Pharmacogenomics and Patient Treatment Parameters to Opioid Treatment in Chronic Pain: A Focus on Morphine, Oxycodone, Tramadol, and Fentanyl.
OBJECTIVE
Opioids are one of the most commonly prescribed medicines for chronic pain. However, their use for chronic pain has been controversial. The objective of this literature review was to identify the role of genetic polymorphisms on patient treatment parameters (opioid dose requirements, response, and adverse effects) for opioids used in malignant and nonmalignant chronic pain. The opioids that this review focuses on are codeine, morphine, oxycodone, tramadol, and fentanyl.


METHODS
A literature search of databases Medline and Embase was carried out, and studies up to April 2016 were included in this review. Studies were included based on a combination of key words: chronic pain and related terms, pharmacogenetics and related terms, and opioids and related terms.


RESULTS
Among the 1,408 individual papers retrieved from the search in Medline and Embase, 32 original articles were included in this review, with none related to codeine. The 32 papers reported various study designs, opioids, and polymorphisms being studied for associations with treatment outcomes. This literature review reveals that variants in ABCB1, OPRM1, and COMT have been replicated for opioid dosing and variants in ABCB1 have been replicated for both treatment response and adverse effects.


CONCLUSIONS
Currently, there are few validated studies to form a strong evidence base to support pharmacogenomics testing when initiating opioid therapy. However, the field of pharmacogenomics in chronic pain is likely to expand over the coming years, with the increasing number of treatment options available and larger cohorts being assembled in order to identify true associations.
School of Pharmacy and Medical Sciences and Sansom Institute for Health Research.
Renae A
RA
Lloyd
School of Pharmacy and Medical Sciences and Sansom Institute for Health Research.
Elizabeth
E
Hotham
School of Nursing and Midwifery.
Catherine
C
Hall
School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia.
Marie
M
Williams
School of Pharmacy and Medical Sciences and Sansom Institute for Health Research.
Vijayaprakash
V
Suppiah
D000701:Analgesics, Opioid / Q000627:therapeutic use*; D059350:Chronic Pain / Q000188:drug therapy* / Q000235:genetics*; D005283:Fentanyl / Q000627:therapeutic use; D006801:Humans; D009020:Morphine / Q000627:therapeutic use; D010098:Oxycodone / Q000627:therapeutic use; D000071185:Pharmacogenomic Testing; D000071184:Pharmacogenomic Variants / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D014147:Tramadol / Q000627:therapeutic use
D000701:Analgesics, Opioid; D014147:Tramadol; D009020:Morphine; D010098:Oxycodone; D005283:Fentanyl
Chronic Pain; Malignant; Nonmalignant; Opioids; Pharmacogenetics; Pharmacogenomics