Does homeopathic medicine have a preventive effect on respiratory tract infections? A real life observational study

The main focus of this retrospective observational study was to explore the effect of the specific extract of duck liver and heart in the prevention of RTIs, by comparing two groups of patients, one that took the medicine and the other that did not.

The results indicate that the evaluated homeopathic drug has a preventive effect on the onset of RTI episodes. Although the role of this drug has been vividly debated, the protective effect observed here is consistent with other studies that have documented its effect on the treatment of flu and flu-like symptoms [9, 20–22]. Thus, our findings add to the growing body of knowledge that could ultimately indicate this homeopathic medicine as a beneficial preventive treatment of RTIs [6].

Moreover, observational data from real-life homeopathic practice are becoming increasingly useful to evaluate the role of this type of IM in treating a wide range of chronic and acute diseases. These results should not be underestimated, also because any gain in health offered by homeopathic medicine, alone or in combination with standard medicine, could be considered of value to the healthcare system in managing the yearly seasonal epidemics that cause RTIs each winter.

An analysis of recent data (2014) of winter all-cause mortality collected by 14 EU countries showed excess mortality levels higher than those seen in the past three winters, especially among older people; these deaths were likely related to RTI [23].

With respect to the analysis of the cohort baseline characteristics, our results indicate that the patients included in the treated group were younger and had more episodes of RTIs during the year before inclusion in the study compared to subjects in the untreated group, whereas the province of residence, gender, smoking habits and distribution of respiratory pathologies were similar for the two groups.

During the observation period, patients treated with the homeopathic medicine had a lower number of respiratory tract infection episodes than untreated patients. In particular, we found that untreated patients who had a mean of 4–5 episodes of exacerbation the year before the study maintained a mean of 2 or less episodes of exacerbation during a subsequent 10-year follow-up without any preventive treatment. It should be pointed out that the values of 4–5 episodes of exacerbation were observed when the patients did not attend the medical consulting while during the study the observed patients had various concomitant pathologies and concomitant pharmacological treatments which were adjusted by the practitioner – for each individual clinical case of both groups – as a function of the patient’s short and long-term medical history. Thus the reduction in the number of infections also among patients in the control group can be accounted for by various factors such as the optimisation of the background therapy. In fact, often, allergic subjects were not following any kind of therapy or asthmatics were not following a bronchodilator background therapy before entering in the study.

The reduction in the mean number of RTI episodes during the observation period versus the mean number of RTI episodes in the year before inclusion in the study was statistically higher in the group of patients treated with the homeopathic medicine than in the untreated group. Both these observations indicate a possible preventive effect of the homeopathic medicine on the onset and development of RTIs.

Importantly, the greater reduction in RTI episodes for the treated group during the overall treatment, compared to patients belonging to the untreated group, was evident irrespective of gender, smoking habits, or the profile of concomitant respiratory diseases. However, the situation for age class distribution was different. Patients treated with specific extract of duck liver and heart did have a greater reduction in the average infectious episodes during the study compared to the year before inclusion than did patients of the untreated group, independently of what age class they belonged to. However, age may have nevertheless played a role in reducing RTI episodes among the treated patients, since the reduction in episodes among these patients seemed greater for patients less than 18 years old (particularly in the 3-5 year age class). This observation is consistent with the pathophysiology of RTIs which are much more prevalent in paediatric/adolescent age than in adults. The exact mechanisms responsible for these observed effects are not clear yet. The literature suggests that ultra-molecular homeopathic dilutions (such as specific extract of duck liver and heart) may exert their effects through a peculiar water structure. However, more evidence of this is needed [24, 25].

This study has several limitations. One particular issue is its observational design which, as documented elsewhere [26], is susceptible to inherent biases associated with the collection of non-random data. In addition, the use of an untreated control group, rather than a placebo-treated one, might be questionable. In this connection, it should be noted that a Cochrane meta-analysis on this same medicine [27] could not give a robust conclusion on the effectiveness of Oscillococcinum owing to the quality of the analysed studies; however, from the report it emerged that those studies had found this homeopathic medicine to have a therapeutic effect for the treatment of influenza-like illness that was different from placebo. The present study shows a snapshot of the use and therapeutic potential of this homeopathic medicine in a real-world, and the results we have found need to be confirmed by large randomized controlled studies. As regards the preventive effect of this medicine, the cumulative result of the meta-analysis was protective but did not reach the statistically significant limit (overall risk ratio (RR)?=?0.48; 95 % CI?=?0.17–1.34). It should be considered that only two studies were available for the meta-analysis [28, 29], and that in both the RR was found to be protective. In particular, the first study [28] reported a very low RR value of 0.15 (indicating 85 % reduction in the risk of getting sick) although the statistically significant limit was not reached; most likely, this can be attributed to the low number of events (n?=?50 patients in each group) which “enlarged” the confidence limits. The RR was also protective in the second study (which evaluated 110 Oscillococcinum-treated and 117 placebo-treated patients) [29] and proved statistically significant, although it was less noticeable than the RR of the first study (RR?=?0.62; thus a risk reduction of 38 %). Conversely, the main strength of this study is that it provides objective data on the effects of homeopathic care for a frequent and self-limiting condition, for which the use of antibiotics is often ineffective or even inadvisable [30], in a fairly large number of patients. While there is still not enough robust evidence that homeopathic medicine has an effect on RTIs (thus, further controlled, randomized studies are needed), the potential benefits of homeopathic care in reducing antibiotic consumption has been noted [31, 32]. A nationwide French survey of 518 adults and children with upper respiratory tract infections (URTIs) compared antibiotic and antipyretic/anti-inflammatory drug usage, URTI symptom resolution and occurrence of potentially-associated infections in patients in care with practitioners having different levels of prescribing preferences (i.e., homeopathic, general or mixed practice). The results of this study indicated that patients followed by homeopathic practitioners showed significantly lower consumption of antibiotics and antipyretic/anti-inflammatory drugs with respect to those treated by general or mixed practice practitioners, but still had a similar evolution in related symptoms [30].

Finally, it should be pointed out that the evaluation of any medical intervention should take into account not only therapeutic efficacy, but also other factors such as adverse events, costs and compliance. In this observational study the patients treated with the preventive homeopathic medicine reported no adverse reactions, and none of these patients has ever shown and/or reported discomfort in tolerating this homeopathic medicinal product during the period of observation.