The duration and course of opioid therapy in patients with chronic non-malignant pain.

BACKGROUND: Prescription databases provide the opportunity for investigating opioid treatment and co-medication within large populations. So far, few studies have investigated the duration of opioid therapy, and large differences in discontinuation rates have been reported. METHODS: Data from the Norwegian Prescription Database were used to follow the study population of all adult persistent opioid users with non-malignant pain in Norway in 2005 (n = 44,867) for 6 years. Persistent opioid use was defined as being dispensed ≥ 180 defined daily doses (DDD) or 4500 mg oral morphine equivalents (OMEQ) during a 365-day period. The study population was stratified according to previous opioid use into new persistent opioid users, without previous persistent opioid use, and previous low-dose or previous high-dose persistent opioid users, having earlier persistent opioid use and received less or more than 120 mg OMEQ/day in 2005, respectively. RESULTS: Twenty-seven percent of new, 59% of previous low-dose, and 55% of previous high-dose users met the criteria of persistent use of opioids each year. Exactly, 22%, 11%, and 3% increased their cumulative yearly opioid dose by 200% or more during the study period. With 80% still being regular users of either drugs, 6 years later, long-term persistent opioid users were more likely to continue concomitant use of benzodiazepines or z-hypnotics than other users, CONCLUSION: The findings confirm high discontinuation rates in patients receiving opioids for chronic non-malignant pain. However, a clinically significant number of patients increase their doses over 6 years and many patients combine long-term opioid treatment with benzodiazepines and z-hypnotics.

Co-morbidity in persistent opioid users with chronic non-malignant pain in Norway.

BACKGROUND: In patients with chronic non-malignant pain (CNMP), co-morbid physical or mental health disorders are common and may have a negative impact on health-related quality of life and treatment outcomes. The purpose of this study was to examine the occurrence of chronic psychiatric and somatic diseases in persistent opioid users with CNMP compared with the general population in Norway. METHODS: In this cross-sectional study, prescription patterns of dispensed opioids were used to identify a study population of persistent opioid users with CNMP from the general population. Reimbursed prescriptions marked with diagnostic codes were used to identify the occurrence of 21 somatic and 3 psychiatric diseases for a 1-year period in the Norwegian Prescription Database. Occurrence of disease in persistent opioid users was compared to an age- and gender-specific population of all Norwegian residents aged 18-79 years in 2009. Standardized morbidity ratios (SMRs) for each disease were calculated. RESULTS: Eighty-five percent of the persistent opioid user population had at least one co-morbid disease compared with 45% of the general population. Forty-two percent had three or more co-morbidities. SMRs in both men and women were generally increased except for dementia, glaucoma and renal disease, indicating a higher occurrence of disease in persistent opioid users. CONCLUSIONS: A higher occurrence of both somatic and psychiatric co-morbidities in disease stages warranting pharmacological treatment was found in persistent opioid users with CNMP compared with the general population of Norway.

Concomitant medication among persistent opioid users with chronic non-malignant pain.

BACKGROUND: Recent guidelines for opioid treatment of chronic non-malignant pain discourage co-medication with benzodiazepines and benzodiazepine-related hypnotics, whereas co-medication with non-opioid analgesics and co-analgesics may offer a beneficial opioid sparing effect, and is recommended. The aim of this study was to describe 1-year periodic prevalence of co-medication with benzodiazepines, benzodiazepine-related hypnotics, non-opioid analgesics, co-analgesics and antidepressants in persistent opioid users with chronic non-malignant pain. METHODS: The study is based on data from the Norwegian Prescription Database, covering all drugs dispensed to outpatients in 2008. Concomitant medication levels were compared between users in two definitions of persistent opioid use, all Norwegian adults dispensed opioids in 2008 and the Norwegian background population. RESULTS: Of the Norwegian adult population studied, 1.2% met the criteria of persistent opioid use based on prescription pattern and prescription level. Sixty percent of persistent opioid users were dispensed a benzodiazepine or benzodiazepine-related hypnotic in amounts indicating regular use, with 15% dispensed a high amount of both classes. Sixty-two percent of persistent opioid users were dispensed one or more non-opioid analgesics, 47% an antidepressant and 33% were dispensed an antiepileptic drug. CONCLUSION: Approximately 60% of persistent opioid users also receive benzodiazepines or benzodiazepine-related hypnotics in amounts indicating regular use. This is in conflict with recent guidelines for the treatment of chronic non-malignant pain and may indicate that these users are at an increased risk of developing problematic opioid use.

Choosing the unit of measurement counts: the use of oral morphine equivalents in studies of opioid consumption is a useful addition to defined daily doses.

AIM: Defined daily dose (DDD) is the most common measurement unit used in drug consumption studies. The DDD for opioids may not reflect their relative clinical potencies. The aim of this study was to explore whether opioid consumption data may be interpreted differently when adding oral morphine equivalent (OMEQ) dose as a measurement unit compared with using DDD. METHODS: The equianalgesic ratio of each opioid relative to morphine was tabulated. Data on opioid consumption expressed in DDD were converted to OMEQs using the equianalgesic ratios. The opioid consumption was compared in three different study settings: clinical data from an opioid switching study, trends within one country and a comparison between countries. RESULTS: Using DDD, the opioid consumption in Norway between 2004-2008 increased of 6.7%, while the increase was 23.6% using OMEQ. While DDD/1000 inhabitants/day showed that Sweden had the highest consumption of opioids among the Nordic countries, OMEQ/1000 inhabitants/day showed that Denmark had the highest consumption. In the switching study DDD indicated a reduction in analgesic dosing and OMEQ an increase when switching from WHO step II to III. CONCLUSION: OMEQ reflects clinical dosing better than DDD, and can give additional insight into opioid consumption when combined with DDD. Using OMEQ can also lead to different conclusions in opioid consumption studies compared with using DDD alone.

Influence of the cation on the side-effects of urographic contrast media.

The incidence of side-effects produced by meglumine diatrizoate and meglumine-, meglumine-calcium-, and sodium-calcium-magnesium metrizoate, was compared in 800 urographies. Patients older than 60 years seem to have less side-effects than younger patients. The incidence of sensation of warmth seems to be higher in patients who have had previous urographies, compared to those who are examined for the first time. The incidence of this effect is higher for the sodium-calcium-magnesium salt of metrizoate, than for other salts of metrizoate.