Ivermectina: un medicamento de Nobel, pero poco accesible

Ivermectin: A Drug Worthy of a Nobel Prize, but Inaccessible for Those Who Need It

22.10.2015
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The Japanese scientist Satoshi Omura has recently received the Nobel Prize in Physiology and Medicine for his discovery of ivermectin more than 30 years ago. Invermectin is best known for its extraordinarily broad spectrum of activity against nematodes, the roundworms that cause a large proportion of the most common neglected diseases on our planet. It is used to treat millions of people at risk of contracting devastating diseases, such as onchocerciasis and lymphatic filariasis, and also plays an important role in the control of intestinal helminth infections. Because of its excellent safety profile and broad spectrum of activity, ivermectin is catalogued by the World Health Organisation as an essential medicine and is regarded by many as a "magic bullet" for global health. The effectiveness of ivermectin against many diseases associated with poverty makes it a candidate to be one of the next breakthroughs in global health owing to its potential for improving quality of life and reducing mortality rates in low-income countries.

However—and this is the catch—a “magic bullet” is of little use without a “magic gun”, and unfortunately ivermectin is not currently accessible to all the people in the world who need it. Since the 1980s, the pharmaceutical company Merck has provided this essential medication free of charge for the treatment of onchocerciasis and lymphatic filariasis in the areas of the world where these diseases are endemic; however, the drug is not marketed or is very expensive in most of the countries where it could be used to treat other parasitic diseases. In particular, it is not available for the treatment of human strongyloidiasis despite being considered the first line therapeutic option and the most effective treatment for this helminth infection, which affects tens of millions of people worldwide and is particularly dangerous for anyone with a weakened immune system.

One of the main reasons for the limited availability of this "magic bullet" is that the conditions it treats are what we call neglected diseases. The main characteristic of this group of conditions is that, although they affect millions of people with scant resources living in tropical and subtropical countries, very little money is invested in researching and developing tools for their treatment. Researching solutions for neglected diseases is not a commercially attractive proposition for the pharmaceutical industry because of the weak economic markets for these drugs. In the case of ivermectin, the lack of a clear financial incentive has given rise to a situation in which access to the drug is extremely limited outside of the donations restricted to certain countries for the treatment of certain diseases. In other cases, most of those who need treatment cannot afford it because the average income in affected populations is less than $2 a day.

The as yet unexplored potential of ivermectin in public health is enormous, in particular its usefulness for controlling and eliminating several neglected infectious diseases and its potential role as a tool for malaria control as it is capable of killing mosquitoes that feed on the blood of individuals who have recently been treated with the drug. Major large-scale research initiatives are needed to facilitate new applications of ivermectin and to provide evidence on its effectiveness and safety in these settings. However, the first step towards improving the lives of millions of people, particularly school age children, is to implement policies that will provide access to this essential drug at a reasonable prices for the population affected by these diseases. Only then can the full potential of Professor Omura's discovery be realised.

The global community must act to ensure that essential medicines are affordable, accessible and available to those who need them, irrespective of what disease they may have or where they were born. The aim of a campaign launched today in Madrid under the banner “It’s Not Healthy” is to help build an efficient and sustainable system for biomedical research that can ensure universal access to health care and much needed medicines.

 

Dr. Jose Muñoz is a specialist in tropical medicine at the Hospital Clínic de Barcelona and a researcher in the Barcelona Institute for Global Health (ISGlobal).