Dimethyl fumarate is a disease modifying therapy for relapsing remitting MS. Studies have shown that it can reduce the number of relapses by approximately 50%, but many people reported having side effects such as flushing and gastrointestinal (GI) upset such as nausea, vomiting, abdominal pain or diarrhoea. Although these tend to occur in the first few weeks of treatment they can be troublesome. This study surveyed the researchers that had been part of the clinical trials team investigating dimethyl fumarate and asked them for their experience and opinions on how best to deal with these side effects.
In the researchers' experience the side effects could usually be managed using several lifestyle or medication changes. They made recommendations of ways to reduce the impact and severity of flushing and GI upset including:
- taking dimethyl fumarate with food
- temporarily reducing the dose, returning to the full dose within four weeks
- taking aspirin before the dimethyl fumarate dose to reduce flushing
- using loperamide to manage diarrhoea
The researchers recommended that in the future, health professionals should clearly explain the potential for side effects and how they can be managed, to any person with MS starting treatment with dimethyl fumarate; to ensure that they are prepared and aware of what may occur in the first few weeks of treatment.
Dimethyl fumarate is a disease modifying therapy for relapsing remitting MS that was approved for use on the NHS in 2014. Clinical studies have shown that dimethyl fumarate reduces the number of relapses by approximately 50% and MRI scans showed most people had fewer, smaller or no new areas of active MS. However in the clinical trials 36% of people taking dimethyl fumarate reported experiencing flushing and 42% reported gastrointestinal (GI) upset such as nausea, vomiting, abdominal pain or diarrhoea. These side effects tend to occur in the first month or so of treatment before easing off, however they can be troublesome to deal with and it is known that experiencing these symptoms can affect how many people stay using treatment. If side effects such flushing or GI upset can be effectively managed then it is likely more people will continue dimethyl fumarate treatment and benefit from its disease modifying effects.
This study surveyed researchers that had been part of the clinical trials team investigating dimethyl fumarate. The aim of the study was to collect additional information on the characteristics of the flushing and GI upset side effects and find out how the researchers had dealt with them when they occurred. Of 270 researchers that had taken part in the original dimethyl fumarate trials, 84 had looked after at least 10 people with MS during the trials. A questionnaire was sent to these 84 researchers and 30 researchers, all neurologists, completed the survey.
The questionnaire collected information on:
- how often they saw a trial participant with one of the side effects
- how often these side effects occurred
- how bothersome they were
- how long they lasted
- how they managed such side effects
- and asked them what they would do now for people experiencing these side effects based on the experience they gained during the clinical trials.
A number of recommendations for managing flushing and GI upset were formulated based on the opinions and experience of the researchers involved.
Overall the researchers who participated in the study confirmed that these side effects are common in people with MS taking dimethyl fumarate although they tended to decrease with time and could be successfully managed using several lifestyle or medication changes.
The suggested strategies to reduce the impact and severity of flushing and GI upset included:
- taking dimethyl fumarate with food
- temporarily reducing the dose, returning to full dose within four weeks
- taking aspirin before the dimethyl fumarate dose to reduce flushing
- using loperamide to manage diarrhoea
- using metoclopramide or domperidone to manage very severe nausea or vomiting
- using H2-receptor antagonists and proton pump inhibitors to help reduce abdominal pain.
The researchers recommended that in future health professionals should clearly explain the potential for side effects and how they can be managed to any person with MS starting treatment with dimethyl fumarate. To ensure that they are prepared and aware what may occur in the first few weeks of treatment.
Although the researchers made several recommendations based on their own experience only aspirin has so far been evaluated in trials as something that can help reduce dimethyl fumarate side effects. It is also important to remember that these recommendations are based on the researchers' observations and how severe they considered the side effects to be. If the people involved were questioned they may have provided a different answer on their experience of these side effects and they may have additional suggestions to make about how they managed some of these side effects themselves.
Phillips JT, Hutchinson M, Fox R, et al.
Managing flushing and gastrointestinal events associated with delayed-release dimethyl fumarate: experiences of an international panel.
Mult Scler Relat Disord. 2014 Jul;3(4):513-9. [PubMed]
Abstract
Read the full text of this paper
Side effects are unwanted symptoms caused by a medical treatment and can happen with any drug, even something as everyday as aspirin can cause side effects in some people.
Some effects can pass by and be barely noticed and others can be more serious and make a noticeable difference to your wellbeing or ability to go about your day normally. No one wants to take a drug that they think will make them feel better and find that it can actually make them feel worse. For most people the side effects of dimethyl fumarate treatment are relatively mild and manageable, and probably just a bit of an irritation or inconvenience, although for some people they can be more intrusive and cannot be tolerated.
Due to the way that dimethyl fumarate affects the body, flushing and gastrointestinal upset symptoms are common. Although as this study suggests there are a number of lifestyle and treatment modifications you could try to reduce the effect of these.
- When you first start taking dimethyl fumarate you may be advised to start on a lower dose and build this up over the first month to help your body get used to drug and reduce the risk of side effects occurring.
- Studies have shown that taking aspirin before each dose can prevent or reduce flushing.
- Taking doses on a full stomach helps to reduce gastrointestinal upset, although experience suggests this needs to be a balanced meal rather than a light snack.
If you are experiencing side effects that you are finding particularly difficult to deal with, discuss this with your health professionals. There may be an alternative drug or dose that may be better for you.
You can read more about of dimethyl fumarate and the other disease modifying therapies in the A to Z of MS or in our free publication Disease modifying drugs which can be ordered from our shop.
