Salbutamol is a medication most commonly prescribed to treat asthma, and is sometimes referred to as ‘Albuterol’ or ‘Ventolin’.
It works by stimulating a certain part of a cell called a receptor, found within several organs of the body. These receptors are called ‘adrenergic’ and there are several different types. Salbutamol works by stimulating one type of these receptors found in, amongst other places, the lungs. Because these receptors are found in the heart and the muscles, some side effects are reported, including an increase in heart rate.
As well as stimulating receptors, there have been studies that suggest salbutamol may increase the strength of muscles involved in movement in healthy adults1. In SMA, any beneficial effects may be due to the body being encouraged to produce more SMN protein2.
How can you take salbutamol?
When treating asthma, salbutamol is usually breathed in, via an inhaler, to go directly to the lungs. Salbutamol is normally given in tablet or liquid form when treating conditions other than asthma.
Are there any risks in taking salbutamol?
As with any medication, there are potential side effects. The main concern with salbutamol treatment is that there is a small risk of problems with the rhythm of the heart. The heart may beat incorrectly, or too fast. For this reason, a heart check and ECG is often performed before starting on this medication and when receiving it.
What clinical trials have been done?
In 2002 Kinali and colleagues looked at salbutamol in the treatment of SMA with a small number of participants to decide whether it was worth doing a larger study3. The investigators gave doses of salbutamol to 13 individuals with SMA Types 2 or 3. They followed up the participants over a six-month period and found some improvements in breathing and measures of muscle strength. Other studies have looked at individuals with SMA Type 2. Following treatment with salbutamol, the individuals also seemed to show improvements in breathing tests and assessments of movement ability4,5. Morandi and colleagues looked, in total, at 45 patients with SMA Type 3 over one year. 17 of these participants received salbutamol, and there was a significant improvement in the distance the majority of participants could walk (if they could already walk). Overall, the majority of treated participants also improved in other physiotherapy assessments6.
The bottom line:
Some studies of relatively small numbers of patients have found salbutamol to be helpful in improving some of the symptoms caused by SMA.
You can read more about Tiziano and colleagues' study which looked at individuals with SMA Type 3 taking salbutamol over a one year period, here.
Addenbrooke's Hospital have written a leaflet on salbutamol and its use in neuromuscular conditions which you can read here.