BRAZIL: Child-Adapted Formula to Deal Major Blow to Chagas Disease

  • by Fabiana Frayssinet (rio de janeiro)
  • Inter Press Service

The new paediatric dosage form of benznidazole, which has just been approved for registration by Brazil's National Health Surveillance Agency (ANVISA), was developed by the Pernambuco State Pharmaceutical Laboratory (LAFEPE) with the support of the Drugs for Neglected Diseases initiative (DNDi).

'Until recently, children's treatment had to be improvised rather haphazardly by dividing up adult-sized pills' available only in 100 milligram tablets, Dr Isabela Ribeiro, head of DNDi's Chagas Clinical Programme and manager of the paediatric formulation of benznidazole, told IPS.

'The new medication has the potential for making a huge positive impact on the treatment of newborns and children up to two years old, or weighing up to 20 kilos,' she said.

Dividing a benznidazole tablet for adults into up to eight fragments, crushing them and mixing them in water, is an unsatisfactory and potentially unsafe process for treating infected children. Parents, often uneducated, have to do this twice a day for 60 days to complete their children's treatment, frequently in unhygienic conditions and without access to clean water.

'As well as increasing the difficulty of an already very long treatment programme, there is a real possibility of administering improper doses,' she said. A larger dose than required increases the risks of side-effects, and too small a dose could make the treatment ineffective.

The new formulation, called LAFEPE Benznidazole 12.5 mg, in contrast, is easy and safe to use.

As Ribeiro described, it comes in 12.5 mg tablets that are easily dispersed in water, orange juice or milk. The recommended dose is from one to three tablets a day, depending on the infant's body weight.

Administering precise doses will minimise the risks of involuntarily giving too much or too little medication, and will avoid treatment interruptions.

'We also hope there will be a gradual increase in the number of children treated, when mothers and doctors feel more confident about initiating treatment with a newborn baby or infant,' she said.

According to Ribeiro, in spite of the success of prevention policies in countries like Argentina and Brazil, Chagas disease infects between eight and 10 million people, mainly in Latin America, and kills 12,000 people a year, principally from heart problems caused by the infection, making it the principal cause of parasite-induced deaths in the Americas.

The parasite responsible for Chagas disease - Trypanosoma cruzi - is mainly transmitted through the bite of a bloodsucking insect known as the 'vinchuca', which lives in crevices in the mud walls of houses in poor rural areas, where there is limited access to health services.

The parasite can also be transmitted by means of blood transfusions, organ transplants, contaminated food, and from mother to child during pregnancy.

Children are particularly vulnerable to the infection. About 14,000 children a year are born with the disease through maternal transmission.

The disease has an early acute phase, during which patients can be treated and cured with antiparasitic medicines. But if it is not detected in time, chronic illness sets in and can lead to life-threatening heart and digestive system disorders. Initial symptoms of the infection are fever, vomiting, shortness of breath and convulsions.

'Chagas disease is regarded as a children's illness because it is generally acquired in childhood, but it develops in adult life. Even in the case of transmission through the 'vinchuca' insect vector, children are the main victims,' Ribeiro said.

Treatment with benznidazole in the first year of life can completely eliminate the parasite from over 90 percent of babies infected from birth, and cure more than 85 percent of children treated before they are two years old.

Manuel Gutiérrez, head of the International Federation of Chagas Patients, said 'Thousands of mothers with babies infected with Chagas disease will welcome this treatment as more than just a pill.'

'Their voices have finally been heard,' he told the press at an international meeting on neglected diseases in early December, at the Oswaldo Cruz Foundation (FIOCRUZ).

'From now on, hope of an early cure for infection with the parasite that causes Chagas disease is a wonderful reality,' said Dr Mirta Roses Periago, head of the Pan American Health Organisation (PAHO).

The distribution of Chagas disease has changed over the years due to rural migration, and it has become an urban illness that is easy to find in the poor suburbs surrounding major cities, where the most common form of transmission is from mother to child. Many mothers only discover they have the disease when they are pregnant.

The new tablet for children will be produced by LAFEPE, the second largest public laboratory in Brazil and the sole global producer of benznidazole after acquiring the technology from Roche, the Swiss-based pharmaceutical giant.

'A public laboratory must serve the public interest,' Luciano Vazquez, the head of LAFEPE, told IPS. 'As such, we will make the product available at cost to all public health institutions and NGOs.'

Similarly, DNDi is collaborating with LAFEPE to make the drug widely available, by working to register it in Argentina, Bolivia, Colombia, and Paraguay, 'priority countries where Chagas disease prevalence is high and treatment is urgently needed,' according to a DNDi communiqué.

DNDi was founded in 2003 as a partnership between the international relief organisation Médecins Sans Frontières (MSF, or Doctors Without Borders) and public research institutions in Brazil, India, France, Kenya and Malaysia, to develop new treatments for neglected diseases in developing countries that are not profitable enough to interest large pharmaceutical companies.

In fact, LAFEPE made its commitment to producing benznidazole after Roche announced it was terminating production of the drug, Vazquez said.

Nowadays, Chagas disease is a global illness. An estimated 300,000 cases have been diagnosed in the United States and some European countries - especially Spain - and in Japan and Australia, according to MSF.

© Inter Press Service (2011) — All Rights ReservedOriginal source: Inter Press Service