Ephedrine for myasthenia gravis, neonatal myasthenia and the congenital myasthenic syndromes

Abstract

Background

Myasthenia is a condition in which neuromuscular transmission is affected by antibodies against neuromuscular junction components (autoimmune myasthenia gravis, MG; and neonatal myasthenia gravis, NMG) or by defects in genes for neuromuscular junction proteins (congenital myasthenic syndromes, CMSs). Clinically, some individuals seem to benefit from treatment with ephedrine, but its effects and adverse effects have not been systematically evaluated.

Objectives

To assess the effects and adverse effects of ephedrine in people with autoimmune MG, transient neonatal MG, and the congenital myasthenic syndromes.

Search methods

On 17 November 2014, we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. We also searched reference lists of articles, conference proceedings of relevant conferences, and prospective trial registers. In addition, we contacted manufacturers and researchers in the field.

Selection criteria

We considered randomised controlled trials (RCTs) and quasi‐RCTs comparing ephedrine as a single or add‐on treatment with any other active treatment, placebo, or no treatment in adults or children with autoimmune MG, NMG, or CMSs.

Data collection and analysis

Two review authors independently assessed study design and quality, and extracted data. We contacted study authors for additional information. We collected information on adverse effects from included articles, and contacted authors.

Main results

We found no RCTs or quasi‐RCTs, and therefore could not establish the effect of ephedrine on MG, NMG and CMSs. We describe the results of 53 non‐randomised studies narratively in the Discussion section, including observations of endurance, muscle strength and quality of life. Effects may differ depending on the type of myasthenia. Thirty‐seven studies were in participants with CMS, five in participants with MG, and in 11 the precise form of myasthenia was unknown. We found no studies for NMG. Reported adverse effects included tachycardia, sleep disturbances, nervousness, and withdrawal symptoms.

Authors' conclusions

There was no evidence available from RCTs or quasi‐RCTs, but some observations from non‐randomised studies are available. There is a need for more evidence from suitable forms of prospective RCTs, such as series of n‐of‐one RCTs, that use appropriate and validated outcome measures.

Plain language summary

Ephedrine treatment for myasthenia gravis, neonatal myasthenia and congenital myasthenic syndromes

Review question

We reviewed the evidence about the effect of ephedrine in adults and children with myasthenia gravis (MG), neonatal myasthenia and the congenital myasthenic syndromes (CMSs).

Background

Myasthenia is a group of rare conditions in which muscle fatigue and weakness are the main symptoms. These symptoms occur because signals do not pass from the nerve to the muscle properly. In autoimmune MG and neonatal myasthenia, the person’s own immune system attacks the proteins that carry these signals. In CMS, there are inborn defects in these proteins. Most people with myasthenia respond well to standard drug and supportive treatments. Ephedrine could have a role when initial treatment is not successful. Ephedrine is a stimulating drug, although exactly how it works is unknown. As far as we know, the use of ephedrine has never been properly assessed in people with myasthenia.

Key results and quality of the evidence

Randomised studies provide the best quality evidence. We did not find any randomised studies of ephedrine in neonatal myasthenia, autoimmune MG, or the CMSs. Fifty‐three non‐randomised studies, which provide weaker evidence than randomised studies, have reported the effects of ephedrine on muscle weakness, fatigue, and quality of life. We have described these findings narratively in the Discussion section of the review. Effects may differ depending on the type of myasthenia. Adverse effects that were reported in these studies included palpitations, sleep disturbances, nervousness, and irritability when ephedrine was stopped. We conclude that there is a need for high‐quality studies to assess the effects of ephedrine in MG, neonatal myasthenia, and the CMSs.

The evidence is current to November 2014.