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Pharmacology, Biochemistry, and Behavior Apr 2003Dimenhydrinate (DMH; trade names Gravol and Dramamine) is a compound of diphenhydramine (DP) and 8-chlorotheophylline in equimolar ratios. DMH has been reported to be...
Dimenhydrinate (DMH; trade names Gravol and Dramamine) is a compound of diphenhydramine (DP) and 8-chlorotheophylline in equimolar ratios. DMH has been reported to be abused by humans for its euphoric and hallucinogenic properties but few studies have evaluated its reinforcing effects in animals. To evaluate the hypothesis that DMH and its constituents DP and 8-chlorotheophylline are rewarding in animals, rats were tested for conditioned place preference (CPP). The paradigm consisted of pre-exposure (three 15-min sessions of access to both sides of the chamber), conditioning [eight 30-min pairings of one side with drug (four sessions) and, on alternate days, the other side with vehicle (four sessions)] and test phases (three 15-min sessions of access to both sides of the chamber). Significant preferences for the drug-paired location were found on test session one after conditioning with 60.0, but not 25.0, 40.0 or 50.0 mg/kg of DMH, and after conditioning with 37.8 but not 27.0 or 32.4 mg/kg of DP. No preference was found after conditioning with 23.0, 27.6 or 32.2 mg/kg of 8-chlorotheophylline. All three drugs stimulated locomotor activity during conditioning sessions and DMH and DP showed sensitization over conditioning sessions. DMH doses that showed sensitization (25.0 and 40.0 mg/kg) were lower than the dose (60.0 mg/kg) that produced a CPP revealing a dissociation of locomotor stimulating versus rewarding effects. Results reveal that DMH and DP have rewarding properties, although the molar equivalent dose-response curve for DP appeared to be further to the right than that for DMH. Future investigations into the neurotransmitter systems modulating this effect are awaited.
Topics: Animals; Conditioning, Operant; Dimenhydrinate; Diphenhydramine; Dose-Response Relationship, Drug; Histamine H1 Antagonists; Male; Motor Activity; Rats; Rats, Wistar; Theophylline
PubMed: 12759125
DOI: 10.1016/s0091-3057(03)00068-6 -
International Journal of Environmental... Apr 2021Vertigo 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...
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.
Topics: Adult; Cinnarizine; Dimenhydrinate; Double-Blind Method; Drug Combinations; Female; Histamine H1 Antagonists; Humans; Male; Middle Aged; Vertigo
PubMed: 33946152
DOI: 10.3390/ijerph18094787 -
Perceptual and Motor Skills Jun 1997
Clinical Trial
Topics: Adolescent; Adult; Alpha Rhythm; Cerebral Cortex; Dimenhydrinate; Electroencephalography; Female; Fourier Analysis; Histamine H1 Antagonists; Humans; Male; Signal Processing, Computer-Assisted
PubMed: 9172229
DOI: 10.2466/pms.1997.84.3.1105 -
European Journal of Anaesthesiology May 1999Dimenhydrinate is an inexpensive antihistaminic drug, that is frequently used as an anti-emetic during anaesthesia. The popularity of the drug is contrasted by the lack... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Dimenhydrinate is an inexpensive antihistaminic drug, that is frequently used as an anti-emetic during anaesthesia. The popularity of the drug is contrasted by the lack of modern studies concerning its efficacy in reducing the incidence of post-operative nausea and vomiting. Thus, dimenhydrinate was compared with placebo in this prospective, randomized, double-blind study. One hundred and thirty-three female in-patients were studied. They were stratified according to the type of surgery (laparoscopic cholecystectomy, thyroid resection or knee arthroscopy) to ensure an homogeneous distribution in both groups. General anaesthesia was induced with etomidate, fentanyl, vecuronium and maintained with enflurane in N2O/O2. Neuromuscular block was reversed with pyridostigmine/atropine. Patients in the dimenhydrinate group (n = 67) received 62 mg dimenhydrinate intravenously after induction of anaesthesia. Placebo patients (n = 66) received saline. Administration of dimenhydrinate (and placebo) was repeated three times during the 48-h study to mitigate the short half-life of the drug. Post-operative analgesia and anti-emetic rescue medication was standardized. Episodes of vomiting, retching and the need for additional anti-emetics were recorded. Nausea was assessed using a 10-cm visual analogue scale. Post-operative nausea and vomiting was rated as 'none', 'mild', 'moderate' and 'severe' using a fixed scoring algorithm. There were no differences between the two groups with regard to biometric data, type of surgery and distribution of risk factors for developing post-operative nausea and vomiting. In the dimenhydrinate group, more patients remained completely free from post-operative nausea and vomiting compared with placebo (dimenhydrinate: 38.8%; placebo: 15.1%; P = 0.004). The incidence of severe post-operative nausea and vomiting was also reduced from 39.4% to 14.9%. No relevant side effects were observed. Intra-operative dimenhydrinate, followed by three further administrations after surgery, reduces the incidence and the severity of post-operative nausea and vomiting without side effects. However, there still remained an unacceptable high number of patients who were not prevented completely from experiencing post-operative nausea and vomiting.
Topics: Adult; Antiemetics; Arthroscopy; Cholecystectomy, Laparoscopic; Dimenhydrinate; Double-Blind Method; Female; Humans; Knee Joint; Middle Aged; Postoperative Nausea and Vomiting; Prospective Studies; Thyroidectomy
PubMed: 10390662
DOI: 10.1046/j.1365-2346.1999.00477.x -
Progress in Neuro-psychopharmacology &... Jan 2008To investigate the effects of dimenhydrinate on cerebral oxygen status (COS; cerebral oxygenated hemoglobin concentration changes) and salivary chromogranin-A (CgA)... (Randomized Controlled Trial)
Randomized Controlled Trial
To investigate the effects of dimenhydrinate on cerebral oxygen status (COS; cerebral oxygenated hemoglobin concentration changes) and salivary chromogranin-A (CgA) during a cognitive test battery, a double-blind, placebo-controlled, randomized, crossover protocol was used to examine the effect of 50 mg of dimenhydrinate or placebo in 12 subjects. This test battery includes tests of both reaction time and fundamental cognitive ability and was used in the assessment of pilots. Poor cognitive performance was observed in the subjects taking dimenhydrinate. We used two-channel near-infrared spectroscopy to investigate the effects of dimenhydrinate on the COS. With the one exception of shifting attention task in the left forehead, no significant difference was found between dimenhydrinate and placebo during the tasks of the test battery. Under placebo treatment, on the other hand, CgA levels were significantly elevated during cognitive testing when compared with baseline. However, CgA levels were not significantly elevated above baseline following dimenhydrinate. The present study is one of the first to demonstrate that the first-generation antihistamine drugs altered the responses of salivary CgA during cognitive tasks. The changes in salivary CgA secretion, as a result of dimenhydrinate administration, may serve as a sensitive biomarker of a psychological status such as a drug-induced sedation during the performance of a cognitive test battery. Further studies, however, are required to examine the usefulness of this sensitive biomarker in investigation of psychological agents during cognitive tasks.
Topics: Adult; Analysis of Variance; Cerebral Cortex; Chromogranin A; Cognition; Cross-Over Studies; Dimenhydrinate; Double-Blind Method; Female; Hemoglobins; Histamine H1 Antagonists; Humans; Male; Middle Aged; Neuropsychological Tests; Saliva; Spectroscopy, Near-Infrared; Time Factors
PubMed: 17765381
DOI: 10.1016/j.pnpbp.2007.07.018 -
The Cochrane Database of Systematic... Oct 2022Motion sickness is a syndrome that occurs as a result of passive body movement in response to actual motion, or the illusion of motion when exposed to virtual and moving... (Review)
Review
BACKGROUND
Motion sickness is a syndrome that occurs as a result of passive body movement in response to actual motion, or the illusion of motion when exposed to virtual and moving visual environments. The most common symptoms are nausea and vomiting. Antihistamines have been used in the management of motion sickness for decades, however studies have shown conflicting results regarding their efficacy.
OBJECTIVES
To assess the effectiveness of antihistamines in the prevention and treatment of motion sickness in adults and children.
SEARCH METHODS
The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 7 December 2021.
SELECTION CRITERIA
Randomised controlled trials (RCTs) in susceptible adults and children in whom motion sickness was induced under natural conditions such as air, sea and land transportation. We also included studies in which motion sickness was induced under experimental conditions (analysed separately). Antihistamines were included regardless of class, route or dosage and compared to no treatment, placebo or any other pharmacological or non-pharmacological interventions.
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods. Our primary outcomes were 1) the proportion of susceptible participants who did not experience any motion sickness symptoms; 2) the proportion of susceptible participants who experienced a reduction or resolution of existing symptoms. Secondary outcomes were 1) physiological measures (heart rate, core temperature and gastric tachyarrhythmia (electrogastrography)) and 2) adverse effects (sedation, impaired cognition, blurred vision). We used GRADE to assess the certainty of the evidence for each outcome.
MAIN RESULTS
We included nine RCTs (658 participants). Studies were conducted across seven countries, with an overall age range of 16 to 55 years. Motion sickness was induced naturally in six studies and experimentally in four studies (rotating chair). All the naturally induced studies only evaluated first-generation antihistamines (cinnarizine and dimenhydrinate). Risk of bias across the studies varied, with mostly low risk for random sequence generation and allocation concealment, and mostly high risk for selective reporting. Only the experimentally induced studies measured physiological parameters and only the naturally induced studies evaluated adverse effects. There were no studies that clearly assessed the paediatric population. Antihistamines versus placebo or no treatment Antihistamines are probably more effective than placebo at preventing motion sickness symptoms under natural conditions (symptoms prevented: 25% placebo; 40% antihistamines) (risk ratio (RR) 1.81, 95% confidence interval (CI) 1.23 to 2.66; 3 studies; 240 participants) (moderate-certainty). The evidence is very uncertain about the effect of antihistamines on preventing motion sickness under experimental conditions (standardised mean difference (SMD) 0.32, 95% CI -0.18 to 0.83; 2 studies; 62 participants) (very low-certainty). No studies reported results on the resolution of existing motion sickness symptoms. Antihistamines may result in little or no difference in gastric tachyarrhythmia under experimental conditions (mean difference (MD) -2.2, 95% CI -11.71 to 7.31; 1 study; 42 participants) (low-certainty). No studies reported results for any other physiological measures. When compared to placebo, antihistamines may be more likely to cause sedation (sedation: 44% placebo; 66% antihistamines) (RR 1.51, 95% CI 1.12 to 2.02; 2 studies; 190 participants) (low-certainty); they may result in little or no difference in blurred vision (blurred vision: 12.5% placebo; 14% antihistamines) (RR 1.14, 95% CI 0.53 to 2.48; 2 studies; 190 participants) (low-certainty); and they may result in little or no difference in terms of impaired cognition (impaired cognition: 33% placebo; 29% antihistamines) (RR 0.89, 95% CI 0.58 to 1.38; 2 studies; 190 participants) (low-certainty). Antihistamines versus scopolamine The evidence is very uncertain about the effect of antihistamines on preventing motion sickness under natural conditions when compared to scopolamine (symptoms prevented: 81% scopolamine; 71% antihistamines) (RR 0.89, 95% CI 0.68 to 1.16; 2 studies; 71 participants) (very low-certainty). No studies were performed under experimental conditions. No studies reported results on the resolution of existing motion sickness symptoms. The evidence is very uncertain about the effect of antihistamines on heart rate under natural conditions (narrative report, 1 study; 20 participants; "No difference in pulse frequency"; very low-certainty). No studies reported results for any other physiological measures. When compared to scopolamine, the evidence is very uncertain about the effect of antihistamines on sedation (sedation: 21% scopolamine; 30% antihistamines) (RR 0.82, 95% CI 0.07 to 9.25; 2 studies; 90 participants) (very low-certainty) and on blurred vision (narrative report: not a significant difference; 1 study; 51 participants; very low-certainty). No studies evaluated impaired cognition. Antihistamines versus antiemetics Antihistamines may result in little or no difference in the prevention of motion sickness under experimental conditions (MD -0.20, 95% CI -10.91 to 10.51; 1 study; 42 participants) (low-certainty). The evidence is of low certainty due to imprecision as the sample size is small and the confidence interval crosses the line of no effect. No studies assessed the effects of antihistamines versus antiemetics under natural conditions. No studies reported results on the resolution of existing motion sickness symptoms. Antihistamines may result in little or no difference in gastric tachyarrhythmia (MD 4.56, 95% CI -3.49 to 12.61; 1 study; 42 participants) (low-certainty). No studies reported results for any other physiological measures. No studies evaluated sedation, impaired cognition or blurred vision. One study reported physiological data for this outcome, evaluating gastric tachyarrhythmia specifically. Antihistamines may result in little or no difference in gastric tachyarrhythmia (MD 4.56, 95% CI -3.49 to 12.61; 1 study; 42 participants; low-certainty evidence). This evidence is of low certainty due to imprecision as the sample size is small and the confidence interval crosses the line of no effect. Antihistamines versus acupuncture The evidence is very uncertain about the effects of antihistamines on the prevention of motion sickness under experimental conditions when compared to acupuncture (RR 1.32, 95% CI 1.12 to 1.57; 1 study; 100 participants) (very low-certainty). This study did not assess the prevention of motion sickness under natural conditions, nor the resolution of existing motion sickness symptoms. There was no study performed under natural conditions. Physiological measures and adverse effects were not reported.
AUTHORS' CONCLUSIONS
There is probably a reduction in the risk of developing motion sickness symptoms under naturally occurring conditions of motion when using first-generation antihistamines, in motion sickness-susceptible adults, compared to placebo. Antihistamines may be more likely to cause sedation when compared to placebo. No studies evaluated the treatment of existing motion sickness, and there are few data on the effect of antihistamines in children. The evidence for all other outcomes and comparisons (versus scopolamine, antiemetics and acupuncture) was of low or very low certainty and we are therefore uncertain about these effects of antihistamines.
Topics: Adolescent; Adult; Antiemetics; Child; Cinnarizine; Dimenhydrinate; Histamine Antagonists; Humans; Middle Aged; Motion Sickness; Scopolamine Derivatives; Young Adult
PubMed: 36250781
DOI: 10.1002/14651858.CD012715.pub2 -
The American Journal of Psychiatry Feb 1972
Topics: Adult; Dimenhydrinate; Hallucinations; Humans; Male; Psychoses, Substance-Induced; Substance-Related Disorders
PubMed: 5058102
DOI: 10.1176/ajp.128.8.1012 -
Pediatrics Jun 2012To evaluate the efficacy and safety of oral dimenhydrinate in the treatment of acute gastroenteritis. (Randomized Controlled Trial)
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.
Topics: Administration, Oral; Antiemetics; Child; Child, Preschool; Dimenhydrinate; Double-Blind Method; Female; Follow-Up Studies; Gastroenteritis; Headache; Humans; Infant; Male; Sleep Stages; Treatment Outcome; Vomiting
PubMed: 22585774
DOI: 10.1542/peds.2011-2945 -
Acta Anaesthesiologica Scandinavica Mar 2002Diphenhydramine and its theoclate salt dimenhydrinate are traditional antiemetics still in use. However, so far the quantitative effect of dimenhydrinate in the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Diphenhydramine and its theoclate salt dimenhydrinate are traditional antiemetics still in use. However, so far the quantitative effect of dimenhydrinate in the prophylaxis of postoperative nausea and vomiting (PONV) has not been evaluated systematically.
METHODS
Results from randomized controlled trials investigating the efficacy of dimenhydrinate vs. a control to prevent PONV were included in a meta-analysis. Studies were systematically searched through MEDLINE, EMBASE, the Cochrane-Library, manually screening of reference lists of matching review articles and current issues of locally available peer-reviewed anesthesia journals, up to June 2001. The numbers of patients with complete absence of PONV within 6 h and within 48 h after surgery were extracted as the main end point. Pooled relative benefits (RB) and numbers-needed-to-treat (NNT) with their corresponding 95% confidence intervals (CI) were calculated using a random effects model. This quantitative systematic review was performed following the recommendations of the QUORUM statement. In all, 18 trials with 3045 patients were included in the analysis: 1658 patients received a placebo (control) and 1387 patients received dimenhydrinate.
RESULTS
The RB to stay completely free of PONV was 1.2 (95% CI: 1.1-1.4) for the early period (NNT = 8; 95% CI: 5-25) and 1.5 (1.3-1.8) for the overall investigated period (NNT = 5; 95% CI: 3-9).
CONCLUSION
Dimenhydrinate is a traditional and inexpensive antiemetic with an efficacy that might be considered as clinically relevant. Although in use for a long time, the dose-response, precise estimation of side-effects, optimal time of administration and the benefit of repetitive doses still remain unclear.
Topics: Adult; Antiemetics; Child; Dimenhydrinate; Humans; Postoperative Nausea and Vomiting; Randomized Controlled Trials as Topic
PubMed: 11939912
DOI: 10.1034/j.1399-6576.2002.t01-1-460303.x -
Acute Inhibition of the Human Kv1.5 Channel by H Receptor Antagonist Dimenhydrinate: Mode of Action.Biological & Pharmaceutical Bulletin 2023Dimenhydrinate, an H receptor antagonist, is generally used for the prevention and treatment of nausea and vomiting. However, cardiac arrhythmias have been reported to...
Dimenhydrinate, an H receptor antagonist, is generally used for the prevention and treatment of nausea and vomiting. However, cardiac arrhythmias have been reported to be associated with the overdose of histamine H receptor antagonists, indicating the probable effect of antihistamines on ion channels. By using a two-microelectrode voltage clamp, we have herein studied the electrophysiological effects of dimenhydrinate on the human Kv1.5 channel in the Xenopus oocyte expression system. Dimenhydrinate acutely and reversibly suppressed the amplitudes of the peak and the steady-state current, within 6 min. The inhibitory effect of dimenhydrinate on the peak and the steady-state Kv1.5 currents increased progressively from -10 to +50 mV. At each test voltage, the drug suppressed both the peak and the steady-state currents to a similar extent. When the oocytes were stimulated at the rates of 5- and 30-s intervals, dimenhydrinate-induced a use-dependent blockade of the human Kv1.5 channel. Dimenhydrinate expedited the timecourse of the Kv1.5 channel activation more effectively than the timecourse of its inactivation. However, the activation and inactivation curves of the channel were not altered by the H receptor antagonist. In conclusion, we found that dimenhydrinate inhibits the human Kv1.5 channel by changing the channel's activation mode, thereby possibly increasing the possibility of triggering cardiac arrhythmias and affecting atrial fibrillation.
Topics: Humans; Dimenhydrinate; Electrophysiological Phenomena; Histamine H1 Antagonists; Oocytes; Potassium Channel Blockers
PubMed: 37779040
DOI: 10.1248/bpb.b23-00170