[WHO step II-clinical reality or a didactic instrument?]

In 1986 the World Health Organisation (WHO) proposed an analgesic ladder for the effective therapy of cancer pain. The three standard analgesics making up this ladder are aspirin (non-opioid), codeine (weak opioid) and morphine (strong opioid). Adjuvant drugs may be added at any level. However, before 1986 step II analgesics (weak opioids) had never been tested in cancer pain relief.

This report presents a computer-assisted Medline (US National Library of Medicine) literature search restricted to the years 1986-1994, which was conducted to test the validity of the WHO guidelines, and in particular that of step II.

We found seven retrospective studies and one prospective study on cancer pain treatment according to the proposed WHO guidelines that had been published since 1986. Every publication decribed the use of all three steps of the analgesic ladder. We found no prospective controlled trials demonstrating the efficacy and safety of WHO step II in particular.

The use of the WHO guidelines "by mouth, by the clock and by the ladder" is now the mainstay of cancer pain management. Because of the guidelines' simplicity they found general acceptance and helped to establish an international pain therapy standard for worldwide use. Nevertheless, there is no scientific validation of WHO step II. In the absence of prospective controlled randomized trials additional longterm results are necessary. We need more data on the use of WHO step II and an update of the published guidelines taking account of modern sustained-release drugs. Up to now, step II of the WHO guidelines for cancer pain is not a clinical reality but at best a didactic instrument.