Comparison of Seven Commonly Used Agents for Prophylaxis of Seasickness

Antihistamines for motion sickness

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Trials; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials.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.

Orally consumed ginger and human health: an umbrella review

BACKGROUND

Emerging evidence supports the health benefits of ginger for a range of conditions and symptoms; however, there is a lack of synthesis of literature to determine which health indications are supported by quality evidence.

OBJECTIVES

In this umbrella review of systematic reviews we aimed to determine the therapeutic effects and safety of any type of ginger from the Zingiber family administered in oral form compared with any comparator or baseline measures on any health and well-being outcome in humans.

METHODS

Five databases were searched from inception to April 2021. Review selection and quality were assessed in duplicate using the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) checklist and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method, with results presented in narrative form.

RESULTS

Twenty-four systematic reviews were included with 3% overlap of primary studies. The strongest evidence was found for the antiemetic effects of ginger in pregnant women (effect size: large; GRADE: high), analgesic effects for osteoarthritis (effect size: small; GRADE: high), and glycemic control (effect size: none to very large; GRADE: very low to moderate). Ginger also had a statistically significant positive effect on blood pressure, weight management, dysmenorrhea, postoperative nausea, and chemotherapy-induced vomiting (effect size: moderate to large; GRADE: low to moderate) as well as blood lipid profile (effect size: small; GRADE: very low) and anti-inflammatory and antioxidant biomarkers (effect size: unclear; GRADE: very low to moderate). There was substantial heterogeneity and poor reporting of interventions; however, dosage of 0.5-3 g/d in capsule form administered for up to 3 mo was consistently reported as effective.

CONCLUSIONS

Dietary consumption of ginger appears safe and may exert beneficial effects on human health and well-being, with greatest confidence in antiemetic effects in pregnant women, analgesic effects in osteoarthritis, and glycemic control. Future randomized controlled and dose-dependent trials with adequate sample sizes and standardized ginger products are warranted to better inform and standardize routine clinical prescription.

Clinical Evaluation of the Use of Ginger Extract in the Preventive Management of Motion Sickness

Background

Motion sickness can be triggered in a variety of situations and is characterized primarily by nausea and vomiting. Ginger is widely used in treating conditions including chemotherapy-associated gastrointestinal symptoms, morning sickness, postoperative nausea, and motion sickness.

Objectives

The primary study objective was to evaluate Zingiber officinale extract in the treatment of motion sickness. Secondary objectives were to evaluate treatment effect on Motion Sickness Assessment Questionnaire (MSAQ) score and subscores before and after treatment, and to evaluate treatment tolerability.

Methods

Open-label, single-arm study assessing motion sickness outcomes with and without pre-travel oral treatment with Zingiber officinale 160 mg extract (containing 8 mg gingerols). All patients answered the MSAQ on 4 separate occasions following a trip of at least 15 minutes in duration: Trip 1 (pretreatment) and Trips 2, 3, and 4 (after oral treatment with study medication). The primary end point was percentage of patients presenting improvement ≥20 score points on the MSAQ during Trip 2, Trip 3, and Trip 4 in comparison to pretreatment score (Trip 1). Secondary end points included percentage of patients presenting improvement in MSAQ subscores during Trips 2, 3, and 4; percentage of patients presenting treatment-related adverse events; and pre- and posttreatment physician assessment scores.

Results

One hundred eighty-four patients were included and 174 completed treatment. A reduction of ≥20 points in total MSAQ score points occurred in 26.52%, 29.89%, and 29.31% of patients from Trips 2, 3, and 4, respectively. There was no significant difference at Trips 2, 3, and 4 in number of patients presenting improvement ≥20 score points (P = 0.9579). There was a significant reduction in total MSAQ scores from Trips 2, 3, and 4 (P < 0.0001) compared with Trip 1. Total MSAQ scores did not vary at each trip taken under treatment (P = 0.28). There were significant (P < .001) improvements in all domain subscores from Trips 2, 3, and 4 in relation to scores from Trip 1. There was a significant improvement in physician assessment scores at Visit 2 (P < .0001). Adverse events were reported among 31 patients, mainly affecting the gastrointestinal system. Twenty-four patients (13.04%) reported 39 adverse events considered related to treatment. No significant change in physical exam was noted at Visit 2 in relation to Visit 1.

Conclusions

These open label, historically controlled study results suggest the need for randomized, blinded, placebo and active substance controlled clinical trials. (Curr Ther Res Clin Exp. 2020; 81:XXX–XXX)

Does the Oral Administration of Ginger Reduce Chemotherapy-Induced Nausea and Vomiting?: A Meta-analysis of 10 Randomized Controlled Trials

BACKGROUND

Preclinical tests in animals have shown that ginger extract can be used to treat chemotherapy-induced nausea and vomiting (CINV); however, research findings in clinical trials have not been conclusive.

OBJECTIVE

Through this meta-analysis, we aimed to determine whether ginger could be used to treat CINV, which was interpreted using the PICOS (patient, problem/population, intervention, comparison, outcome, study) framework, with P being patients who underwent chemotherapy; I being 0.5 to 2.0 g/d of Zingiberaceae, Zintoma, dry ginger, ginger capsules, powdered ginger root, Zingiber officinale Roscoe, ginger extract, powdered ginger, 6-gingerol, or shogalos; C being placebo or standard care; and O being the relief, reduction, or improvement of CINV.

METHOD

Via systematic literature review, we searched for studies in English from 2000 to 2017 in databases. We conducted a meta-analysis using Comprehensive Meta-analysis 2 on a total of 10 studies with complete data.

RESULTS

The odds ratio (OR) of ginger in controlling CINV was 0.71 (95% confidence interval [CI], 0.54-0.94; P = .015). Heterogeneity existed among the samples; therefore, we proceeded with a subgroup analysis and divided nausea and vomiting into acute or delayed. The results revealed that ginger could only reduce acute CINV in patients (OR, 0.60; 95% CI, 0.42-0.86; P = .006), particularly acute vomiting (OR, 0.58; 95% CI, 0.37-0.94; P = .025).

CONCLUSIONS

Ginger displayed significant efficacy with regard to controlling CINV in the experimental groups.

IMPLICATIONS FOR PRACTICE

Our results could provide a reference for antiemetic methods to treat CINV and facilitate support for more clinical trials in the future to establish relevant guidelines.

Ginger-Mechanism of action in chemotherapy-induced nausea and vomiting: A review

Despite advances in antiemetic therapy, chemotherapy-induced nausea and vomiting (CINV) still poses a significant burden to patients undergoing chemotherapy. Nausea, in particular, is still highly prevalent in this population. Ginger has been traditionally used as a folk remedy for gastrointestinal complaints and has been suggested as a viable adjuvant treatment for nausea and vomiting in the cancer context. Substantial research has revealed ginger to possess properties that could exert multiple beneficial effects on chemotherapy patients who experience nausea and vomiting. Bioactive compounds within the rhizome of ginger, particularly the gingerol and shogaol class of compounds, interact with several pathways that are directly implicated in CINV in addition to pathways that could play secondary roles by exacerbating symptoms. These properties include 5-HT3, substance P, and acetylcholine receptor antagonism; antiinflammatory properties; and modulation of cellular redox signaling, vasopressin release, gastrointestinal motility, and gastric emptying rate. This review outlines these proposed mechanisms by discussing the results of clinical, in vitro, and animal studies both within the chemotherapy context and in other relevant fields. The evidence presented in this review indicates that ginger possesses multiple properties that could be beneficial in reducing CINV.

Ginger for Prevention of Antituberculosis-induced Gastrointestinal Adverse Reactions Including Hepatotoxicity: A Randomized Pilot Clinical Trial

In this study, the potential benefits of ginger in preventing antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity have been evaluated in patients with tuberculosis. Patients in the ginger and placebo groups (30 patients in each group) received either 500 mg ginger (Zintoma)(®) or placebo one-half hour before each daily dose of antituberculosis drugs for 4 weeks. Patients' gastrointestinal complaints (nausea, vomiting, dyspepsia, and abdominal pain) and antituberculosis drug-induced hepatotoxicity were recorded during the study period. In this cohort, nausea was the most common antituberculosis drug-induced gastrointestinal adverse reactions. Forty eight (80%) patients experienced nausea. Nausea was more common in the placebo than the ginger group [27 (90%) vs 21 (70%), respectively, p = 0.05]. During the study period, 16 (26.7%) patients experienced antituberculosis drug-induced hepatotoxicity. Patients in the ginger group experienced less, but not statistically significant, antituberculosis drug-induced hepatotoxicity than the placebo group (16.7% vs 36.7%, respectively, p = 0.07). In conclusion, ginger may be a potential option for prevention of antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity. Copyright © 2016 John Wiley & Sons, Ltd.

Ginger hexane extract suppresses RANKL-induced osteoclast differentiation

Osteoporosis is a debilitating disease caused by decreased bone density. Compounds with anti-osteoclastic activity, such as bisphosphonates, may help in the prevention and treatment of osteoporosis. Herein, we determined the inhibitory effects of ginger hexane extract (GHE) on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells. The results showed that GHE (1) suppressed osteoclast differentiation and the formation of actin rings; (2) inhibited the expression of Nfatc1, a master transcriptional factor for osteoclast differentiation, in a dose-dependent manner (10-20 μg/mL); and (3) inhibited other osteoclastogenesis-related genes, such as Oscar, Dc-stamp, Trap, and Mmp9. These findings suggest that GHE may be used to prevent and treat osteoporosis by inhibiting osteoclast differentiation.

A comparison of cinnarizine and transdermal scopolamine for the prevention of seasickness in naval crew: a double-blind, randomized, crossover study

OBJECTIVES

The objective of the study was to compare the efficacy of transdermal scopolamine and cinnarizine in the prevention of seasickness and their adverse reactions.

METHODS

Seventy-six naval crew members participated in a double-blind, randomized, crossover study. On 2 voyages, they were administered either a transdermal scopolamine patch containing 1.5 mg scopolamine and placebo tablets or 25-mg cinnarizine tablets and a placebo patch. Subjects completed questionnaires for each voyage, reporting on the efficacy of the drugs, the severity of their adverse reactions, and the preferred treatment.

RESULTS

Subjects reported the scopolamine patch to be significantly more effective than the cinnarizine tablet (P = 0.029). A moderate to high degree of drowsiness was attributed more frequently to cinnarizine than to the scopolamine patch (34% and 17%, respectively; P < 0.02). Any adverse reaction, to at least a moderate degree, was more frequent with cinnarizine (38%) than with the scopolamine patch (22%), although the significance of this association was borderline. A significantly greater percentage of subjects preferred transdermal scopolamine to cinnarizine (41 vs 12%, P < 0.001).

CONCLUSIONS

Higher efficacy, a lower rate of adverse reactions, and convenience all led the participants of this study to prefer the scopolamine patch to cinnarizine. Considering the 2 therapeutic options assessed in this study, and in light of the findings of previous studies, it is recommended that the scopolamine patch be used as the drug of choice for the treatment of seasickness among naval crew in particular and probably also among all other sea travelers.

The ups and downs of motion sickness

OVERVIEW

Nearly everyone will experience motion sickness at some point. It's thought to be caused by confusion among the vestibular, visual, and proprioceptive systems; the associated nausea is thought to involve neurons in the hypothalamus and a portion of the cerebral cortex. Although many remedies are available, none has been proven to be effective for everyone. Pharma cologic treatments include antihistamines, scopolamine, and gingerroot. Nonpharmacologic treatments include efforts to control gastric motility, such as wearing a wristband that stimulates the P6 acupressure point, and efforts to affect the vestibular, visual, and proprioceptive systems, such as facing forward, riding at the front of a boat, and looking toward the horizon, among others. Nurses can help patients find the remedy that works best for them.

Current treatment of nausea and vomiting associated with gastroparesis: antiemetics, prokinetics, tricyclics

Gastroparesis is a symptomatic chronic disorder characterized by delayed gastric emptying without a mechanical obstruction. Gastroparesis is most often associated with diabetes, gastric surgery, and systemic disorders affecting the neuromuscular control of the stomach. However, no underlying etiology can be found in up to 40% of patients, a condition referred to as idiopathic gastroparesis. Due to the numerous potential etiologies and the highly variable clinical manifestations, the management of gastroparesis is particularly challenging. The purpose of this review is to provide an update on the use of antiemetics, prokinetics, and tricyclics for the treatment for nausea and vomiting associated with gastroparesis.

A novel animal model for motion sickness and its first application in rodents

The present work was designed to establish a novel animal model for motion sickness (MS) in rodents and to evaluate the effects of a combination of scopolamine and modafinil on MS with this novel method. It was found that the rats and mice presented several symptoms induced by rotation such as, piloerection, tremble, urinal and fecal incontinence. As the rats and mice are lack of emesis response to rotation, we used a score based on abovementioned symptoms as an index for the severity of MS in rodents. MS index was determined in 260 mice with this novel method. It was found that the distribution of MS index was normal (W=0.99; P=0.23. P>0.05 considered values' normal distribution). The effects of scopolamine on MS were studied in mice and rats. It was found that scopolamine significantly decreased MS index at the dose of 0.3 mg/kg in mice and 1.0 mg/kg in rats. Finally, the effects of a combination of scopolamine and modafinil were observed with this novel method in rats. It was found that the efficacy of the combination (5.0+5.0 mg/kg) was greater than the single drugs (10 mg/kg). Even the smallest dose of the combination (0.5+0.5 mg/kg) had a similar effect to large dose of scopolamine or modafinile when they were used alone. In conclusion, this animal model is suitable for MS study in rats and mice and the combination of scopolamine and modafinil might be a new method to treat or prevent MS.

Transdermal scopolamine for prevention of motion sickness : clinical pharmacokinetics and therapeutic applications

A transdermal therapeutic system for scopolamine (TTS-S) was developed to counter the adverse effects and short duration of action that has restricted the usefulness of scopolamine when administered orally or parenterally. The plaster contains a reservoir of 1.5 mg of scopolamine programmed to deliver 0.5 mg over a 3-day period. A priming dose (140 microg) is incorporated into the adhesive layer to saturate certain binding sites within the skin and to accelerate the achievement of steady-state blood levels. The remainder is released at a constant rate of approximately 5 microg/hour. The protective plasma concentration of scopolamine is estimated to be 50 pg/mL. TTS-S attains that concentration after 6 hours; a steady state of about 100 pg/mL is achieved 8-12 hours after application. Yet 20-30% of subjects failed to attain the estimated protective concentration, and plasma concentrations measured in subjects who failed to respond to TTS-S were lower than in responders. These findings may explain some of the treatment failures. Overall, the product appears to be the approximate functional equivalent of a 72-hour slow intravenous infusion. A combination of transdermal and oral scopolamine (0.3 or 0.6 mg) was effective and well tolerated in producing desired plasma concentrations 1-hour post-treatment. TTS-S has proved to be significantly superior to placebo in reducing the incidence and severity of motion sickness by 60-80%. It was more effective than oral meclizine or cinnarizine, similar to oral scopolamine 0.6 mg or promethazine plus ephedrine, and the same as or superior to dimenhydrinate. The addition of ephedrine or the use of two patches did not improve its efficacy, but rather increased the rate of adverse effects. TTS-S was most effective against motion sickness 8-12 hours after application. Despite previous evidence to the contrary, a recent bioavailability study demonstrated similar intraindividual absorption and sustained clinical efficacy with long-term use of the drug. The adverse effects produced by TTS-S, although less frequent, are qualitatively typical of those reported for the oral and parenteral formulations of this agent. Dry mouth occurs in about 50-60% of subjects, drowsiness in up to 20%, and allergic contact dermatitis in 10%. Transient impairment of ocular accommodation has also been observed, in some cases possibly the result of finger-to-eye contamination. Low-dose pyridostigmine was found effective in preventing cycloplegia but not mydriasis. Adverse CNS effects, including toxic psychosis (mainly in elderly and paediatric patients), have been reported only occasionally, as have difficulty in urinating, headache, rashes and erythema. Adverse effects were not correlated with plasma scopolamine concentrations. TTS-S produced only about half the incidence of drowsiness caused by oral dimenhydrinate or cinnarizine, and a level of adverse effects similar to that found with oral meclizine. Performance is not affected by short-term use. Prolonged or repeated application may cause some impairment of memory storage for new information. However, sea studies revealed significantly less reports of a decrement in performance or drowsiness due to prevention of sea sickness. The recommended dosage is a single TTS-S patch applied to the postauricular area at least 6-8 hours before the anti-motion sickness effect is required. For faster protection, the patch may be applied 1 hour before the journey in combination with oral scopolamine (0.3 or 0.6 mg). After 72 hours, the patch should be removed and a new one applied behind the opposite ear. Its place in therapy is mainly on long journeys (6-12 hours or longer), to avoid repeated oral doses, or when oral therapy is ineffective or intolerable.

Zingiberis rhizoma: a comprehensive review on the ginger effect and efficacy profiles

Zingiberis rhizoma is used as a broadspectrum antiemetic. We, therefore, conducted a comprehensive review of the literature to summarize the pharmacological and clinical effects of this popular plant material. Although clinical and experimental studies suggest that ginger has some antiemetic properties, clinical evidence beyond doubt is only available for pregnancy-related nausea and vomiting. Meta-analyses could not demonstrate the postoperative antiemetic effectiveness, and effect in motion sickness or nausea/vomiting of other ethiology. It also remains to be confirmed that proprietary ginger preparations are clinically useful to alleviate osteoarthritic or other pain, although there is no doubt that ginger constituents interfere with the inflammatory cascade and the vanilloid nociceptor. Ginger exerts in vitro antioxidative, antitumorigenic and immunomodulatory effects and is an effective antimicrobial and antiviral agent. Animal studies demonstrate effects on the gastrointestinal tract, the cardiovascular system, on experimental pain and fever, antioxidative, antilipidemic and antitumor effects, as well as central and other effects. The most relevant human pharmacological studies require a confirmatory study to exclude interaction of ginger preparations with platelet aggregation. Pharmacokinetic data are only available for [6]-gingerol and zingiberene. Preclinical safety data do not rule out potential toxicity, which should be monitored especially following ginger consumption over longer periods.

Effectiveness and safety of ginger in the treatment of pregnancy-induced nausea and vomiting

OBJECTIVE

Conventional antiemetics are burdened with the potential of teratogenic effects during the critical embryogenic period of pregnancy. Thus, a safe and effective medication would be a welcome addition to the therapeutic repertoire. This systematic review was aimed at assessing the evidence for or against the efficacy and safety of ginger (Zingiber officinale) therapy for nausea and vomiting during pregnancy.

DATA SOURCES

Systematic literature searches were conducted in 3 computerized databases (MEDLINE, EMBASE, and Cochrane Library), and the reference lists of all papers located were checked for further relevant publications.

METHODS OF STUDY SELECTION

For the evaluation of efficacy, only double-blind, randomized controlled trials (RCTs) were included. All retrieved clinical data, including uncontrolled trials, case reports, observational studies, and RCTs, were included in the review of safety.

TABULATION, INTEGRATION, AND RESULTS

Six double-blind RCTs with a total of 675 participants and a prospective observational cohort study (n = 187) met all inclusion criteria. The methodological quality of 4 of 5 RCTs was high. Four of the 6 RCTs (n = 246) showed superiority of ginger over placebo; the other 2 RCTs (n = 429) indicated that ginger was as effective as the reference drug (vitamin B6) in relieving the severity of nausea and vomiting episodes. The observational study retrieved and RCTs (including follow-up periods) showed the absence of significant side effects or adverse effects on pregnancy outcomes. There were no spontaneous or case reports of adverse events during ginger treatment in pregnancy.

CONCLUSION

Ginger may be an effective treatment for nausea and vomiting in pregnancy. However, more observational studies, with a larger sample size, are needed to confirm the encouraging preliminary data on ginger safety.

LEVEL OF EVIDENCE

I.

[Is ginger a clinically relevant antiemetic? A systematic review of randomized controlled trials]

BACKGROUND AND OBJECTIVE

The aim of this systematic review was to evaluate the clinical impact of ginger (Zingiber officinale) as an antiemetic.

METHODS

A systematic search of the literature was performed using the databases of MEDLINE, EMBASE, and the Cochrane-Library.

RESULTS

Of 100 published reports discerned as potentially relevant, 24 randomized controlled trials were evaluated, covering 1073 patients which had received ginger. Of these reports, 16 contained information regarding the antiemetic activity of the phytotherapeutic agent against kinetosis, postoperative nausea and vomiting (PONV), and morning sickness and hyperemesis gravidarum, respectively. Only a few studies were eligible for a quantitative analysis (meta-analysis). Thus, the majority of the reports were analyzed descriptively. To analyze the potential side effects of the drug, 15 reports with 777 patients were eligible. Of these, 3.3% suffered from slight side effects, mainly mild gastrointestinal symptoms and sleepiness, both not requiring specific treatments. One severe adverse event was reported in a study: an abortion occurred in the 12th week of gestation. However, a total of 136 patients were treated with ginger within the first trimenon of pregnancy without complications.

CONCLUSION

There is no clear evidence for the efficacy of ginger in the treatment of PONV and of kinetosis. The results for the treatment of nausea and vomiting in pregnancy are encouraging, however, ginger should be applied for the time being only in controlled clinical studies. Applied in daily doses up to 6 g ginger seems to be a drug with few side effects.

The contribution of expectations to motion sickness symptoms and gastric activity

OBJECTIVE

The goal of this investigation was to determine in healthy adults the effect of expectation manipulations on the development of motion sickness, as indicated by abnormal gastric myoelectric activity and subjective reports of symptoms of motion sickness.

METHOD

Eighty participants, moderately susceptible to motion sickness, experienced one of four conditions created from a two-variable (Expectation, Drum), two-factor model (High/Low expectation for sickness; Rotating/Stable Drum). The electrogastrogram (EGG) was recorded 6 min prior to the expectation manipulation; 6 min following the expectation manipulation; 6 min before drum activation; and 16 min during drum activation. Self-report questionnaires indicating expectation for sickness (MSEx) and motion sickness symptoms (Nausea Profile [NP]) were obtained following the expectation manipulation and exposure to the drum, respectively.

RESULTS

No significant differences were observed among expectation groups for retrospective reports of motion sickness (NP); however, significant differences in EGG responses to drum rotation were obtained. The unexpected results of a univariate analysis of variance (ANOVA) revealed significantly greater gastric tachyarrhythmia and less normal activity, an indication of motion sickness, in the low expectation for sickness conditions.

CONCLUSION

These results suggest that inducing a high expectation for sickness in healthy individuals about to be exposed to provocative motion results in a protective effect from motion sickness following exposure to the stimulus, while low expectations may induce abnormal gastric activity.

Prevention of common travel ailments

An understanding of the subjects covered in this article is significant in keeping travelers healthy and comfortable. Each section covers a range of problems and suggestions for their prevention. The areas that are reviewed are: 1) fitness to fly; 2) problems in transit; 3) altitude sickness; 4) marine and swimming hazards; 5) insect precautions; 6) pre- and posttravel care; and 7) illness abroad. An effort has been made to provide practical recommendations as in many cases there is little data and no rules, thus the travel health advisor, with the patients' input, will need to determine the best course of action for each individual and itinerary.

A week in the life of a travel clinic

International travel has increased enormously in recent years. With the greater movement of people have come increased encounters with a wide variety of diseases: malaria, dengue, cholera, typhoid fever, Ebola virus, and many more. The need for greater scope, consistency, and knowledgeability in pretravel health care to meet these challenges has been met by the emergence of the discipline of travel medicine. Travelers are well advised to become informed of the risks they face and to take steps to minimize those risks. After reviewing a traveler's medical history and a detailed itinerary, a travel medicine practitioner can offer expert advice on behavioral modifications, immunizations, and chemoprophylaxis regimens which will increase the traveler's margin of safety. The issues most frequently addressed in a travel clinic include treatment of traveler's diarrhea, malaria chemoprophylaxis, and immunizations, for hepatitis A, typhoid fever, tetanus/diphtheria, influenza, pneumococcus, hepatitis B, polio, meningococcus, measles, mumps, rubella, varicella, and rabies. Pretravel consultation must consider the age and underlying health problems of the traveler, the nature of the trip (wilderness, jungle, rural, urban, resort, or cruise), the duration of travel, and the latest available information on the site in terms of disease outbreaks, terrorism, and natural calamities.