Indian Journal of Pain

: 2020  |  Volume : 34  |  Issue : 2  |  Page : 62--64

COVID-19 will shift chronic pain management towards genetics

Helen Gharaei 
 Azargan Pain Clinic, Tehran, Iran

Correspondence Address:
Dr. Helen Gharaei
Anaesthesiologist and Pain Consultant, Azargan Pain Clinic, Vanak Sq, North Gandi St, No 26, 1st floor, Maryam Surgery Center, Tehran

How to cite this article:
Gharaei H. COVID-19 will shift chronic pain management towards genetics.Indian J Pain 2020;34:62-64

How to cite this URL:
Gharaei H. COVID-19 will shift chronic pain management towards genetics. Indian J Pain [serial online] 2020 [cited 2020 Sep 25 ];34:62-64
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COVID-19, a severe acute respiratory syndrome coronavirus-2, is spreading as a rapidly transmissible disease that currently has affected more than 200 countries. COVID-19 is a new pathogen that there is no human immunity against it. As genetics can affect a person's susceptibility to various infectious diseases,[1] it seems that it may also affect our response to this virus, and how severe the disease becomes. The scientific community has continued to create a genetic basis for phenotypic variability in individuals and different ethnic groups in terms of susceptibility to the disease as well as response to treatment. Personalized medicine is a new science to identify the optimal treatment for each patient by measuring pharmacological biomarkers and genetic profiles for each person for improving the efficacy and safety of medical treatments.[2]

The clinical manifestations of COVID-19 and the response to treatment vary from person to person and country to country, and researchers are looking at possible genetic reasons to explain why some people have more severe manifestations than others.[3] The scientists compare the DNA of the people who presented severe symptoms to those of people who had milder or even unmarked symptoms. By identifying the genetics of people who have had a serious illness, scientists may be able to understand who is the most at risk for the disease. Perhaps more importantly, these genetic studies could also help us gain new insights into how the body's cells become infected with the virus and how it affects our bodies. A specific information is required that could potentially help us to choose the best treatment and identify drugs that are effective against and even prevent COVID-19.[4] As COVID-19 weakens the immune system, some important chronic pain medications that weaken the immune system should be used with caution. Patients with chronic pain have a weaker immune system than normal people, and some medications, such as steroids or narcotics and painkillers, may weaken the immune system and/or increase the risk of the viral disease and sometimes cause respiratory failure or mimic respiratory symptoms of the virus.[5]

Can genetics help the pain specialists to identify genetically predisposed patients to COVID-19 and genetically weakened immune systems patients and whom are more susceptible to side effect of medications and/or the respiratory depression effect of drugs? Can genetics help pain specialists to personally limit pain medications during viral crises, and not deprive all chronic pain patients from medication? Today, the right drug is still chosen as a trial and error. We cannot take risks during the viral pandemic, and it is better to choose the drug and its dose based on personalized medicine. There is a great inter-individual variability in pain perception or pain relief. The complex interactions between analgesics and organisms due to different categories such as age, gender, ethnicity, stress, mood, or illness may alter pain perception. Genetic variability in drug pharmacodynamic and pharmacokinetic influences the analgesic efficacy of certain medications.[6]

Pain sensitivity varies from person to person, and there are many differences in pain threshold, and even some do not feel any pain. Sensitivity to pain and the risk of chronic pain are polygenic.[7] Patients with chronic pain are concerned about the lack of response to some of the treatments and the risks of these treatments during an epidemic. Isn't it the time for genetic to be part of the algorithmic approaches to chronic pain management and to be standardized? Many genetic studies have been performed and the effect of genes on pain sensation and change of acute pain to chronic pain in certain individuals and differences in response to drugs and the susceptibility to drug complications or addiction has been studied.[8] Pain sensation, signal transmission, and pain tolerance are complex processes that depend on many factors, such as proteins and neural networks. Therefore, any changes in gene products during these complex pathways affect the experience and treatment of pain. Knowledge of genetic issues allows for effective screening of drugs to treat inflammatory and neuropathic pain. Genes that are associated with the synthesis and the release of the neurotransmitters are all nominated for the treatment of chronic pain. Changes in these genes are effective not only in understanding the pain variable but also in the analgesic effect.[9] Rare mutations that lead to abnormal ion channel function (Nav1.9) lead to major abnormalities in the pain perception.[10] Genetic research has focused on the μ-opioid receptor. The μ-opioid receptor gene, OPRM1, has been extensively studied in connection with the various aspects of chronic pain. Notably, tricyclic antidepressants which are commonly used in pain management, are primarily metabolized by CYP2D6 and CYP3A4, which also play an important role in the metabolism of some opioids. CYP2C has a clinical relationship with metabolism and the clearance of nonsteroidal anti-inflammatory drugs. Genetic testing of CYP2D6 can avoid the negative effects of the codeine treatment and can improve the safety of pain management. Some genetic haplotypes are associated with different pain tolerance phenotypes, such as low pain sensitivity, moderate pain sensitivity, and high pain sensitivity. The haplotype associated with moderate pain sensitivity was associated with greater and longer recovery after lumbar surgery in patients with disc herniation. Genetic changes in P-glycoprotein are known to be effective in reducing adverse drug reactions and increasing the analgesic effect. Researchers have assessed the influence of various gene polymorphisms on pain perception, pro-inflammatory cytokines, drug response, and metabolism in humans with chronic pain[11],[12] [Table 1].{Table 1}

The regulation and modulation of pain perception are not yet fully understood; hence, more complex knowledge of genetic and epigenetic background before the clinical use of genetic markers will be needed to control pain. Despite the promise of preliminary data on genetic diversity in the main genes of the candidate in chronic pain and its treatment, there is insufficient evidence for the clinical application of personal medicine for the chronic pain management. However, providers should take genetic information into account when caring for people who are not responsive or deeply sensitive to treatment and the risks of these treatments during the COVID-19 epidemic. The field of medicine needs to continue its research on this field, including large-scale prospective studies that are well designed and focused on pain pathways to standardize genetic as a part of the algorithmic approaches to chronic pain management. The good news is that some of the world's largest biobanks are planning to search for genetically susceptible patients to COVID-19. These biobanks would certainly be a basis for studying personalized medicine on chronic pain management in the near future.


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