Formulation and optimization of dimenhydrinate emulgels for topical delivery using response surface methodology.

Development of dimenhydrinate (DMN) emulgel formulation has been described in this work with enhanced permeation for transdermal delivery of DMN for effective management of motion sickness. Various DMN emulgel formulations were prepared using central composite design in response surface methodology. Propylene glycol and olive oil were used in varying ratios as permeation enhancers along-with carbopol-934 as gelling agent. Prepared formulations were evaluated by physico-chemical properties, stability and Fourier transform infrared spectroscopy (FTIR) studies. In-vitro drug release was studied using cellophane membrane. Formulation F2 showed maximum drug permeation following diffusion-based release mechanism and was used in further studies. Rat skin was used in Franz cell for ex-vivo studies to determine various permeation kinetic parameters. FTIR studies provided no evidence of chemical interaction between DMN and polymers used, whereas molecular docking revealed formation of a stable complex in the presence of aqueous environment with stable intermolecular binding and the complex was well hydrated. No evidence of skin irritation was observed in human volunteers following application of the optimized formulation. Histopathology data of the rat skin showed a decreased proliferation of the lymphocytes whereas monocytes were induced. In conclusion, combination of propylene glycol and olive oil was successfully employed for delivery of DMN through transdermal route with good permeability and prolonged release time that can be highly beneficial in treating motion sickness in unusual circumstances.

In vitro evaluation of a self-emulsifying drug delivery system (SEDDS) for nasal administration of dimenhydrinate.

The objective of the study was the development and in vitro characterization of a self-emulsifying drug delivery system (SEDDS) for the nasal application of dimenhydrinate. Final composition of SEDDS was established based on drug solubility and stability studies. Dimenhydrinate was loaded into the SEDDS pre-concentrates to 7.5% (m/v). The droplet size of the final SEDDS formulations was in a range between 60 and 220 nm. Permeability, as well as tissue toxicity, of the formulations was investigated using bovine nasal mucosa. Enhancement in permeation up to 2.8-fold compared to pure dimenhydrinate was confirmed. Furthermore, toxicity studies did not reveal any serious tissue damages related to the SEDDS. Additionally, irritation potential of SEDDS was evaluated in ciliary beat frequency measurements. Incorporation of dimenhydrinate into SEDDS might therefore be considered as a promising approach within the field of nasal delivery of antiemetics by utilizing permeation enhancement strategy.

Psychotropics in Your Medicine Cabinet: A Case Study of Dimenhydrinate Use.

: Reporting of intoxication and withdrawal from aberrant use of over-the-counter medication has been sparse and inconsistent in literature. Attributed to their anticholinergic properties, medications such as dimenhydrinate (Gravol) taken in supratherapeutic doses have been associated with euphoria, anxiolysis, and hallucinations. We present a case of a woman in her forties, with a psychiatric history of bipolar disorder, and complex concurrent medical history including familial Mediterranean fever (FMF), and fibromyalgia, admitted for withdrawal management of her intravenous dimenhydrinate use. As a result of her FMF, there were numerous hospital admissions and treatment which required intravenous access. Hence, a physician-inserted intravenous access port was placed on her chest. The port was maintained monthly with the help of a community agency. In this port, she was injecting 100 to 200 mg of dimenhydrinate hourly for its euphoric and calming effects, consuming upwards of 2400 mg/d. Comprehensive laboratory work-up and urine drug screening were unremarkable. Vital signs were stable. Her mental status at time of admission was lethargic, unfocused, but calm. Her withdrawal symptoms included severe nausea, vomiting, sedation, headaches, dizziness, anxiety, and muscle stiffness. Her detoxification was managed with benztropine and lorazepam, and was well tolerated. The patient was discharged to a community inpatient rehabilitation center. Urine drug testing before discharge was negative. This case draws attention to the addictive potential of dimenhydrinate and offers a regime for its medical withdrawal management. Additionally, this case highlights that screening and management of over-the-counter medications warrants further clinical consideration and investigation.

Diphenhydramine pharmacokinetics after oral and intravenous administration of diphenhydramine and oral administration of dimenhydrinate to healthy dogs, and pharmacodynamic effect on histamine-induced wheal formation: a pilot study.

BACKGROUND: Histamine type-1 (H1) receptor antagonists such as diphenhydramine are frequently used for treatment of pruritus in dogs, yet therapeutic efficacy for allergic disorders is reported to be highly variable. Dimenhydrinate is a salt of diphenhydramine and 8-chlorotheophylline, and has been reported to produce superior oral absorption of diphenhydramine. HYPOTHESIS/OBJECTIVE: To determine the pharmacokinetic and pharmacodynamic properties of diphenhydramine in dogs after intravenous (1 mg/kg) and oral (5 mg/kg) administration, and when given orally as dimenhydrinate at a dose of 10 mg/kg (≈5 mg/kg diphenhydramine). ANIMALS: Each drug was administered to six healthy, fasted mixed-breed dogs in a research facility, using a cross-over design. METHODS AND MATERIALS: Blood samples were collected for pharmacokinetic analysis of diphenhydramine and chlorotheophylline at defined intervals. Pharmacodynamic response was measured by histamine-mediated cutaneous wheal formation. RESULTS: There was great variability in the data and one dog was an extreme outlier. The mean systemic availabilities of diphenhydramine were 7.8% and 22.0% after oral administration of diphenhydramine and dimenhydrinate, respectively, whereas the mean maximum concentrations were 36 (± 20) and 124 (± 46) ng/mL. The terminal elimination half-lives of diphenhydramine and dimenhydrinate were 5.0 (± 7.1) and 11.6 (± 17.7) h, respectively. Plasma diphenhydramine concentrations did not correlate with the percentage reduction in histamine-induced wheal formation. Theophylline reached plasma concentrations considered to be therapeutic for dogs. CONCLUSION: Oral absorption of diphenhydramine was approximately three times greater with a longer half-life when it was administered as the combination product dimenhydrinate.

Intranasally administered in situ gelling nanocomposite system of dimenhydrinate: preparation, characterization and pharmacodynamic applicability in chemotherapy induced emesis model.

The aim of the current manuscript was to test the applicability of a nanocomposite system of penetration enhancer vesicles (PEVs) within polymeric in situ forming gel network composed of poloxamer and hyaluronic acid for the intranasal delivery of the antiemetic dimenhydrinate (DMH). PEVs were prepared using phospholipids and labrasol/transcutol/PEG 400 as penetration enhancers, and characterized for entrapment efficiency (EE%), particle size, zeta potential and morphology. The nanocomposite in situ forming gel system was characterized for its sol-gel temperature, viscosity and mucoadhesiveness, and was pharmacodynamically tested on a cisplatin induced emesis model in rats in terms of food, water, kaolin intake and stomach weight content. The selected PEVs formula displayed EE% of 83% for DMH, particle size of 121 nm and a surface charge of 0.83 mV. The selected nanocomposite in situ gelling formula showed a viscosity of 2.13 Pa.S, mucoadhesive force of 0.62 N and DMH controlled release over 6 hours. The pharmacodynamic study showed the superiority of the nanocomposite in situ gelling formula; being administered at a lower dose than the oral marketed formula. The described nanocomposite system proved to be successful for the intranasal delivery of DMH, thus presenting a promising delivery modality for similar antiemetics.

Comparison of Dexamethasone-Dimenhydrinate and Dexamethasone-Ondansetron in Prevention of Nausea and Vomiting in Postoperative Patients.

INTRODUCTION: Postoperative Nausea and Vomiting is one of the most common problems after implementation of general anesthesia. The incidence can reach 80% in high-risk patients, depending on the type of surgery. In our study, we aimed to compare dexamethasone-dimenhydrinate and dexamethasone-ondansetron combinations in prevention of nausea and vomiting in postoperative patients. METHOD: Sixty 18-65-year-olds ASAI-II females who underwent rhinoplasty were included in the study. Patients were randomly included in two groups: Dexamethasone-dimenhydrinate group (group DD) and dexamethasone-ondansetron group (group DO). All patients received dexamethasone 8 mg iv after endotracheal intubation. Anesthesia continuation was established with sevoflurane, air-oxygen mixture and remifentanil infusion. At the 30th minute of the operation, group DO received ondansetron 4 mg iv and group DD received dimenhydrinate 1 mg/kg iv. For postoperative analgesia tramadol (1.5 mg/kg) iv, tenoksikam (20 mg) and afterward for postoperative patient-controlled tramadol was used. In the postoperative recovery room, nausea and vomiting were evaluated at the 30th, 60th, 120th minutes and at the end of 24 h. Total amount of tramadol was recorded. All results were statistically evaluated. OBSERVATIONS: Demographics and Apfel risk scores of both groups were similar. Surgical operation duration (p = 0.038) and total preoperative remifentanil consumption were higher in group DD (p = 0.006). In group DO, nausea at 30 and 60 min (p = 0.001, p = 0.007), retching at 30 and 60 min (p = 0.002, p = 0.006) were higher than group DD. The additional antiemetic need in group DO was significantly higher at 30 min (p = 0.001). Postoperative analgesic consumption was similar in both groups. RESULT: Our study revealed that dexamethasone-dimenhydrinate combination was more effective than dexamethasone-ondansetron in prevention of nausea and vomiting after rhinoplasty operations. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Preparation and in-vivo evaluation of dimenhydrinate buccal mucoadhesive films with enhanced bioavailability.

Dimenhydrinate (DMH)-loaded buccal bioadhesive films for the prevention and treatment of motion sickness were prepared and optimized. This study examines the rate of drug release from the films for prolonged periods of time to reduce or limit the frequency of DMH administration. Based on preliminary studies using various polymers and concentrations, hydroxyethylcellulose (2.5, 3.0, and 3.2%), and xanthan gum (2.8%) were chosen as matrix polymers. The films were analyzed with respect to their mechanical, physicochemical, bioadhesive, swelling, and in-vitro release properties. In in-vivo pharmacokinetic studies, xanthan gum-based DMH buccal film was associated with significantly increased DMH plasma levels between 1 h and 5 h after DMH dosing when compared with an oral drug solution. The area under the curve AUC0-7 h value of the mucoadhesive buccal film was two-fold higher than the oral DMH solution. Histological analysis revealed that DMH films cause mild morphological and inflammatory changes in rabbit buccal mucosa. The DMH buccal film is effective for approximately 7 h, thus representing an option for single-dose antiemetic therapy. This dosage regimen could be particularly beneficial for chain travelers who travel for long periods of time.

Comparison of the therapeutic efficacy of intravenous dimenhydrinate and intravenous piracetam in patients with vertigo: a randomised clinical trial.

BACKGROUND: The present study aimed to compare the therapeutic efficacy of dimenhydrinate and piracetam in patients with vertigo. METHODS: A blinded, parallel group, superiority, randomised clinical trial was carried out on patients who presented to the emergency department (ED) with vertigo. Healthy adult patients presenting to the ED with undifferentiated vertigo were included in the study. The efficacy of intravenous dimenhydrinate (100 mg) and intravenous piracetam (2000 mg) for reducing the intensity of vertigo was compared in two randomised treatment groups using a 10-point numeric rating scale (NRS). The determination of NRS scores was performed at presentation and at the 30th minute of presentation, after the study drug was implemented, both in immobile and ambulatory positions. The primary outcome variable was reduction in vertigo intensity documented on the NRS at the 30th minute after medication administration, analysed by intention to treat. RESULTS: A total of 94 patients were included in the randomisation (n=47 in both groups). The baseline NRS scores were 7.55±2.00 in the dimenhydrinate group and 8.19±1.79 in the piracetam group. The changes from baseline for dimenhydrinate and piracetam were 2.92±3.11 and 3.75±3.40 (difference -0.83 (95% CI -2.23 to 0.57)) in the immobile position and were 2.04±3.07 and 2.72±2.91 (difference -0.68 (95% CI -2.03 to 0.67)) in the ambulatory position. Rescue medication need was similar in both treatment groups (p=0.330), and only one adverse reaction was reported. CONCLUSIONS: We found no evidence of a difference between dimenhydrinate and piracetam in relieving the symptoms of vertigo. TRIAL REGISTRATION NUMBER: Clinical Trials Registration ID: NCT01890538.

Prediction of oral absorption of cinnarizine--a highly supersaturating poorly soluble weak base with borderline permeability.

Two important driving forces for oral absorption of active pharmaceutical ingredients are drug dissolution and permeability in the gastrointestinal tract. Poorly soluble weak bases typically exhibit high solubility under fasted gastric conditions. However, the solubility of such drugs usually decreases drastically in the fasted small intestine, constraining drug absorption. Since there is a discrepancy in solubility between the fasted state stomach and intestine, it is crucial to examine the influence of dissolution, supersaturation and precipitation on the oral absorption of poorly soluble weak bases during and after fasted state gastric emptying. Cinnarizine is a poorly soluble weak base with borderline permeability, exhibiting supersaturation and precipitation under simulated fasted state gastric emptying conditions. Interestingly, supersaturation and precipitation of cinnarizine under fed state conditions is not expected to occur, since the drug shows good solubility in fed state biorelevant media and exhibits a positive food effect in pharmacokinetic studies. The present work is aimed at investigating the dissolution, supersaturation and precipitation behavior of marketed cinnarizine tablets under fasted and fed state conditions using biorelevant dissolution and transfer methods. In order to predict the in vivo performance of these cinnarizine formulations, the in vitro results were then coupled with different physiologically based pharmacokinetic (PBPK) models, which considered either only dissolution or a combination of dissolution, supersaturation and precipitation kinetics. The results of the in silico predictions were then compared with in vivo observations. The study revealed that under fasting conditions, plasma profiles could be accurately predicted only when supersaturation and precipitation as well as dissolution were taken into account. It was concluded that for poorly soluble weak bases with moderate permeability, supersaturation and precipitation during fasted state gastric emptying may have an essential influence on oral drug absorption and thus on in vivo drug performance.

Vestibular suppressants after canalith repositioning in benign paroxysmal positional vertigo.

OBJECTIVES/HYPOTHESIS: To investigate the characteristics of residual symptoms and to evaluate the effects of adjuvant vestibular suppressants on residual symptoms after successful canalith repositioning procedures (CRPs). STUDY DESIGN: Individual randomized controlled trial. METHODS: One hundred fifty patients with idiopathic benign paroxysmal positional vertigo who achieved successful CRPs on initial visit participated in this study. Dizziness Handicap Inventory (DHI) questionnaires were completed before CRPs. All study populations were divided into three groups after successful CRPs on the initial visit day: the medication (V) group (treated with a vestibular suppressant [dimenhydrinate 50 mg per day]), the placebo (P) group, and the no medication (N) group. One week after successful CRPs, residual symptoms were checked and repeated DHI questionnaires were completed to compare residual symptoms. RESULTS: Among the 138 patients who did not show positional nystagmus at follow-up, 67 (48.5%) complained of residual symptoms. The presence of residual symptoms was more prevalent in the P and N group compared with the V group (P = .035, P = .017, respectively). The most frequent residual symptom was lightheadedness (n = 42). Moreover, in the V group, lightheadedness was significantly reduced compared with the P group (P = .029). However, in the analysis of DHI, total and subscale scores did not differ across the three groups before or after successful CRP. CONCLUSIONS: Vestibular suppressants significantly reduced residual symptoms compared to both placebo and no medication after CRP. However, there was no significant reduction in DHI score compared with the control group, suggesting that the residual symptoms could not be evaluated by DHI score alone.

Comparison of the effectiveness of intravenous piracetam and intravenous dimenhydrinate in the treatment of acute peripheral vertigo in the emergency department.

INTRODUCTION: We aimed to compare the effectiveness of intravenous piracetam with that of intravenous dimenhydrinate in the treatment of acute peripheral vertigo in the emergency department. METHODS: This double-blind study comprised a total of 200 patients, aged between 18 and 70 years, who had presented to the emergency department of Ankara Training and Research Hospital and were diagnosed with peripheral vertigo. Evaluation of the severity of the patients' vertigo was performed using a visual analogue scale, before and after drug administration. RESULTS: Both drugs were found to be effective (p < 0.001) and had comparable effects (p < 0.474). Dimenhydrinate was also found to have about two times the side effects of piracetam. Drowsiness was found to be the most common side effect of these two drugs. CONCLUSION: Dimenhydrinate and piracetam have similar levels of effectiveness with regard to acute vertigo. We conclude that piracetam, which has fewer side effects than dimenhydrinate, better vestibular compensation, and is effective for both acute and chronic vertigo, could be more frequently used in the emergency treatment of acute vertigo.

[How safe are dimenhydrinate suppositories?]. / Wie sicher sind Dimenhydrinat-Suppositorien?

HISTORY: A 13-month-old girl suffered from 3 generalized tonic-clonic seizures for several minutes within a total period of 9 hours. History revealed that the child received a total of 5 dimenhydrinate containing suppositories à 40 mg during the previous 2 days (i. e. 23 mg dimenhydrinate per kg body weight) due to enteritis with vomiting. The first seizure occurred 10 hours after the last administration. INVESTIGATIONS: The plasma level of diphenhydramin was 230 µg/l approximately one hour after the first seizure. Electroencephalography showed no pathological signs, an MRI scan of the brain was normal except of several small gliotic spots and body temperature was regularly. TREATMENT AND COURSE: Two stationary occurring seizures were stopped with 5 mg diazepam rectally. Continued surveillance and an EEG two days later showed age-appropriate normal findings. There were no further seizures in the next 4 years. CONCLUSION: Infants have the risk to develop dimenhydrinate intoxication, especially in cases where suppositories were given repeatedly because of intermittent defecation.

The adjuvant use of lansoprazole, clonazepam and dimenhydrinate for treating intractable hiccups in a patient with gastritis and reflux esophagitis complicated with myocardial infarction: a case report.

BACKGROUND: Hiccup (Singultus) is a sudden and involuntary contraction of the diaphragm followed by a sharp closure of the epiglottis which results in the production of a specific "hic" sound. Normally, hiccups are treated without intervention. Intractable hiccups occur rarely but are a disturbing symptom underlying other health related disorders. CASE PRESENTATION: We report the clinical case of a 67-year-old male patient with myocardial infarction accompanied by intractable hiccups during the course of 8 months, and who was non-responsive to chlorpromazine or metoclopramide, and baclofen; drugs routinely used to treat this condition. This sustained hiccup had severely restricted the patient's ability to intake food and sleep. To explore alternative treatments, we investigated the adjuvant administration of lansoprazole, dimenhydrinate and clonazepam in this patient. We discovered that this drug combination was capable of successfully terminating his intractable hiccups, with no further evidence of recurrence. No similar treatment is previously reported for intractable hiccups. We further suggest a hypothesis concerning a potential mechanism on the anti-hiccup effect of dimenhydrinate. CONCLUSION: We identified that the adjuvant use of lansoprazole, clonazepam and dimenhydrinate was capable of attenuating the symptoms of our patient with intractable hiccups.

Nausea and vomiting in pregnancy: a review of the pathology and compounding opportunities.

Nausea and vomiting in pregnancy can have serious adverse effects on the quality of a woman's life, affecting her occupational, social, and domestic functioning, and her general well-being; therefore, it is very important to treat this condition appropriately and effectively. Evidence-based algorithms support the use of oral pyridoxine alone or combined with doxylamine as first-line treatment. Promethazine or dimenhydrinate, known as a second-line treatment, should be added to the first-line treatment or should be added only to pyridoxine according to different algorithms. In most of the world, there is a lack of approved medicines using this combination approach known as the first-line treatment. Therefore, compounding pharmacists should supply the demand by compounding 10-mg pyridoxine hydrochloride and 10-mg doxylamine succinate slow-release capsules. Since transdermal promethazine does not exist world wide, and, since this medicine has significant added values compared to the oral/rectal dosage forms, compounding pharmacists should offer physicians transdermal promethazine as a second-line therapy in nausea and vomiting in pregnancy. This review summarizes the nausea and vomiting in pregnancy problems and discusses the compounding opportunities that exist in this common and wide-spread pathology in order to improve a woman's quality of life.

Oral dimenhydrinate versus placebo in children with gastroenteritis: a randomized controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of oral dimenhydrinate in the treatment of acute gastroenteritis. METHODS: This was a randomized, double-blind, placebo-controlled trial conducted in the emergency department of a pediatric university-affiliated center. Children 1 to 12 years old who presented to the emergency department with at least 5 episodes of vomiting in the previous 12 hours and diagnosed with acute gastroenteritis were block-randomized to receive oral dimenhydrinate (1 mg/kg; maximum: 50 mg) every 6 hours for 4 doses or placebo for 4 doses. The primary outcome measure was treatment failure as defined by the occurrence of ≥ 2 episodes of vomiting in the 24 hours after administration of the first dose of the study medication. RESULTS: During the study period, 209 patients met inclusion criteria, but 50 refused to participate and 7 were missed. Eight participants were lost to follow-up, and 144 were thus included in the primary analysis. Of these patients, 74 were randomized to receive dimenhydrinate and 70 placebo. The proportions of patients showing failure of treatment were similar for both treatment groups: dimenhydrinate, 31% (23 of 74); placebo, 29% (20 of 70) (difference: 0.02 [95% confidence interval: -0.12 to 0.17]). There were no differences between the 2 groups in rates of intravenous cathether insertion, mean number of episodes of vomiting or diarrhea, abdominal pain, nausea, duration of symptoms, revisit rates, or parental absenteeism. The proportions of adverse effects were similar in both groups (53% vs 54%). CONCLUSIONS: The prescription of oral dimenhydrinate did not significantly decrease the frequency of vomiting in children with acute gastroenteritis compared with placebo.

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.