吗啡
医学
安慰剂
麻醉
神经病理性疼痛
类阿片
止痛药
慢性疼痛
养生
生理盐水
坐骨神经
药理学
内科学
物理疗法
受体
替代医学
病理
作者
Damien C. Boorman,Kevin A. Keay
出处
期刊:Behavioural Pharmacology
[Ovid Technologies (Wolters Kluwer)]
日期:2021-07-26
卷期号:32 (6): 479-486
被引量:5
标识
DOI:10.1097/fbp.0000000000000642
摘要
Many people with chronic pain escalate their opioid dosage to counteract tolerance effects. A treatment regimen consisting of placebos admixed with opioids has been suggested as a possible therapeutic option that could reduce the harm of long-term opioid use. However, the analgesic efficacy of such a regimen requires further investigation before widespread adoption. We have recently reported that a 4-day pharmacological conditioning procedure, which paired morphine (6 mg/kg) with contextual cues, elicited placebo analgesia in subpopulations of male (35%) and female (25%) rats with sciatic nerve chronic constriction injury (CCI). Here, we investigated how an escalating morphine dosage during conditioning affects the incidence and strength of placebo analgesia. Forty-four male, Sprague-Dawley rats received CCI. Thirty-eight (86%) rats developed strong cold allodynia by day 6 post-surgery, as measured by hind paw withdrawal (HPW) behaviour on a 5°C cold plate (120 s). In this experiment, pharmacological conditioning consisted of an escalating morphine dose over 4 days (8/9/10/12 mg/kg). This dosing regimen produced strong reductions in HPW behaviour and counteracted the effects of morphine tolerance during conditioning. However, none of the rats given the placebo treatment (n = 12) demonstrated reductions in HPW behaviour when morphine was substituted for saline (i.e. placebo analgesia), but instead showed a strong behavioural response (rearing). These results demonstrate that a high, escalating dose of morphine failed to produce conditioned placebo analgesia in rats with CCI. It is possible that admixing placebos with opioids may be similarly ineffective in chronic pain patients when the opioids regimen is high or escalating.
科研通智能强力驱动
Strongly Powered by AbleSci AI