[Weak opioids]

Abstract

Weak opioids have been used as analgesics in cancer patients with moderate to severe chronic pain. Codeine is one of the weak opioids which is assigned as a representative analgesic of the 2nd ladder-drugs for the treatment of cancer pain by WHO cancer pain relief programme. Analgesic effect of codeine is recognized when it is administered with 20 mg p.o. or more. Clinical ceiling effect of codeine is seemed to be 200-300 mg/day, although it is described as 600 mg/day in some textbooks. Side effects of codeine are same as those of morphine, therefore, drugs for the side effects should be given to the patients simultaneously when codeine is administered.