Three selected placebo-controlled trials examined intrathecal ziconotide for severe refractory pain. Intrathecal delivery and the studied populations are essential context; these are not general-use pain studies.123
Bottom line from this bounded source set
The trials reported greater short-term pain-score improvements than placebo, with neurological and other adverse effects. Differences in trial duration and exposure schedules limit comparisons among studies.123
Reviewed study record
Severe chronic pain: three-week trial
Design
Randomized placebo-controlled study with gradual exposure adjustment over three weeks.1
Population
112 people were assigned ziconotide and 108 placebo.1
Outcomes reported
Mean pain-score improvement was 14.7% versus 7.2%. Reported adverse effects included dizziness, confusion, impaired coordination, abnormal gait and memory impairment.1
Limitations
The short trial cannot establish durable benefit or uncommon harms. Similar discontinuation rates do not remove the neurological safety concerns.1
Reviewed study record
Pain associated with cancer or AIDS
Design
Randomized, double-blind, placebo-controlled trial with a brief initial comparison followed by maintenance or crossover.2
Population
111 adults with severe refractory cancer- or AIDS-associated pain were enrolled.2
Outcomes reported
Mean pain-intensity improvement during the initial comparison was 53.1% versus 18.1%.2
Limitations
Brief comparison, crossover and a highly selected population limit long-term interpretation. The abstract does not give a sufficiently detailed adverse-event account.2
Reviewed study record
Severe nonmalignant pain
Design
Randomized, double-blind, placebo-controlled inpatient trial over six days.3
Population
169 participants received ziconotide and 86 placebo.3
Outcomes reported
Mean pain-score reduction was 31.2% versus 6.0%. Adverse events prompted a protocol exposure reduction and included gait and visual disturbances, dizziness, nausea and urinary retention.3
Limitations
Rapid exposure adjustment contributed to substantial adverse effects. The short historical protocol is study context, not a treatment recommendation.3
No registered Crossref update in the reviewed snapshotChecked September 15, 2026 for DOI 10.1016/j.jpainsymman.2005.10.003. This bounded result is not proof that the publication has never been corrected or retracted. Open the pinned Crossref work endpoint ↗
No registered Crossref update in the reviewed snapshotChecked September 15, 2026 for DOI 10.1001/jama.291.1.63. This bounded result is not proof that the publication has never been corrected or retracted. Open the pinned Crossref work endpoint ↗
No registered Crossref update in the reviewed snapshotChecked September 15, 2026 for DOI 10.1111/j.1525-1403.2006.00055.x. This bounded result is not proof that the publication has never been corrected or retracted. Open the pinned Crossref work endpoint ↗