SIDE-EFFECTS OF INTRATHECAL AND EPIDURAL OPIOIDS

The purpose of this article is to review the literature on the side ef fects of intrathecal and epidural opioids. English-language articles w ere identified through a MEDLINE search and through review of the bibl iographies of identified articles. With the increasing utilization of intrathecal and epidural opioids in humans during the 1980s, a wide va riety of clinically relevant side effects have been reported. The four classic side effects are pruritus, nausea and vomiting, urinary reten tion, and respiratory depression. Numerous other side effects have als o been described. Most side effects are dose-dependent and may be more common if the opioid is administered intrathecally. Side effects are less common in patients chronically exposed to either intrathecal, epi dural, or systemic opioids. Some side effects are mediated via interac tion with specific opioid receptors while others are not. It is conclu ded that the introduction of intrathecal and epidural opioids marks on e of the most important breakthroughs in pain management in the last t wo decades. However, a wide variety of clinically relevant non-nocicep tive side effects may occur. All physicians utilizing intrathecal and epidural opioids must be aware of these side effects, for while most a re minor, others are potentially lethal.