Ketamine as an adjuvant to opioids for cancer pain

  • Review
  • Intervention


  • Rae F Bell,

    Corresponding author
    1. Haukeland University Hospital/University of Bergen, Institute of Surgical Sciences/Regional Centre of Excellence in Palliative Care, Bergen, Norway
    • Rae F Bell, Institute of Surgical Sciences/Regional Centre of Excellence in Palliative Care, Haukeland University Hospital/University of Bergen, Bergen, N-5021, Norway.

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  • Christopher Eccleston,

    1. Centre for Pain Research, University of Bath, Cochrane Pain, Palliative and Supportive Care Review Group, Bath, UK
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  • Eija A Kalso

    1. Helsinki University Central Hospital, Department of Anaesthesia and Intensive Care Medicine, Helsinki, Finland
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This is an update of the original review published in Issue 1, 2003. Ketamine is a commonly used anaesthetic agent, and in subanaesthetic doses is also given as an adjuvant to opioids for the treatment of cancer pain, particularly when opioids alone prove to be ineffective. Ketamine is known to have hallucinogenic side effects.


To determine the effectiveness and adverse effects of ketamine as an adjuvant to opioids in the treatment of cancer pain.

Search methods

Studies were identified from MEDLINE (1966 to 2002), EMBASE (1980 to 2002), CancerLit (1966 to 2002), T he Cochrane Library (Issue 1, 2001); by handsearching reference lists from review articles, trials, and chapters from standard textbooks on pain and palliative care. The manufacturer of ketamine (Pfizer Parke-Davis) provided search results from their in-house database, PARDLARS.

An improved and updated search of the following was performed in February 2007: Specialized Register of the Cochrane Pain, Palliative and Supportive Care group (PaPas), CENTRAL, MEDLINE & OVID MEDLINE R, EMBASE, PubMed (Limit to cancer subset),The Pfizer Product information database. In addition, the Cochrane database of systematic reviews was searched in April 2007.

Selection criteria

RCTs of adult patients with cancer and pain being treated with an opioid, and receiving either ketamine (any dose and any route of administration) or placebo or an active control.

Data collection and analysis

Two independent review authors identified four RCTs for possible inclusion in the review, and 32 case studies/case series reports. Quality and validity assessment was performed by three independent review authors, and two RCTs were excluded because of inappropriate study design. Patient reported pain intensity and pain relief was assessed using visual analog scales, verbal rating scales or other validated scales, and adverse effects data were collated.

Main results

No new trials were identified by the updated search. Two trials were eligible for inclusion in the original review and both concluded that ketamine improves the effectiveness of morphine in the treatment of cancer pain. However, pooling of the data was not appropriate because of the small total number of patients (30), and the presence of clinical heterogeneity. Some patients experienced hallucinations on both ketamine plus morphine and morphine alone and were treated successfully with diazepam. No other serious adverse effects were reported.

Authors' conclusions

Since the last version of this review no new studies were found. Current evidence is insufficient to assess the benefits and harms of ketamine as an adjuvant to opioids for the relief of cancer pain. More randomized controlled trials are needed.








我們收尋了MEDLINE(1966年至2002年),EMBASE(1980年至2002年),CancerLit(1966年至2002年),The Cochrane Library (Issue 1, 2001);並以手工查閱並摘選標準的教科書中有關疼痛護理和姑息治療之評論文章、試驗之章節參考清單,再從以上資料庫系統所檢索確定的文獻。ketamine製造商(Pfizer ParkeDavis)所提供的結果從他們的公司內部數據庫PARDLARS搜索出來。在2007年2月有更新進的搜索:Specialized Register of the Cochrane Pain,Palliative and Supportive Care group (PaPas), CENTRAL,MEDLINE & OVID MEDLINE R,EMBASE, PubMed(僅限癌症),The Pfizer Product information database。除此之外,還收尋2007年4月the Cochrane database of systematic reviews。











此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。



Plain language summary

Ketamine as an adjuvant to opioids for cancer pain

The benefits and harms of adding ketamine to strong pain-killers such as morphine for the relief of cancer pain are not yet established. Morphine-like drugs (opioids) are frequently prescribed for moderate and severe cancer pain, but in some cases these drugs are not effective. Ketamine, an anaesthetic agent, is used to improve analgesia when opioids alone are ineffective. However, evidence for the effectiveness of this practice is limited. Two small trials suggest that when ketamine is given with morphine it may help to control cancer pain. However, these data are insufficient to assess the effectiveness of ketamine in this setting.