Dimenhydrinate (marketed as Gravol in Canada and Dramamine in the United Kingdom and the United States) is an over-the-counter (OTC) antihistamine indicated for the prevention and relief of nausea and vomiting from a number of causes. It is an H1 receptor antagonist that demonstrates anticholinergic activity. Abuse of dimenhydrinate has been reported, and often involves ingestion of high doses to induce psychotropic effects, including hallucinations and euphoria. Psychiatric patients may also abuse dimenhydrinate to achieve an anti-anxiety effect. In addition to frank abuse, OTC medications, including dimenhydrinate, may be misused when taken in higher doses or for a longer duration than indicated on the product monograph. Potential for drug dependence is also a concern in situations of dimenhydrinate abuse or misuse. Given these potential risks, some jurisdictions have chosen to store and sell dimenhydrinate under pharmacist supervision;5 however, it is available without any restrictions in other jurisdictions. The purpose of this report is to identify the recent clinical evidence on the potential misuse or abuse of dimenhydrinate, in order to inform decision making regarding appropriate access to this drug within the pharmacy.
Disclaimer: The Rapid Response Service is an information service for those involved in planning and providing health care in Canada. Rapid responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. Rapid responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report.
