Prescrire international
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Prescrire international · Oct 2008
Ziconotide: new drug. Limited analgesic efficacy, too many adverse effects.
(1) When oral morphine does not relieve severe pain and when there is no specific treatment for the underlying cause, the first option is to try subcutaneous or intravenous administration. If this standard treatment fails or is poorly tolerated, intrathecal injection is usually preferred as the direct route to the central nervous system. However, one-quarter to one-half of patients still do not achieve adequate pain relief, and adverse effects are relatively frequent; (2) Ziconotide is not an opiate and is not related to the usual classes of drugs that interfere with nervous transmission in the posterior horn of the spinal cord. ⋯ Some patients might experience a paradoxical increase in pain with ziconotide; (8) In practice, the efficacy of ziconotide in relieving neurogenic pain remains to be established. In cancer pain, the available evidence showing that ziconotide is effective after opiate failure is too weak in view of the potential risks. It is better to re-examine and, if possible, correct the reasons for opiate treatment failure rather than prescribe ziconotide.