Zain Ekachaeryanti, Sugimoto Atsunori, Egawa Jun, Someya Toshiyuki
Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Department of Psychiatry, Faculty of Medicine, Mulawarman University, Samarinda, Indonesia.
Front Psychiatry. 2023 Mar 10;14:1091399. doi: 10.3389/fpsyt.2023.1091399. eCollection 2023.
Chronic pain remains a health problem that is difficult to treat adequately. Its unknown cause and complex comorbidity with other illnesses, including mental disorders, amplify the severity of symptoms, which consequently decreases the quality of life of patients long term. In our clinical practice, we coincidentally found evidence that methylphenidate (MPH) effectively managed chronic pain in an adult patient with attention deficit hyperactivity disorder (ADHD). The effectiveness of MPH in the treatment of ADHD is well-established; however, its utility in treating pain remains unclear.
We present a rare case of a 43-year-old male patient with 15 years of chronic idiopathic pain symptoms that did not adequately respond to standard pain management, such as acetaminophen, non-opioid analgesics, and muscle relaxers. Pain also persisted after treatments with antidepressants and an epidural block. Furthermore, symptoms worsened following several sessions of modified electroconvulsive therapy. After a thorough assessment at our child and adolescent psychiatric outpatient clinic, we confirmed a diagnosis of adult ADHD with a predominantly inattentive type. Considering this newly established diagnosis, we prescribed osmotic-release oral system (OROS) methylphenidate. Within 1 month of treatment at a dose of 18 mg/day of OROS-MPH, the patient's chronic pain unexpectedly improved dramatically, and the patient no longer experienced pain symptoms. The dosage of OROS-MPH was titrated monthly, reaching 72 mg/day as a maintenance dose, and ADHD symptoms improved after 4 months of treatment. The patient was followed up regularly for 7 years during his OROS-MPH treatment. No adverse effects were reported, including stimulant addiction. He was stable overall and functioned well in his daily activities. His pain never recurred.
This case report suggests that MPH may be potentially effective in treating chronic pain. Further studies are needed to confirm whether MPH improved chronic pain simultaneously with or separately from the improvement in ADHD. Moreover, elucidating the anatomical sites and molecular pharmacological mechanisms related to the action of MPH in pain modulation and perception is essential. Such sites include the descending dopaminergic pain pathway and higher cortical areas. Furthering our understanding may reinforce the justification for treating chronic pain using MPH.
慢性疼痛仍然是一个难以得到充分治疗的健康问题。其病因不明，且与包括精神障碍在内的其他疾病存在复杂的共病关系，这加剧了症状的严重程度，从而长期降低了患者的生活质量。在我们的临床实践中，我们偶然发现证据表明，哌甲酯（MPH）能有效治疗一名患有注意力缺陷多动障碍（ADHD）的成年患者的慢性疼痛。MPH治疗ADHD的有效性已得到充分证实；然而，其在治疗疼痛方面的效用仍不明确。
我们报告一例罕见病例，一名43岁男性患者，有15年慢性特发性疼痛症状，对标准疼痛管理措施，如对乙酰氨基酚、非阿片类镇痛药和肌肉松弛剂反应不佳。在使用抗抑郁药和硬膜外阻滞治疗后疼痛仍持续。此外，经过几次改良电休克治疗后症状恶化。在我们的儿童和青少年精神科门诊进行全面评估后，我们确诊该患者为以注意力不集中为主型的成人ADHD。考虑到这一新确诊的疾病，我们开具了渗透泵控释口服系统（OROS）哌甲酯。在以每天18毫克的剂量使用OROS-MPH治疗1个月内, 患者的慢性疼痛意外地显著改善，且不再经历疼痛症状。OROS-MPH的剂量每月滴定，维持剂量达到每天72毫克，治疗4个月后ADHD症状得到改善。在其接受OROS-MPH治疗期间，该患者接受了7年的定期随访。未报告包括兴奋剂成瘾在内的不良反应。他总体稳定，日常活动功能良好。他的疼痛从未复发。
本病例报告表明，MPH可能对治疗慢性疼痛有潜在疗效。需要进一步研究以确认MPH是与ADHD的改善同时还是分别改善慢性疼痛。此外，阐明与MPH在疼痛调节和感知中的作用相关的解剖部位和分子药理机制至关重要。这些部位包括下行多巴胺能疼痛通路和更高皮层区域。深化我们的理解可能会加强使用MPH治疗慢性疼痛的合理性。
