Differential Experience of Interdose Withdrawal During Long-Term Opioid Therapy and its Association With Patient and Treatment Characteristics: A Latent Class Analysis in Chronic Pain Population.

Opioid withdrawal is characterized by a set of physical and psychological symptoms that depend on both opioid and patient specific characteristics. The present study aims to identify different latent classes of chronic pain patients according to the type of opioid withdrawal symptoms experienced, and to analyze the relationships between the classes and demographic, opioid therapy, psychological and substance use variables. This cross-sectional descriptive study included 391 chronic pain patients on long-term opioid therapy. A Latent Class Analysis (LCA) identified 3 classes (BIC = 7051.89, entropy = .87, LRTs P < .01). The mild withdrawal class showed low probabilities of presenting physical and psychological symptoms, the moderate withdrawal class was characterized by experiencing psychological symptoms, and the severe withdrawal class stood out for high probabilities of presenting both types of symptoms. The classes differed from each other, with higher rates of moderate-severe POUD, opioid misuse, anxiety, depression, and greater pain intensity and interference in more severe withdrawal classes (P < .05). The multinomial logistic regression showed that moderate-severe POUD and anxiety were the strongest variables related to moderate (OR = 3.34, OR = 2.58) and severe withdrawal classes (OR = 4.26, OR = 5.15). Considering that POUD and anxiety were strongly related to a more severe withdrawal syndrome, the inclusion of psychological interventions in pain management seems critical in this population. PERSPECTIVE: Although interdose opioid withdrawal is common in chronic pain patients, this study shows 3 different patterns in its experience (mild, moderate, and severe withdrawal). A more severe withdrawal may result in reduced effectiveness of opioids in relieving pain and increased negative consequences, such as higher risk of POUD. Findings that could help improve chronic pain management.