High opioid dose escalation to 100 and 200 mg per day in patients with long term opioid therapy: Sex difference

• Main Authors: Zin, Che Suraya, Taufek, Nor Hidayah, Alias, Nor Elina, Meor Ahmad, Mazlila
• Format: Conference or Workshop Item
• Language: English; English
• Published: 2019
• Subjects: RM147 Administration of Drugs and Other Therapeutic Agents
• Online Access: http://irep.iium.edu.my/71731/1/190420_aseaps_irep_docx.pdf; http://irep.iium.edu.my/71731/2/190320-Poster_aseap_csz.pdf; http://irep.iium.edu.my/71731/; http://www.aseaps2019.com/eposter_view.php?catID=OT&fileName=ABST031_OT_OT03.pdf

Background It was reported that the risk of opioid overdose death increased with increasing opioid dose and little is known whether sex difference influences the risk of opioid dose escalation or overdose. Objective This study examined the relationship between sex difference and opioid dose escalation in patients with long term opioid therapy. Setting and participants This retrospective cohort study was conducted at tertiary hospital settings in Malaysia using electronic prescription records. Patients with long term opioid therapy of ≥90 days of opioid prescriptions and aged ≥18 years old with at least one opioid prescription (buprenorphine, morphine, oxycodone, fentanyl, dihydrocodeine and tramadol) between 1st January 2011, and 31st December 2016 were included. Follow-up was started from patients’ first opioid prescription until discontinuation of therapy, death from any cause or the end of the study period, with no interval of 120 days between the successive prescriptions. The risk of high opioid dose escalation to ≥100 mg/day and ≥200 mg/day relative to men and women was measured using a Cox proportional hazard model which was controlled for the effect of age. The adjusted hazard ratios and 95% Confidence Intervals (CIs) were used to summarize the risk of dose escalation using Stata v15.1 Results A total of 4688 patients with long term opioid therapy were identified. Of these, 248 (5.29%) escalated to high opioid doses of ≥100mg/day and 69 (1.47%) escalated to ≥200mg/day. The median time at risk to reach ≥100 and ≥200 mg/day was 126 days for men and 162 days for women. After adjusted for age, men were more likely than women to be escalated to high-dose opioid therapy of ≥100 mg/day (adjusted hazard ratio 2.32; 95% CI 1.79 to 3.00, p<0.0001) and ≥200 mg/day (adjusted hazard ratio 6.10; 95% CI 3.39 to 10.98, p<0.0001). Conclusions The risk of opioid dose escalation was different between men and women in which men are at higher risk than women for escalation to high-dose opioid therapy. Further research is necessary to understand the factors contributing to the observed differences and its association with clinical outcomes.