Medicine and pharmaceutical companies have launched a crusade to hit on neurotransmitters involved in the feeling of pain. The move points to looking for selective painkillers able to act without disturbing any other area in the nervous system
There is not a perfect drug against pain. Not yet. As technology suggests innumerable possibilities in the area of medicine and pharmacology, just the first steps have been taken in the invention of a painkiller able both to counter pain and inhibit side effects. The International Association for Study of Pain (IAPS) defines pain as "unpleasant sensory and emotional experience, associated with an actual or potential damage of tissues."
According to duration, pain is classified as acute (less than three months) or chronic (more than three months). Based on its production mechanism, pain is classified as nociceptive (physiological; arises from the stimulation of specific pain receptors as a defense mechanism of the body in the event of injuries) and neuropathic (arises from within the peripheral and central nervous system; is generally chronic and deteriorates the quality of life). There is also acute-chronic pain.
Several investigations have found that 90 percent of the world population is doomed to suffer from lumbago (acute-chronic pain). Dr. Ariadna Rodríguez, Medical Director of Pfizer Venezuela, explained what you expect from pain therapies.
What do the latest studies provide for pain therapy?
Twenty years ago, knowledge about all neurotransmitters involved in neuropathic pain was not as wide as today. Development of more and more specialized research techniques has given the chance of knowing what happens to neurons when pain arises, and this furthers development of drugs that act more specifically in some nociceptors (pain receptors), changing or modulating neurotransmission. We have broken new ground with neurobiology and, therefore, pharmacology for pain. Formerly, drugs acted as nonselective inhibitors of neurotransmitters uptake and acted in several systems at the same time with plenty of side effects.
Is removal of adverse events the main success?
For the time being, they are not removed, but eased, because there are many drugs with specific action sites. Anyhow, as causes and symptoms are different, therapies will also vary according to the type of pain.
State-of-the-art technology for pain management. What is it for?
There is invasive treatment or treatment involving surgery intervention, such as nerve block. Intra-thecal pumps or medullar neuro-stimulation (devices directly inserted in the spine) are the newest to treat severe pain unresponsive to standard therapies.
Are they available in Venezuela?
No, in the country there is not a pain unit with intervention techniques as such. There are, though, centers such as Miguel Pérez Carreño Hospital. For quite a while they have been giving university courses on pain and conduct some operations. In the private practice, some neurosurgeons do it. However, the main hurdle is that neuro-stimulators are too expensive. An intra-thecal pump (a subcutaneous pocket full of drugs, connected to a catheter which directly delivers drugs to the spinal cord) can be as much as USD 10,000, excluding admission to hospital and inpatient treatment.
Tell me about upcoming strides in the near future.
Medicine has succeeded in identifying genetic disorders, thus preventing overproduction of sodium channels, responsible for severe pain. Nonetheless, no much headway has been made with autoimmune diseases, such as rheumatoid arthritis, in the area of pain, yet progress has been made in treatment itself. And this is wonderful, because in controlling the disease, you can prevent destruction of joints and patients from feeling pain.
Translated by Adrián Valera