Over the past few months, the Tamil Nadu government has been distributing a brown herbal decoction at street corners, bus stops and railway stations in an attempt to combat the surge of dengue and fever cases across the state. The decoction is a Siddha medicine made from nine herbs and is called nilavembu kudineer.

Both the Union Ministry of AYUSH and the Tamil Nadu government have issued health advisories recommending nilavembu kudineer in small daily doses both to prevent getting dengue infection and to manage symptoms in infected people. In fact, Tamil Nadu health authorities have been distributing the medicine as a treatment for dengue for several years, including in the aftermath of the floods that ravaged Chennai and many parts of Tamil Nadu in 2015.

But there are significant doubts about the efficacy of the medicine, whether it induces any side-effects, and whether there is enough public awareness that it is not a substitute for standard allopathic management of the viral infection.

As per standard allopathic practice, there is no cure for dengue and treatment consists of managing symptoms until a patient recovers. The government advisories promoting the use of nilavembu kudineer also indicate that the Siddha medicine is meant to control symptoms and is supposed to work as an antipyretic (a substance that reduces fever) and an analgesic (substance that reduces pain). The Siddha advisories also mention the use of papaya juice, a common home remedy that is supposed to increase blood platelet count.

The science behind it

Siddha practitioners at the National Institute of Siddha in Chennai say that they started distributing nilavembu kudineer as a treatment for fevers 13 years ago. In 2013, Siddha researchers from the institute conducted a study in which they looked at groups of people with and without fever who visited a hospital at the institute and asked them if they had taken the the herbal medicine. Based on the information, the authors of the study concluded that the “analysis including all these subjects as Nilavembu taken group shows reduced preventive effect of the drug. When more than five days taken group is considered, the effect of Nilavembu has increased significantly against the development of viral fever related conditions (sic).”

M Subramaniam, senior researcher at the institute who co-authored the study, said, “The Tamil Nadu government has used that as a basis for declaring nilavembu kudineer to be used to tackle dengue.”

But a critique of the study shows how the authors might have not used the appropriate methodology to test for a medicine and that the study has been poorly designed.

Vijayprasad Gopichandran, assistant professor of community medicine at ESIC Medical College and Post Graduate Institute of Medical Science and Research in Chennai, notes that this is a case controlled study, the design of which is suitable to understanding risk factors of a disease and not to testing the protective, preventive or therapeutic effect of a drug or medicinal herb.

He also points out that there are confounding factors that might have affected the analysis. For instance, the authors report that the group without fever has a greater probability of having consumed nilavembu kudineer but it is also likely that this group came from an area with a smaller burden of dengue, less mosquito breeding, better socio-economic status or greater awareness on preventing mosquito bites.

“It is not clear whether the two groups – the fever group and the control group – were comparable in all these factors,” noted Gopichandran, in a written analysis of the study. “Therefore, one cannot definitively say whether the difference in fever between the two groups was purely due to nilavembu kudineer.”

Moreover, all patients were recruited from the Siddha hospital outpatient department and their shared purpose in being there may have biased the findings.

“Ideally, [the study] should have been done in the community, where there are diverse types of people with and without fever,” said Gopichandran. “Some who believe and take Siddha medicines regularly, and some who don’t.”

Patients and visitors at the National Institute of Siddha. (Photo: Vinita Govindarajan)
Patients and visitors at the National Institute of Siddha. (Photo: Vinita Govindarajan)

In a section within the study, the authors report that the platelet counts of 10 patients with confirmed dengue increased when they were treated with nilavembu kudineer. But since there is no comparison to this small sub-study, it provides no compelling proof that the herbal medicine what changed the course of these 10 people’s illnesses.

Gopichandran says that the way evidence or proof of treatment is understood in Siddha is different from the way it is understood in modern medicine. At the same time, he observes that compelling proof of the efficacy of nilavembu kudineer to treat dengue can be achieved only with a randomised controlled trial in which there are two groups of patients with dengue that are comparable in all aspects other than the treatment given to them. Each group would need to be tested with either nilavembu kudineer or modern medicine. Only then any observed change can be attributed purely to nilavembu kudineer.

Another serious problem with the study is that it was published in the International Journal of Pharmaceutical Sciences and Research, which has been found to be a predatory journal, and thus raises questions about the credibility of the science.

A predatory journal is a term for a journal that capitalises on the pressure on scientists to constantly publish research papers by charging a fee for an article to be published, like many other good quality journals do for processing and to make their material open access, but the article may not be checked for quality or reviewed by the journal’s editors and peers in the field.

“The National Institute of Siddha have managed to publish most of their articles only in predatory journals,” said GS Seethapathy, a PhD candidate at the School of Pharmacy and Natural History Museum, University of Oslo who is researching predatory publishing.

Patients line up at the noi naadal or pathology counter at the National Institute of Siddha. (Photo: Vinita Govindarajan)
Patients line up at the noi naadal or pathology counter at the National Institute of Siddha. (Photo: Vinita Govindarajan)

Side effects?

Other doctors have also cautioned against using the nilavembu kudineer as some studies have shown possible side effects, including infertility.

Research from the Memorial Sloan Kettering Cancer Centre in the United States indicates that the herb Andrographis paniculata, which is one of the main ingredients of nilavembu kudineer, interferes with the action of chemotherapy and of blood pressure drugs. It also warns that people on anti-platelet drugs, which prevent the formation of blood clots and occurrence of heart attacks, must use Andrographis with caution.

However, none of the government advisories on nilavembu mention possible risks or side effects.

Dr V Bhanumathi, director of National Siddha Institute, said that in the 13 years that the institute has been distributing the herbal medicine, there have been no reported side effects. She alleged that the problem lay with private hospitals making nilavembu kudineer that often did not follow the Siddha guidelines to make the decoction.

“Many private hospitals prepare a decoction that is light orange in colour,” she said. “That is not how it should look. It won’t be effective if prepared in the wrong manner. The decoction preparation method is designed by our great siddhars.It has to be consumed under the guidance of qualified Siddha doctors.”

Debate among doctors

According to The Times of India, a five-member committee from the union government that visited the state to investigate the dengue outbreak said that mass treatment with nilavembu was not recommended. They said it was not the “standard treatment”, without expanding further.

However, Bhanumathi said that the fact that the government has encouraged the supply of nilavembu in all allopathic hospitals in the state is proof of its scientific validity. “Some persons are not able to tolerate the fact that people are moving towards Siddha treatment,” she said. “Will any government come forward to promote this without evidence?”

Despite the defence of the use of nilavembu kudineer by the National Siddha Institute and the Tamil Nadu health minister, others including the Tamil Nadu chapter of the Indian Medical Association have been calling for scientific validation of the herbal medicine.

“Many more trials need to be conducted to understand the consequences and side-effects of nilavembu,” said Dr A Anna, a doctor in Avadi, Chennai. “In general, a lot of people are turning to nilavembu seeking relief for fever, so the government must take the responsibility to explain these consequences and side effects.”