Association between CYP2C19 gene polymorphisms and analgesic response to meperidine in emergency department patients with renal colic: a prospective observational study.

backgroundRenal colic is a urologic emergency that presents with characteristic severe pain and is mostly seen in emergency services. The preferred medications are NSAIDs, paracetamol and opioids, but considering the severity of pain, opioid analgesics should be advised. The aim of this study is to determine the relationship between meperidine efficacy and CYP2C19 gene polymorphisms.

methodsThis prospective observational study was conducted between 01.07.2017 and 01.10.2018 in the Pamukkale University Faculty of Medicine Emergency Department. Our study subjects included 203 patients with renal colic and 102 individuals presenting with abdominal pain but not diagnosed with renal colic were included only for genetic frequency analysis; this group was not included in the intervention safety/efficacy analyses. 203 patients were given 100 mg of meperidine and observed 60 min later, and vital signs, laboratory values, etc., were recorded.

resultsThe age and sex distributions were similar between the case and control groups. There was no statistically significant difference between the sexes in visual analog scale (VAS) scores at any time (0.min-15.min-30.min-60.min). The normal-activity/rapid metabolizer groups had significantly lower 30- and 60-min VAS scores than did the moderate-activity groups. The percentages of VAS decreases at 30 and 60 min from baseline were significantly greater in the normal-activity rapid metabolizer group than in the moderate-activity group. This study revealed that the efficacy of the drug was not affected by age, sex or stone location. The VAS score decreased significantly at all time intervals. Additionally, the decrease in the VAS score between 0 and 15 min after drug administration was similar in each genotype group, but after 30 min, it was remarkable for the CYP2C19 1/1 genotype. During follow-up, 11 patients had drug-related adverse events (most commonly nausea and dizziness). No serious events occurred, and no additional interventions or hospitalizations were required.

conclusionsThis study suggested that the effectiveness of meperidine in treating renal colic may be influenced by the genetic polymorphism of CYP2C19 in the patient. The pain response was markedly reduced in individuals with the CYP2C19 *1/*1 genotype. The age, sex, and stone localization groups were seemingly comparable with respect to the efficacy of meperidine. It is advisable to consider the genetic profile in individualized treatment approaches, with the aim of increasing drug efficacy and optimizing dose adjustments.