Use of opioids in patients with cancer with hepatic impairment-a systematic review.

Morphine is the preferred opioid in hepatic impairment owing to clinical experience and pharmacokinetics. This review, however, found little clinical evidence to support this. Dose adjustments of morphine and the oxycodone formulations reviewed remain necessary in the absence of quality evidence. Overall, the quality of existing evidence on opioid treatments in cancer pain and hepatic impairment is low and there remains a need for high-quality clinical studies examining this.