CMT plus UC or only UC over 6 weeks. CMT includes mandatory and discretionary techniques, whereas UC includes electrotherapy, thermotherapy, and patient education. The efficacy will be evaluated primarily as Dizziness Handicap Inventory score. The severity and frequency of dizziness, the level of neck pain or stiffness, and the cervical range of motion will also be evaluated. Safety will be assessed by adverse events. The data will be statistically analyzed at p < 0.05. Trial Registration. This trial was registered with Clinical Research Information Service (CRIS) in Korea, KCT0002565, on 29 November 2017, https://cris.nih.go.kr/cris/search/search_result_st01_kren.jsp?seq=9610<ype=&rtype=.

A Herbal Medicine, Gongjindan, in Subjects with Chronic Dizziness (GOODNESS Study): Study Protocol for a Prospective, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Clinical Trial for Effectiveness, Safety, and Cost-Effectiveness

This study protocol aims to explore the effectiveness, safety, and cost-effectiveness of a herbal medication, Gongjindan (GJD), in patients with chronic dizziness. This will be a prospective, multicenter, randomized, double-blind, placebo-controlled, parallel-group, clinical trial. Seventy-eight patients diagnosed with Meniere's disease, psychogenic dizziness, or dizziness of unknown cause will be randomized and allocated to either a GJD or a placebo group in a 1 : 1 ratio. Participants will be orally given 3.75 g GJD or placebo in pill form once a day for 56 days. The primary outcome measure will be the Dizziness Handicap Inventory score. Secondary outcome measures will be as follows: severity (mean vertigo scale and visual analogue scale) and frequency of dizziness, balance function (Berg Balance Scale), fatigue (Fatigue Severity Scale) and deficiency pattern/syndrome (qi blood yin yang-deficiency questionnaire) levels, and depression (Korean version of Beck's Depression Inventory) and anxiety (State-Trait Anxiety Inventory) levels. To assess safety, adverse events, including laboratory test results, will be monitored. Further, the incremental cost-effectiveness ratio will be calculated based on quality-adjusted life years (from the EuroQoL five dimensions' questionnaire) and medical expenses. Data will be statistically analyzed at a significance level of 0.05 (two-sided). This trial is registered with ClinicalTrials.gov NCT03219515, in July 2017.

Cinnarizine: A Contemporary Review

Cinnarizine, is approved for nausea, vomiting, motion sickness, inner ear disorders and is considered as first-line pharmacotherapy for management of vertigo. It acts by anti-vasoconstrictor activity, reducing blood viscosity and reducing nystagmus in labyrinth. Lack of adequate literature on clinical evidence of cinnarizine and its combination (dimenhydrinate) in vertigo management prompted this review. A specific MEDLINE literature search strategy was designed combining Medical Subject Headings, free-text keywords (like cinnarizine and vertigo) using Boolean operators (1970-2016) for clinical studies, clinical reviews and meta-analyses of cinnarizine. Analyses of studies validated cinnarizine's efficacy in peripheral and central vertigo versus placebo or other therapies, and was well-tolerated by the patients recruited across different studies. Cinnarizine and/ or its combinations are favorable in management of vestibular disorders wherein cinnarizine acts predominantly peripherally on labyrinth and dimenhydrinate acts centrally on vestibular nuclei and associated centers in brainstem. Combination therapy of cinnarizine and/ or its combinations demonstrated a better safety profile than either of the mono-components, offering a viable therapeutic option in vertigo management.

Cinnarizine and dimenhydrinate in the treatment of vertigo in medical practice

The efficacy and safety of the fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg in the treatment of vertigo of various origins have been investigated in a prospective, noninterventional study involving private practices throughout Germany. A total of 1275 patients with an average age of 61.2 years participated in the study. The vertigo symptoms, measured by a validated mean vertigo score (primary efficacy endpoint) improved by 61 % in the course of the observational period (median: 6 weeks). Concomitant symptoms frequently associated with vertigo such as nausea, vomiting and tinnitus were also markedly reduced by 84, 85 and 51 %, respectively. Overall efficacy has been rated by the physicians as 'very much improved' or 'much improved' in 95 % of the patients. A total of 47 patients (3.7 %) reported 51 adverse drug reactions (all nonserious). The results indicate a good tolerability and efficacy of the fixed combination of cinnarizine and dimenhydrinate in the treatment of vertigo in daily medical practice, which is in line with previous findings of numerous interventional, randomised, double-blind, controlled clinical trials.

Fixed combination of cinnarizine and dimenhydrinate in the prophylactic therapy of vestibular migraine: an observational study

Vestibular migraine (VM) is one of the most frequent causes of episodic vertigo, with a lifetime prevalence of 0.98%. Prophylactic therapy includes calcium channel blockers, beta-blockers, antiepileptic drugs and antidepressants. We studied the association of cinnarizine 20 mg and dimenhydrinate 40 mg (Arlevertan) in a group of 22 patients affected by definite VM. Proposed therapy included one tablet twice a day for 1 month, which was repeated three times with 1 month of interval between drug intake; results were compared with those of a control group of 11 VM patients who asked to observe only lifestyle measures for migraine. The main outcome was the number of vertigo and headache crises in the 6 months before therapy and in the 6 months of follow-up. Subjects performing Arlevertan presented during the 6 months of therapy a decrease of vertigo attacks from 5.3 to 2.1 and of headaches from 4.3 to 1.7 (p < 0.0001); 68% of these subjects reported a decrease of at least 50% of vertigo attacks, while 63% of headaches. Conversely, vertigo attacks decreased from 3.5 to 2.2 and headaches from 2.6 to 2 in patients observing only lifestyle; 18% of these subjects reported a decrease of at least 50% of vertigo crises and 27% of headaches. Our data do not differ from those of previous works assessing efficacy of different prophylactic therapies for VM and reporting consistent reduction of vertigo spells in a rate of patients ranging from 60 and 80%.

Comparison of the therapeutic efficacy of a fixed low-dose combination of cinnarizine and dimenhydrinate with betahistine in vestibular neuritis: a randomized, double-blind, non-inferiority study

BACKGROUND

Vestibular neuritis (VN) is a strongly disabling disease of the peripheral vestibular system. Rapid and effective relief of symptoms is important to allow patients to promptly return to normal physical activity.

OBJECTIVE

The aim of this prospective, randomized, double-blind study was to evaluate the efficacy of a fixed low-dose combination of cinnarizine and dimenhydrinate in unilateral VN in comparison with betahistine in terms of improvement of vertigo and concomitant symptoms, and performance in neurotological testing.

METHODS

Sixty-two patients were randomized to receive either cinnarizine 20 mg/dimenhydrinate 40 mg as a fixed combination or betahistine 12 mg, each three times daily for 4 weeks. Vertigo and concomitant symptoms, activities of daily living (ADL), posturography and a battery of vestibulo-ocular tests, registered by electronystagmography including spontaneous nystagmus, bithermal caloric and rotatory test, among others, were assessed at baseline (t(0)), after 1 week (t(1w)) and after 4 weeks (t(4w)). The primary endpoint was the Mean Vertigo Score (MVS) at t(1w), a composite of 12 individual scores for unprovoked and provoked vertigo, each assessed using a 10 cm visual analogue scale (VAS). Non-inferiority of the fixed combination versus betahistine would be assumed if the two-sided 95% confidence intervals (CIs) for between-group differences in MVS lay entirely below the non-inferiority margin of 1.25 (12.5% of VAS range).

RESULTS

The fixed combination led to significantly greater improvements in MVS than betahistine both at t(1w) (primary endpoint) and at t(4w) (95% CI for the difference in baseline-adjusted means -0.95, -0.64 at t(1w), -0.77, -0.44 at t(4w); p < 0.001). Vegetative symptoms and ADL also improved significantly more under the fixed combination than under betahistine at t(1w) (p < 0.001, each parameter) and t(4w) (p < 0.001 and p < 0.01, respectively), both showing a nearly complete remission at t(4w). In the two groups, pathological posturography and electronystagmography parameters normalized during the 4-week treatment. The fixed combination group showed an earlier recovery of spontaneous nystagmus than the betahistine group (t(1w), p < 0.001) and slightly higher improvements in asymmetry of rotation-induced nystagmus at t(1w) and t(4w) (p = 0.041, each time point). No significant differences were found between the treatments in abatement of spontaneous nystagmus at t(4w) and decrease of caloric lateralization or improvement of equilibrium (sensory organization test [SOT], conditions 5/6) at t(1w) and t(4w). No patient reported any adverse event.

CONCLUSION

The results showed that the fixed low-dose combination of cinnarizine and dimenhydrinate is an effective and well tolerated option for symptomatic treatment in unilateral VN. The fixed combination led to significant improvements in vertigo and ADL within the first week, and to a nearly complete recovery after 4 weeks. Neurotological testing revealed no signs of a possible detrimental influence of the 4-week treatment with the fixed combination compared with betahistine in terms of recovery of caloric responsiveness and abatement of rotation-induced nystagmus.

Comparison of cinnarizine/dimenhydrinate fixed combination with the respective monotherapies for vertigo of various origins: a randomized, double-blind, active-controlled, multicentre study

BACKGROUND AND OBJECTIVE

Vertigo may arise from dysfunction in the peripheral and/or the central vestibular system. Simultaneous activity of a medication at both sites will serve to improve the efficacy of antivertigo treatment. The aim of this study was to compare the efficacy and tolerability of a fixed combination of the peripherally acting cinnarizine (20 mg) plus the centrally acting dimenhydrinate (40 mg) with those of equally dosed monotherapies in the treatment of vertigo of various origins.

METHODS

This prospective, randomized, double-blind, active-controlled, multicentre study included patients who assessed at least one vertigo symptom as being of at least medium intensity (≥2) on a 5-point visual analogue scale (VAS; ranging from 0 = not present to 4 = very strong) and who had pathological vestibulospinal movement patterns and/or nystagmus reactions. Patients were randomly assigned to receive either cinnarizine 20 mg/dimenhydrinate 40 mg as a fixed combination, cinnarizine 20 mg as monotherapy or dimenhydrinate 40 mg as monotherapy, each three times daily for 4 weeks. Patients were examined at baseline (t(0)), and after 1 week (t(1w)) and 4 weeks (t(4w)) of treatment. The primary efficacy endpoint was the decrease in mean vertigo score (MVS) at t(4w), which was calculated by averaging the total score for 12 individual vertigo symptoms, each assessed using the 5-point VAS.

RESULTS

The study included 182 patients, of whom 177 were evaluable for efficacy. The mean ± SD reduction in MVS after 4 weeks of treatment with the fixed combination (-1.44 ± 0.56) was significantly greater than the reductions with each of the active treatments alone (cinnarizine -1.04 ± 0.53; dimenhydrinate -1.06 ± 0.56; p = 0.0001, both comparisons). Cinnarizine 20 mg/dimenhydrinate 40 mg as a fixed combination was associated with a significantly higher responder rate (78% of patients with MVS ≤0.5 at t(4w)) than the monotherapies. The odds ratios for MVS ≤0.5 at t(4w) in the cinnarizine or dimenhydrinate groups versus the fixed combination group were 0.345 and 0.214, respectively. The fixed combination reduced concomitant vegetative symptoms significantly more effectively than cinnarizine at both t(1w) (p < 0.05) and t(4w) (p < 0.01). Nine patients reported 15 adverse events (AEs) [three AEs for the fixed combination, six AEs each for cinnarizine and dimenhydrinate]. At t(4w) the tolerability of the treatments was rated as very good or good by almost all patients in all groups (fixed combination and dimenhydrinate 96.6% each; cinnarizine 98.3%).

CONCLUSION

The fixed combination of cinnarizine 20 mg/dimenhydrinate 40 mg was an effective and well tolerated treatment for patients with vestibular vertigo of central and/or peripheral origin. The efficacy of the fixed combination exceeded that of each of the equally dosed active substances given as monotherapy, leading to higher responder rates, and showed a very good and comparable tolerability with a similar or even smaller rate of adverse events than the active substances given alone.

Neuropharmacology of vestibular system disorders

This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Otolaryngologists are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in our knowledge of the fundamental mechanisms of vestibular system function and drug mechanisms of action. In this work, drugs acting on vestibular system have been grouped into two main categories according to their primary mechanisms of action: those with effects on neurotransmitters and neuromodulator receptors and those that act on voltage-gated ion channels. Particular attention is given in this review to drugs that may provide additional insight into the pathophysiology of vestibular diseases. A critical review of the pharmacology and highlights of the major advances are discussed in each case.