With information from Camila Maciel, from Agência Brasil
A widely used remedy for menstrual cramps – mefenamic acid (trade name Ponstan) – may be effective for treating schistosomiasis. The discovery was made by researchers from the University of Guarulhos studying drug repositioning, ie new uses for existing drugs. After undergoing laboratory tests and animal experiments, clinical trials in humans are lacking so that anti-inflammatory drugs can also be prescribed to fight worms.
The study showed that Ponstan reduced parasitic load by more than 80% in mice infected with Schistosoma mansoni. According to the researchers, this percentage exceeds the “gold standard” stipulated by the World Health Organization (WHO) for new drugs. Currently there is only one remedy for the treatment of schistosomiasis, praziquantel. The efficacy of mefenamic acid may be even greater than the available antiparasitic because it also acted in the larval phase of the parasite.
Schistosomiasis affects more than 240 million people worldwide, according to WHO data. Professor Josué de Moraes, from Guarulhos University, points out that this is a neglected disease and, although affecting a significant portion of people, lacks more advanced studies, vaccines and treatments. “We are talking about diseases of poverty. The pharmaceutical industry, when looking at this audience, will not want to develop a new drug, ”said the study author.
According to Moraes, the production of a new drug involves at least 1.5 billion years of research and, as the disease mainly affects the poor, there is no interest from the pharmaceutical industry. “The advantage of [drug] repositioning is that it is something that already exists, that has already been approved, is already available in drugstores and if we can find out that this drug has a different application than it was used, I will eliminate this stage of time and cost, ”explained the teacher.
The drug repositioning study developed at the University of Guarulhos began with the analysis of 73 non-steroids marketed in Brazil and other countries. Mefenamic acid showed the most promising results as antiparasitic. The discovery, which was supported by the São Paulo State Research Support Foundation (Fapesp), was published in the Lancet group’s EbioMedicine magazine.
The transmission of schistosomiasis is linked to places without adequate sanitation and by water contact with snails infected by the disease-causing worms. Schistosoma mansoni worms lodge in the veins of the patient’s mesentery and liver. The infected individual has no symptoms within the first two weeks, but the condition can evolve and cause chronic health problems and death.
Moraes points out that once human clinical trials have been started, if the efficacy of Ponstan for schistosomiasis has been proven, within one year the leaflets can be changed and treatment recommended. “It’s taking a region where you have people with the disease and getting treatment and monitoring the healing process. The only step left now is this. All the studies that are needed to develop medicine have been done, ”he explained.