For those of you who aren’t aware, I am on a mission to debunk at least a small part of Shoppers Drug Mart. This time, it’s Boiron’s Stodal cough mixture.
I hadn’t heard of Stodal before. Apparently it “relieves all types of coughs”, which seems like a pretty bold (and evidence-based claim). This surprised me as it is produced by Boiron, a homeopathic manufacturer. Now there are lots of perfectly good cough medicines out there, even if some of them taste like you’re drinking the products of a high school chemistry experiment. So what does Boiron bring to the table?
What’s in it?
Here are the ingredients:
- Antimonium tartaricum 6CH (antimony potassium tartrate, a poisonous crystalline compound used in medicine as an expectorant and in the treatment of parasitic infections, such as schistosomiasis)
- Bryonia 3CH (Bryonia is a genus of plants in the cucumber family and commonly know as bryony)
- Coccus cacti 3CH (ground-up Dactylopius coccus (previously named Coccus cacti), the cochineal beetle from which the dye cochineal comes). In case you were wondering what these look like, here are a bunch on an Opuntia cactus:
- Drosera MT (Drosera is a genus of sundews, carnivorous plants)
- Ipecacuanha 3CH (Cephaelis ipecacuanha, commonly known as ipecac, an American shrub)
- Pulsatilla 6CH (Pulsatilla is a common genus of wildflower)
- Rumex crispus 6CH (Rumex crispus is curled dock, a flowering plant)
- Spongia tosta 3CH (sponges of the species Euspongia officinalis (like the kind you wash with) which are baked in a drum – hence “toasted”)
- Sticta pulmonaria 3CH (Lobaria pulmonaria, a lichen)
So we have a syrup made from several different herbs and plants, a lichen, a poisonous chemical, and ground-up beetles. Sounds interesting. The amounts are pretty precise and this is a fairly complex blend of ingredients so there must be pretty good evidence for efficacy, eh?
Does it work?
Well a PubMed search for “stodal” brings up nothing but three articles authored by a guy called Horst Stodal, so it appears that there have been no studies of the treatment as a unit. So what about the ingredients? It turns out that there has been some work done on the constituents of the medicine:
Antimonium tartaricum – This is better known as “tartar emetic” or antimony potassium tartrate. This compound has a use in modern medicine, but I could not find anything to do with coughs. Antimony-based compounds have traditionally been used to combat onchocerciasis (river blindness) (Barrter et al., 1948) and schistosomiasis (Farid et al., 1972). Both diseases are caused by small worms and antimony has been shown to have some effect in their treatment (although modern drugs are far superior). Antimony potassium tartrate is still used as the first-line treatment for leishamaniasis, a nasty disease caused by a protozoan that is transmitted by sandfly bites. However, the treatment itself is a poison which causes excruciating pain. The only paper on a homeopathic preparation of antimony potassium tartrate (and the only PubMed result from a search for “Antimonium tartaricum”) was a methodological paper developing a mechanism for measuring concentrations of the chemical in homeopathic preparations (Gallignani et al. 2005).
Bryonia – In contrast, bryonia has received some attention as a homeopathic medical intervention. Searching for “Bryonia clinical trial” gives six results.
- Paris et al. (2008) found no effect of bryonia in combination with three other homeopathic treatments on the use of morphine following knee ligament reconstruction. 158 patients were randomly assigned in a double-blind study to homeopathic remedies, placebo or no intervention. Homeopathy performed no better than placebo.
- Murali et al. (2006) conducted a randomised, double-blind, placebo-controlled trial of a herbal remedy involving bryony, drosera and ipecacuanha on the symptoms of chronic obstructive pulmonary disease. Essentially, this is reduced lung capacity and laboured breathing. The study involved 105 patients aged between 35 and 85 all of whom had smoked at least the equivalent of 20 cigarettes per day for 20 years. The patients were placed into either “biomedical” (i.e. conventional) treatments, herbal treatment or placebo treatment. The results suggested that the herbal treatment was superior to either the placebo or the biomedical treatment. However, the sample sizes in each treatment were small and there is a suggestion of higher levels of baseline problems in the herbal group. The table below illustrates the problem. The baseline values for five out of seven measures are greater in the herbal group (DCBT1234-Lung KR). Thus, despite the fact that the dyspnoea is lower in the biomedical group at the end of the trial, this does not constitute a significance considerable improvement. Similarly, both biomedical and herbal treatments reduce wheezing to zero but this is not significant in the biomedical group because of the low baseline data. That said, the evidence for the herbal treatment does appear reasonable in the other cases.
- The inclusion of the third study is slightly irreverent on my part… Vickers et al. (2001) set out to test whether or not homeopaths could tell the difference between homeopathic remedies and placebo. 50 homeopathic practitioners in the UK were recruited. The study was randomised and double-blind. Practioners were given a one week course of one treatment (placebo or bryonia), a two week “wash-out” period to allow the treatment to leave their system and then a further one week period on the other treatment (placebo or bryonia). Sure enough, the homeopaths performed no better than chance at identifying the homeopathic remedy.
- The fourth study is actually a follow-up to the third. McCarney et al. (2002) conducted a study to investigate whether homeopaths could use dowsing to identify homeopathic preparations. Six qualified, practising homeopaths who used dowsing in their practice were asked to pick the preparation of bryony 12C from a pair of bottles where the other bottle contained a placebo. Each homeopath judged 26 pairs of bottles. Unsurprisingly, they performed no better than chance…
- Cornu et al. (2010) studied a combination of arnica montana and bryonia looking for benefist in avoiding bleeding, pain, inflammation, and myocardial ischaemia following heart valve surgery. They used 96 patients randomly allocated to placebo or homeopathy. Sure enough, there was no difference between the two treatments.
- Berrebi et al. (2001) studied the effects of bryony and apis mellifica on post-partum lactation. This is a problem that is currently treated with unpleasant medications. The study used 71 patients, with a double-blind, placebo controlled design. The results are difficult to interpret because few details are given and I would like to see more statistical information, but they demonstrate a significant benefit to homeopathy over placebo.
- The final study wasn’t available online, so I will have to go on what the abstract describes… Panossian et al. (1999) describe a study involving athletes who were given bryony and Schisandra (a Chinese herb) prior to heavy exercise. The athletes (sample size uncertain) who were given the herbs had higher levels of nitric oxide in their saliva prior to exercise and low levels after exercise compared to a placebo group. Nitric oxide has a range of beneficial effects on the body, increasing blood flow and reducing inflammation.
Summary: A few small trials show promising results for Bryony for post-partum lactation and serious respiratory disease.
Coccus cacti – The only studies looking at cochineal were interested in allergies to dyes, there is no evidence for its efficacy in treating symptoms of coughs.
Drosera – This plant is a good example of ethnobotany contributing something truly useful to medicine. Chemicals contained within sundews have been shown to have antimicrobial effects on a range of bacteria, including those causing respiratory infections (Didry et al., 1998). Drosera species have been used in folk medicine for centuries, and a lot more details are given by Babula et al. (2009, available here). However, despite some in vivo work done demonstrating anti-spasmodic and anti-inflammatory properties, there is no clinical trial data by which to evaluate the efficacy of these treatments.
Ipecacuanha – Ipecac is another product of ethnobotany. Ipecac is an Amazonian medicinal plant, the roots of which are used as an expectorant (clears mucous), an emetic (makes you vomit) and an amoebacide (kills amoebae, small single-celled organisms some of which can cause disease). It was regularly used as an emetic (to induce vomiting) until the early 20th Century but its use is now not recommended as their are far better contemporary treatments. There are a lot of PubMed articles on ipecac, mostly relating to emetics or the biology of the plant. Searching for “ipecacuanha homeopathy” reveals three results. One of these is a chemical analysis of ipecac mother tincture and the other two document the use in the treatment of mastitis in cattle (Varshney and Naresh, 2004,2005). Conclusion: might help if you have swollen udders…
Pulsatilla – A search for “pulsatilla clinical trial” yields three results. Friese et al. (1997, available here) conducted an observational study (no placebo, no blinding, no randomisation…) on the treatment of otitis media (middle ear infection). 131 children were involved, of which 103 underwent homeopathic treatment and 28 underwent conventional treatment. Both treatments were tailored to the child’s symptoms, with homeopaths selecting from among 12 remedies. The results showed some promise for the homeopathic approach, but this was not separated from placebo. The authors spend the first four paragraphs of the discussion defending their shoddy experimental design. The second trial looked at Eviprostat which is a treatment for benign prostatic hyperplasia (enlargement of the prostate) (Tamaki et al., 2008). However, this study only compared two medicines with different doses of the herbal remedies (including Pulsatilla) and so nothing can be said about its efficacy vs placebo. The third study is a discussion piece published (in German) in a German veterinary journal… The abstract mentions that a homeopathic remedy involving Pulsatilla was no better than conventional remedies at improving the puerperal period or fertility after retention of placenta (in cows, I presume). No evidence of efficacy here.
Rumex crispus – There seems to be evidence that R. crispus leaves have antioxidant and antimicrobial properties (Yildirim et al., 2001), although the benefits of antioxidants have been disputed. However, there was no clinical trial data involving this remedy and no research published on its role in dealing with coughs.
Spongia tosta – This one is just a bit silly, there are no results on PubMed for “Spongia tosta”.
Sticta pulmonaria – There is one clinical trial published on Lobaria pulmonaria (as part of a combination homeopathic remedy) as a treatment for sinusitis (Adler, 1999). This was an open-label study (the opposite of double-blind, where both experimenter and patient know what they are getting), there was no placebo or comparison of any kind. The study reported that most people got better within a certain span of time. This study says nothing about clinical efficacy.
I have tried to provide a fairly comprehensive view of the medicinal ingredients of this drug. These vary from folk medicine (Drosera, Ipecacuanha) to Victorian medicine (Antimonium tartaricum) and finally to just plain weird (beetles?). There is some limited evidence for some of the constituents having some medicinal effects. Of these, only Drosera could reasonably be considered for a cough medicine, given that it may have some anti-inflammatory properties. What is needed is a large, randomised, placebo-controlled, double-blind trial for Stodal that could demonstrate efficacy against placebo and relative to conventional medicine. As a final point, we are often told that homeopathy is fantastic because it is really individualised and tailored to the needs of the patient. Why on earth are they selling it over-the-counter, then!? More to come…
Post 1: Introduction
Post 2: Stodal, by Boiron
Adler M. 1999. Efficacy and safety of a fixed-combination homeopathic therapy for sinusitis. Adv Ther 16: 103-111.
Babula P, Adam V, Havel L, Kizek R. 2009. Noteworthy Secondary Metabolites Naphthoquinones – their Occurrence, Pharmacological Properties and Analysis. Current Pharmaceutical Analysis 5: 47-68.
Bartter FC, Burch TA, Cowie DB, Ashburn LL, Brady FJ. 1948. Experimental therapy of onchocerciasis with trivalent antimonials. Annals of the New York Academy of Sciences 50: 89-96.
Berrebi A, Parant O, Ferval F, Thene M, Ayoubi J-M, Connan L, Belon P. 2001. Traitement de la douleur de la montée laiteuse non souhaitée par homéopathie dans le post-partum immédiat. Journal de Gynécologie Obstétrique et Biologie de la Reproduction 30: 353.
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Panossian AG, Oganessian AS, Ambartsumian M, Gabrielian ES, Wagner H, Wikman G. 1999. Effects of heavy physical exercise and adaptogens on nitric oxide content in human saliva. Phytomedicine 6: 17-26.
Paris A, Gonnet N, Chaussard C, Belon P, Rocourt F, Saragaglia D, Cracowski JL. 2008. Effect of homeopathy on analgesic intake following knee ligament reconstruction: a phase III monocentre randomized placebo controlled study. British Journal of Clinical Pharmacology 65: 180-187.
Tamaki M, Nakashima M, Nishiyama R, Ikeda H, Hiura M, Kanaoka T, Nakano T, Hayashi T, Ogawa O. 2008. Assessment of clinical usefulness of Eviprostat for benign prostatic hyperplasia–comparison of Eviprostat tablet with a formulation containing two-times more active ingredients. Hinyokika Kiyo 54: 435-445.
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Varshney JP, Naresh R. 2005. Comparative efficacy of homeopathic and allopathic systems of medicine in the management of clinical mastitis of Indian dairy cows. Homeopathy 94: 81-85.
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Yildirim A, Mavi A, Kara AA. 2001. Determination of Antioxidant and Antimicrobial Activities of Rumex crispus L. Extracts. Journal of Agricultural and Food Chemistry 49: 4083-4089.