Dipyrone (metamizole) is one of the most widely used non-opioid analgesics for the treatment of cancer pain.

Because evidence-based recommendations are not yet available, a systematic review was conducted for the German Guideline Program in Oncology to provide recommendations for the use of dipyrone in cancer pain.

First, a systematic review for clinical trials assessing dipyrone in adult patients with cancer pain was conducted. Endpoints were pain intensity, opioid-sparing effects, safety, and quality of life.

The search was performed in MedLine, Embase (via Ovid), and the Cochrane Library (1948–2013) and additional hand search was conducted. Finally, recommendations were developed and agreed in a formal structured consensus process by 53 representatives of scientific medical societies and 49 experts.

Of 177 retrieved studies, 4 could be included (3 randomized controlled trials and 1 cohort study, n = 252 patients): dipyrone significantly decreased pain intensity compared to placebo, even if low doses (1.5–2 g/day) were used. Higher doses (3 x 2 g/day) were more effective than low doses (3 x 1 g/day), but equally effective as 60 mg oral morphine/day. Pain reduction of dipyrone and non-steroidal anti-inflammatory drugs did not differ significantly. Compared to placebo, non-steroidal anti-inflammatory drugs, and morphine, the incidence of adverse effects was not increased.

Dipyrone can be recommended for the treatment of cancer pain as an alternative to other non-opioids either alone or in combination with opioids. It can be preferred over non-steroidal anti-inflammatory drugs due to the presumably favorable side effect profile in long-term use, but comparative studies are not available for long-term use.