Dose and duration of opioid use in patients with cancer andn non-cancer pain at an outpatient hospital setting in Malaysia: A retrospective cross sectional study

• Main Authors: Zin, Che Suraya, Abdul Rahman, Norny Syafinaz, Ismail, Che Rokiah, Leong, Weng Choy
• Format: Conference or Workshop Item
• Language: English; English
• Published: 2016
• Subjects: RS Pharmacy and materia medica
• Online Access: http://irep.iium.edu.my/52343/1/161017_abstract%20_scan.pdf; http://irep.iium.edu.my/52343/7/52343-web.pdf; http://irep.iium.edu.my/52343/

Aims of investigation: Prescribing of opioid analgesics have tremendously increased over the last few decades and the increase was also associated with increasing incidence of dependence, misuse and overdose related deaths. There is currently limited data available on the patterns of opioid prescribing in Malaysia. The objective of this study was to investigate the patterns of opioid prescribing and characterize the dosing and duration of opioid therapy for the treatment of cancer and non-cancer pain. Methods: This retrospective cross sectional study was conducted at the outpatient pharmacy Hospital Tengku Ampuan Afzan, Kuantan, Malaysia. Opioid prescriptions of dihydrocodeine, fentanyl, morphine and oxycodone issued between January 2013 and December 2014 were examined. Each prescription record contains information of patient demographic, diagnosis, prescription date, drug name and strength, frequency, duration and quantity supply. Outcome measures include the total number of prescriptions and patients, distribution of individual mean daily dose, individual total days covered with opioids in a year, and individual total opioid dose in a year. The measures were calculated and stratified by cancer and non-cancer patients. Descriptive statistics were used in the analysis and all statistical analyses were performed using Stata 13 (Stata Corp LP, Texas, USA). Results: A total of 1015 opioid prescriptions were prescribed for 347 patients during the study period. Forty two percent of patients (n=144/347) were associated with non-cancer diagnosis while 58% (n=203/347) were associated with cancer diagnosis. The predominant age group for patients with non-cancer and cancer was 51-65 years old (31.9%) and 66-80 years old (37%) respectively. Oxycodone (38.0%) was the highest prescribed and the majority was for non-cancer group followed by morphine (27%) which was used more frequently for cancer group. Majority of patients in both non-cancer (74.3%) and cancer (60.4%) groups were receiving mean daily doses of < 50 mg morphine equivalents with the median daily dose of 26 and 35 mg morphine equivalents respectively. The proportion of patients prescribed with a mean daily dose of >100 mg morphine equivalents was lower in the non-cancer group (5.1%). than in the cancer group (14.8%). The proportion of patients with more than 90 days covered with opioid per year (indicator for chronic use) was higher in the non-cancer group (21.8%) than in the cancer group (17.5 %). The median days covered in a year was 37 days in both study groups. Conclusions: The finding from this study showed that 42% of opioid users at an outpatient hospital setting in Malaysia received opioids for non-cancer pain and 21.8% of these users were prescribed opioid for long term. Oxycodone was the highest prescribed and the majority was for non-cancer pain followed by morphine which was used more frequently for cancer pain. Majority of patients in both non-cancer and cancer groups were receiving daily doses of <50 mg morphine equivalents. Future well-designed longitudinal studies are required to evaluate the appropriateness of opioid utilization (over- or under-prescribing ) and to examine the clinical outcomes, relationship between sociodemographic, medical and psychiatric factors and opioid use in patients receiving long term opioid therapy. Declaration: All Authors declare they have no financial support or relationship that may pose conflict of interest.