悪液質に対する酢酸メゲステロール：コクラン

悪液質に対する酢酸メゲステロールのコクランレビューを紹介します。

Ruiz Garcia V, López-Briz E, Carbonell Sanchis R, Gonzalvez Perales JL, Bort-Marti S. Megestrol acetate for treatment of anorexia-cachexia syndrome. Cochrane Database Syst Rev. 2013 Mar 28;3:CD004310. doi: 10.1002/14651858.CD004310.pub3.

前回2005年のバージョンからアップデートされたものです。結果ですが、エイズやがんによる悪液質に対する酢酸メゲステロール投与で、プラセボと比較すると食欲増進や体重増加が得られました。一方、他の薬との比較では有意な改善は認めませんでした。

投与量に関しては量が多いほうが体重増加が多いです。QOLはプラセボとの比較では改善しましたが、他の薬との比較では有意差を認めませんでした。酢酸メゲステロールの副作用として、浮腫、血栓塞栓症、死亡が有意に増加しました。

以上より、エイズやがんによる悪液質に対する酢酸メゲステロール投与で、食欲改善とわずかな体重増加を認めるという結論です。ただし、緩和ケアを受けている患者であっても、リスクについて十分に伝えることが必要です。

コクランレビューで有効というのは意味がありますが、体重増加の一因は浮腫かもしれません。また死亡が有意に増加するようでは、食欲改善や体重増加より問題が大きいです。日本では使用できない薬剤ですが、使用できたとしても適応は少ない気がします。

Abstract

BACKGROUND:

This is an updated version of a previously published review in The Cochrane Library (2005, Issue 2) on 'Megestrol acetate for the treatment of anorexia-cachexia syndrome'. Megestrol acetate (MA) is currently used to improve appetite and to increase weight in cancer-associated anorexia. In 1993, MA was approved by the US Food and Drug Administration for the treatment of anorexia, cachexia or unexplained weight loss in patients with AIDS. The mechanism by which MA increases appetite is unknown and its effectiveness for anorexia and cachexia in neoplastic and AIDS (acquired immunodeficiency syndrome) patients is under investigation.

OBJECTIVES:

To evaluate the efficacy, effectiveness and safety of MA in palliating anorexia-cachexia syndrome in patients with cancer, AIDS and other underlying pathologies.

SEARCH METHODS:

We sought studies through an extensive search of electronic databases, journals, reference lists, contact with investigators and other search strategies outlined in the methods. The most recent search for this update was carried out in May 2012.

SELECTION CRITERIA:

Studies were included in the review if they assessed MA compared to placebo or other drug treatments in randomised controlled trials of patients with a clinical diagnosis of anorexia-cachexia syndrome related to cancer, AIDS or any other underlying pathology.

DATA COLLECTION AND ANALYSIS:

Two independent review authors conducted data extraction and evaluated methodological quality. We performed quantitative analyses using appetite and quality of life as a dichotomous variable, and analysed weight gain as continuous and dichotomous variables.

MAIN RESULTS:

We included 35 trials in this update, the same number but not the same trials as in the previous version of the review. The trials comprised 3963 patients for effectiveness and 3180 for safety. Sixteen trials compared MA at different doses with placebo, seven trials compared different doses of MA with other drug treatments and 10 trials compared different doses of MA. Meta-analysis showed a benefit of MA compared with placebo, particularly with regard to appetite improvement and weight gain in cancer, AIDS and other underlying conditions, and lack of benefit in the same patients when MA was compared to other drugs. There was insufficient information to define the optimal dose of MA, but higher doses were more related to weight improvement than lower doses. Quality of life improvement in patients was seen only when comparing MA versus placebo but not other drugs in both subcategories: cancer and AIDS. Oedema, thromboembolic phenomena and deaths were more frequent in the patients treated with MA. More than 40 side effects were studied.

AUTHORS' CONCLUSIONS:

This review shows that MA improves appetite and is associated with slight weight gain in cancer, AIDS and in patients with other underlying pathology. Despite the fact that these patients are receiving palliative care they should be informed of the risks involved in taking MA.