People with a wide variety of illnesses can experience symptoms of vertigo. Researchers at University College London in the UK published a new Cochrane Review of the relevant evidence for one possible treatment, betahistine, in June 2016. We asked James Handscome to speak with the lead author Louisa Murdin about the review and its findings.
John: Hello, I'm John Hilton, editor of the Cochrane Editorial unit. People with a wide variety of illnesses can experience symptoms of vertigo. Researchers at University College London in the UK published a new Cochrane Review of the relevant evidence for one possible treatment, betahistine, in June 2016. We asked NAME to speak with the lead author Louisa Murdin about the review and its findings.
James: Hello Louisa, thanks for talking with us about your Cochrane Review. Could you begin by telling us a little about what the review is about?
Louisa: It’s about treatment for vertigo, where individuals experience a false sense of movement or rotation, often caused by inner ear disease. This is a common symptom of many quite different health conditions, but whatever the cause it can be an extremely distressing experience with a big impact on daily life. We wanted to find out whether betahistine is effective for relief of vertigo of any cause related to the inner ear or its nerve connections.
James: So, was the main reason for doing the review the fact that vertigo is common and deeply unpleasant for patients?
Louisa: That was part of the reason. As a clinician treating patients, I often hear about the impact vertigo has on them. I also knew that betahistine is a common treatment in many countries round the world, and I wanted to find out whether there was any benefit from this.
But actually, the main drive for the review came out of a previous Cochrane Review – on betahistine for a condition called Meniere’s disease. Meniere’s disease is one of the conditions where people experience vertigo and although the authors of that review concluded that there was no good evidence for or against the drug for that condition, as their paper was going through the editorial process it was suggested that a review of all patients with vertigo, instead of only those with definite Meniere’s disease, might find a beneficial effect. So that’s what we decided to do. The review was also advocated by a patient organisation, the Meniere’s Society, who had identified this as a question that patients really wanted answered properly.
James: It sounds like a particularly important question for a review, so how did you go about getting the answer?
Louisa: We looked at all the randomised trials for patients with vertigo where betahistine was compared with a sham drug treatment or placebo. The main outcome we investigated was whether patients thought, overall, that being on the drug benefitted them more than the sham treatment.
James: And what did you find?
Louisa: We found 17 trials, with just over a thousand participants, using betahistine for up to 3 months; but we faced a lot of challenges in trying to get a reliable answer from these. One was that a lot of the papers are quite old and the way clinical trials are done and reported has changed so much in the last 10 years, that we had a lot of variability to deal with in both the methods and the results, and it wasn’t possible to get hold of original data for most of the studies.
Eventually, we got to the answer that the proportion of patients reporting a reduction of their vertigo symptoms was significantly higher in the betahistine group than in the placebo group. We also found that the rates of unwanted effects were the same in the two groups, suggesting that there aren't lot of unwanted effects due to the drug.
But (and this is an important “but”) the large amount of variability among the studies means we have to treat our findings with caution, and also the quality of the studies is low, meaning the calculations could be inaccurate.
James: So what now? Do we need a big clinical trial to settle this question once and for all?
Louisa: Well, I guess in an ideal world a big clinical trial would be a great thing to have. But actually our review suggests that the effect is probably quite small, and that the drug is pretty safe. So, in pragmatic terms, I think that a big trial may not turn out to have a high priority claim on scarce resources, especially because it would have to be really large to get a clear answer.
James: So what would be your advice to patients with vertigo and the doctors treating them?
Louisa: The key thing is that it’s really important for patients to get a proper diagnosis for their vertigo as there are so many specific conditions that cause vertigo that have specific effective treatments. However, betahistine may be a reasonable choice to try in the shorter term while the diagnosis is worked out.
John: If you would like to read more about Louisa’s findings, search Cochrane Library dot com for ‘betahistine’, to find her review and the earlier one she mentioned about the use of this drug for Meniere’s disease.