How genes are interconnected with drug metabolism and pediatric pain may impact management and perception.
During the 40thNational Conference on Pediatric Health Care in New Orleans, Cheryl Mele, MSN, DNP, PNP, AC/PC-BC, NNP-BC discussed the genes interconnected with drug metabolism and pediatric pain management/perception.
In her presentation “Pharmacogenomics in Pediatric Pain Management, Myth or Reality?” Mele describes cytochrome p450 enzymes, which are primarily found in liver cells and are responsible for metabolizing drugs commonly found in pain management, including opioids.
According to Mele, a patient’s genetic makeup will inform their drug metabolism, thereby placing them in 1 of the following categories: Ultra rapid metabolizer (UM); Extensive (Normal); Intermediate metabolizer (IM); or Poor metabolizer (PM). Depending on their categorization, a patient may absorb a drug too quickly or not at all. Therefore, it is important to assess a patient’s CYP genetic makeup before prescribing or administering drugs for pain management.1
Furthermore, pro-drugs, such as codeine, will have a different drug metabolism capability than an active drug, like morphine. For example, codeine requires the activation of CYP2D6, a cytochrome p450 enzyme,1in order to exert its analgesic effect. However, due to genetic polymorphisms, approximately 2-10% of the population cannot metabolize codeine, and are resistant to analgesic effects.
Therefore, if a health professional does not conduct necessary genetic testing, a patient may have serious negative adverse effects, including a higher risk of mortality, Mele said.
Genetics also plays a role in pain reception and should be taken into consideration when prescribing or administering morphine. According to Mele, an allele within a patient’s genetic code is protective against pain. Those with 1 allele genotype require 93% higher morphine dose compared to those with another allele genotype.
In order to identify CYP genetic polymorphisms, Mele suggests a Roche Ampli-clip. This tool retails for approximately $300, she said, and is used to guide health care professionals to prescribe or administer proper medication. She also suggests that health care professionals consult the Clinical Pharmacogenomics Implementation Consortium for clinical guidelines involving dose adjustment and alternative medications.
“Just because there are individuals with the genetic code for these pain management drugs, does mean that there will be symptoms, therefore [assessment] needs to be on an individual basis,” says Mele. “[The goal] is always the right patient, and the right drug, but also the right gene makeup.”
Mele C. "Pharmacogenomics in Pediatric Pain Management, Myth or Reality?” Presented at: 40th National Conference of the National Association of Pediatric Nurse Practitioners. New Orleans, LA. March 7-10, 2019.