New Chronic Pain Treatments in the Outpatient Setting: Review Article

Gender based differences, pharmacogenetics and adverse events in chronic pain management

Safety data in chronic non-cancer pain (CNCP) with long-term opioid therapy has been poorly studied and can be differently influenced by gender. Furthermore, pharmacogenetics (PGx) could possibly be used to tailor pain medication based on the individual's genetic background. The aim was to assess whether PGx applied to a pharmacovigilance system could help to improve a patient's security profile. A pharmacovigilance data recording system was conducted over 24 months, including genotyping of OPRM1 variants (opioid receptor, A118G) and COMT (enzyme that degrades catecholamines such as norepinephrine, G1947A). Pain intensity (visual analogue scale, VAS), morphine equivalent daily dose (MEDD), adverse events (AEs) and suspected adverse drug reactions (ADRs) were recorded and analysed by gender. The Ethics Committee approved the study and data were analysed with R 3.6.0 software. A total of 748 patients were recruited in the study (67% female, VAS 62 ± 29 mm, MEDD 119 ± 114 mg/day) reporting a median of 6 (3.5-9) AEs/patient. Women presented more nausea, headaches, insomnia, loss of appetite, weight change, depression and dizziness than men. Analysis by genotype demonstrated that PGx influenced the prevalence of vomiting and depression in men, dizziness in women and sexual dysfunction in both. Physicians notified 150 ADRs mostly in females (79%) related to nervous system disorders. PGx applied to a pharmacovigilance recording system provides important information to achieve a better knowledge about AEs in CNCP pharmacological therapy. OPRM1 and COMT polymorphisms were associated with AEs in CNCP patients that differed according to gender.

Internal health locus of control as a predictor of pain reduction in multidisciplinary inpatient treatment for chronic pain: a retrospective study

Purpose

Chronic pain is a major health concern and its treatment requires physiological as well as psychological interventions. This study investigates the predictive value of health locus of control (HLOC) in pain intensity in chronic pain patients in an inpatient treatment setting.

Patients and methods

Data of 225 patients with a chronic pain condition were collected in a psychosomatic university clinic in Switzerland. Self-report assessment tools were used to measure pain intensity pre- and posttreatment and with a questionnaire dimensions of the HLOC were captured. Using hierarchic linear regression analysis, the predictive value of HLOC was investigated.

Results

A higher internal HLOC at pre-treatment was associated with a greater reduction in pain intensity from pre- to posttreatment (β = -0.151, p<0.05). For social-external and fatalistic-external HLOC no significant effects were observed.

Conclusion

Internal HLOC showed predictive value regarding the reduction in pain intensity in a multidisciplinary inpatient treatment for chronic pain, whereas social-external and fatalistic-external HLOC did not. Early interventions to strengthen internal beliefs of health control may be a promising component in multidisciplinary inpatient treatment for patients with chronic pain.