Prescrire international
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Prescrire international · Dec 2008
Clinical trials registries: towards improved access to therapeutic data.
(1) On July 1, 2005, several leading biomedical journals decided to publish only the results of clinical trials that had been listed in approved registries; (2) More and more clinical trials are now being recorded in a variety of national and international registries by an increasing number of private and public institutions; (3) The international network of WHO-approved registries, operational since 2007, provides access to more than 60 000 trials (in April 2008), but there is still no single comprehensive international registry of clinical trials; (4) The US registry (ClinicalTrials.gov) is publicly accessible, but the public does not have online access to the European registry (EudraCT); (5) These registries would be more useful if registration were transparent and mandatory in all countries where clinical trials are conducted; (6) Patients who agree to participate in a clinical trial should first verify that the study is listed in a WHO-approved registry and that the authors have committed to publish the results.
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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.