What is Symbicort SMART?
In most countries outside of the United States, there is an approved dosing strategy for the combination inhaler Symbicort known as Symbicort SMART. Why SMART is not currently approved in the United States is an answer I do not have, but it is approved in “most countries”. 1 Symbicort, like other combination inhalers Dulera (Zenhale) and Advair, as well as other formulations available outside of North America such as Fostair and Flutiform, works by treating both components of asthma and constriction of airways by use of a long-acting beta-2 agonist (LABA), also known as a “long-acting bronchodilator”, and inflammation of airways by way of an inhaled corticosteroid (ICS).
Under SMART, patients take the prescribed number of inhalations of Symbicort twice daily (about 12 hours apart), as well as use 1 puff of the same inhaler as their rescue medication. The uniqueness of Symbicort SMART therapy is because of the LABA component, fluticasone.
The rationale of Symbicort SMART
SMART stands for Symbicort Maintenance and Reliever Therapy—so, kind of like the "ATM machine" being the automated teller machine, it’s technically Symbicort Symbicort Maintenance and Reliever Therapy. 😉 As I mentioned, the drug formoterol is why SMART works.
Formoterol is a LABA with rapid onset, within 1-3 minutes of taking a dose. Comparatively, salmeterol (in Advair) takes 15-30 minutes to take effect—which is why salmeterol should never be used as a rescue medication, it simply does not work fast enough. Conversely, formoterol acts rapidly enough to relieve acute bronchospasm—the constriction that occurs in an asthma exacerbation. So, it makes sense that formoterol be approved for use for acute asthma symptoms, just like salbutamol/albuterol is.
Why the inhaled steroid?
The rationale for a combined ICS/LABA as a rescue medication is, simply, that both constriction and inflammation components of asthma need to be treated. If there is an increase in constriction, theoretically there is also an increase in the inflammation in the lungs, so pairing a dose of bronchodilator with the anti-inflammatory component of an ICS is said to prevent exacerbations from becoming worse by responding rapidly with an inhaled steroid. As well, research indicates that there is a recursive effect whereby ICS and LABA make one another more effective. 2 Simply: SMART is an effective rescue treatment for asthma by way of a rapid-acting bronchodilator and may offer a way to curb inflammation leading to increased symptoms with the combined dosage of ICS—and, in tandem, the drugs may work together more effectively.
Is SMART more effective than separate inhalers?
There was no difference in time before asthma exacerbation between those using SMART and those on traditional therapy, and no difference in how well patients tolerated SMART vs traditional asthma management. 3 Early studies of SMART (2009) indicated lower ICS dosing overall in those using SMART, as well as lower cost. 3As well, fewer asthma exacerbations occurred in the group using SMART, giving validity to the hope that dosing with ICS at the onset of asthma symptoms may provide a buffer, helping to prevent exacerbations. 3
I’ve done a brief stint on SMART and it wasn’t for me. It was nice to “top up” doses mid-day, but I personally didn’t notice significant differences in my breathing, and, as Symbicort is available only as a Turbuhaler in Canada (and I believe of the rest of the world), I didn’t prefer this device. I also personally prefer my separate rescue inhaler, but I don’t really have justification for this—it’s just preference. As well, more severe asthmatics using SMART may also have to carry two inhalers anyways, Symbicort and a regular rescue inhaler, in the event they need more rescue medication than SMART guidelines allow--generally, more recent research is looking into SMART for milder asthmatics, even those with intermittent asthma.
Why a SMART-type regime has not been adopted by other formoterol-containing medications, I am not sure—part of me feels that the developer of Symbicort SMART may have a patent on this dosing methodology, and once that patent expires, this method may be rushed for approval with other fluticasone-containing meds. It’s certainly a well-rounded theory to treat both causes of asthma symptoms upon the onset of acute symptoms, and it works well in many ways for many patients.
Do you live in a country where SMART is approved? Have you tried it?
Does cold weather impact your asthma?