medwireNews: Both over-the-counter gel-based and saline nasal sprays reduce the duration of respiratory illness reported by adults compared with usual care, show the results of the large, randomized Immune Defence study.
Furthermore, participants assigned to use either type of nasal spray used fewer antibiotics over a 6-month period than those who received usual care, as did those who were assigned to complete a brief behavioral intervention in the form of a website promoting physical activity and stress management.
“Most people have a respiratory illness each year,” and the majority of those attending a general practitioner practice are prescribed antibiotics, write Paul Little, from the University of Southampton, UK, and colleagues in The Lancet.
They continue, saying that “[e]ffective, low-cost, non-prescription interventions are needed to reduce symptom burden and antibiotic use,” adding that modifying the nasal environment is a known strategy to shorten duration of respiratory infections and that perceived stress and negative emotions can “increase susceptibility to subsequent illness.”
The team randomly assigned 13,799 adults aged 18 years and older (mean age 61–62 years) who had at least one comorbidity or factor that increased their risk for adverse outcomes from respiratory illness (including heart disease, asthma, diabetes, or stroke) or who had at least three respiratory tract infections in a normal year to receive one of four self-administered treatment groups. Participants filled out monthly and 6-monthly surveys recording the total number of days of acute respiratory illness they had experienced in the preceding periods.
The usual care group (n=3451) received brief advice about managing respiratory illnesses, including direction to an online resource and were asked not to use any over-the-counter nasal sprays.
The gel-based nasal spray, used by 3448 participants, contained a polymer to trap viruses and pH buffers. The saline spray was used by 3450 participants and had a pump action like the gel-based spray but did not have potential active excipients (eg, zinc or copper). The patients were at liberty to use treatment up to six times daily (two sprays in each nostril) at the first sign of illness, after potential infection exposure, and/or after prolonged exposure to someone with known respiratory illness until symptom-free for 2 days.
Those in the behavioral website intervention group (n=3450) accessed online material explaining how physical activity and stress management can help prevent respiratory illness, alongside learning modules to support these elements.
Of the 11,612 individuals with data available, those in the nasal spray treatment groups reported fewer days of respiratory illness during the previous 6 months than their counterparts in the usual care group, at a mean of 6.5 days in the gel-based spray group and 6.4 days in the saline spray group versus 8.2 days in the usual care group.
This resulted in significantly reduced incidence rate ratios (IRRs) relative to usual care of 0.82 and 0.81 for the gel-based and saline spray groups, while the behavioral intervention group had a nonsignificant IRR of 0.97, report the researchers.
Little and team note that despite concerns for potential irritation of the upper respiratory tract from nasal sprays, there were a significantly fewer number of days of self-reported “moderately bad” symptoms in all the intervention groups at 6 months compared with usual care, at a mean 2.4 and 2.3 for the gel-based and saline nasal spray groups, respectively, and 2.6 for the behavioral intervention group versus 3.0 for the usual care group.
Furthermore, the number of courses of antibiotics used by individuals in all three treatment intervention groups was significantly lower than that used by participants who received usual care, with respective IRRs of 0.65, 0.69, and 0.74.
Little and team point out that “[t]he reduction in antibiotic use and workdays lost was small in terms of absolute benefit, but considering these are interventions that could be implemented at a population level, this could have a large effect for the population.”
In a comment on the findings, Evangelos Giamarellos-Bourboulis (University of Athens, Greece) remarks that “[t]o tackle the issue of antimicrobial resistance, the amount of antibiotics prescribed will need to be reduced.”
He continues: “Little and colleagues show how such reductions could be achieved through simple measures and they should be congratulated for their effort,” adding that at least part of the problem of excess consumption could be solved through “education, explanation and training of patients.”
The selection of patients at high risk for developing respiratory illness in this study is a “real novelty,” says Giamarellos-Bourboulis, concluding that “symptomatic or proactive treatment with nasal sprays and proper patient education are fundamental.”
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Lancet 2024; doi:10.1016/S2213-2600(24)00140-1
Lancet 2024; doi:10.1016/S2213-2600(24)00168-1
