Objective: To evaluate the effect of the use of benzodiazepines on prescription of opioids 4-7 years later in patients with noncancer pain.
Design: A cohort of 7,991 men and 9,083 women aged 40, 45 and 60 years who reported no use of opioids in health surveys in 2000-2001 was linked to the nationwide Norwegian Prescription Database, and their prescriptions of opioids during 2004-2007 were analyzed. Moderate-high prescription frequency of opioids was defined as at least 12 prescriptions during the period January 2004-December 2007.
Results: The unadjusted odds ratio for moderate-high prescription frequency of opioids for individuals who had previously used benzodiazepines was 7.7 (95% confidence interval 5.6-10.5) as compared with previous nonusers. After adjustment for musculoskeletal pain, alcohol, smoking habits, and socioeconomic variables, the odds ratio was lowered to 3.1 (2.1-4.6). The analysis of the effect of benzodiazepines and chronic pain individually and in combination suggest that use of benzodiazepines is an even stronger predictor of later opioid use than self-reported chronic pain.
Conclusions: Our study suggests that earlier use of benzodiazepines may predict repeated use of opioids. Before starting pain treatment with opioids, clinicians should take into consideration the possibility of substance abuse and mental health disorders. A central issue when prescribing opioids for chronic noncancer pain is to balance the risk of problematic use of these drugs with the benefits of pain relief.