Zahari Zalina, Lee Chee Siong, Ibrahim Muslih Abdulkarim, Musa Nurfadhlina, Mohd Yasin Mohd Azhar, Lee Yeong Yeh, Tan Soo Choon, Mohamad Nasir, Ismail Rusli
Department of Pharmacy, Hospital Universiti Sains Malaysia, Kelantan, Malaysia. Pharmacogenetics and Novel Therapeutics Cluster, Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM), Kelantan, Malaysia.
J Pharm Pharm Sci. 2016;19(1):127-36. doi: 10.18433/J3NS49.
This study compared pain sensitivity among opioid dependent patients on methadone maintenance therapy (MMT) and opioid naive subjects.
The three hundred participants comprised 152 opioid naive subjects and 148 opioid dependent patients. Opioid naive subjects had not taken any opioids including morphine and methadone to their best knowledge and were presumed so after two consecutive negative urine screenings for drugs. All opioid dependent patients were stabilized in treatment, defined as having been enrolled in the program for more than one month with no change of methadone dosage over the past one month. Excluded from the study were individuals with chronic or ongoing acute pain and individuals with a history of analgesics ingestion within 3 d before the cold pressor test (CPT). Pain tolerance to CPT was evaluated at 0 h, and at 2, 4, 8, 12, and 24 h post-methadone dose.
Patients exhibited a significantly shorter mean pain tolerance time of 34.17 s (95% CI 24.86, 43.49) versus 61.36 (52.23, 70.48) [p < 0.001] compared with opioid naive subjects. Time-dependent mean pain tolerance was also significantly different when naive subjects were compared to patients (p = 0.016).
This study revealed hyperalgesia amongst patients on MMT, as manifested by their quicker hand withdrawal. The complaints of pain in this population should not be underestimated and the pain should be evaluated seriously and managed aggressively.
本研究比较了接受美沙酮维持治疗（MMT）的阿片类药物依赖患者与未使用过阿片类药物的受试者之间的疼痛敏感性。
300名参与者包括152名未使用过阿片类药物的受试者和148名阿片类药物依赖患者。未使用过阿片类药物的受试者据其所知未服用过任何阿片类药物，包括吗啡和美沙酮，且在连续两次尿液药物筛查呈阴性后被认定如此。所有阿片类药物依赖患者的治疗均已稳定，定义为已参加该项目超过1个月，且在过去1个月内美沙酮剂量未改变。排除有慢性或持续性急性疼痛的个体以及在冷加压试验（CPT）前3天内有镇痛药摄入史的个体。在美沙酮给药后0小时、2小时、4小时、8小时、12小时和24小时评估对CPT的疼痛耐受性。
与未使用过阿片类药物的受试者相比，患者的平均疼痛耐受时间显著缩短，分别为34.17秒（95%可信区间24.86, 43.49）和61.36秒（52.23, 70.48）[p < 0.001]。将未使用过阿片类药物的受试者与患者进行比较时，时间依赖性平均疼痛耐受性也有显著差异（p = 0.016）。
本研究揭示了接受MMT的患者存在痛觉过敏，表现为他们更快地将手撤回。不应低估该人群的疼痛主诉，应认真评估并积极处理疼痛。
