Three open-label studies evaluated multiple-dosing ketamine. aan het Rot enrolled 10 participants from an earlier trial of the effects #PF-04691502 clinical trial randurls[1|1|,|CHEM1|]# of ketamine on suicidality [Price et al. 2009] who had an initial depressive symptom severity ≥32 on the Inventory for Depressive Symptoms (IDS-C30) and who had demonstrated a clinical response to this single ketamine infusion without significant side effects [aan het Rot et al. 2010]. Participants were given 6 infusions over 12 days: 90% of participants responded to the first infusion, and by the end of the trial 100% met response criteria and 88.89% met remission criteria. The same research group
Inhibitors,research,lifescience,medical undertook a larger study [Murrough et al. 2013] of 24 individuals, including the 10 participants in the previous work, who, after a wash-out period from their antidepressants, each received thrice weekly injections of ketamine over 12 days. There was a large, statistically significant (p < 0.01) decrease in MADRS scores 2 hours after the initial infusion (mean Inhibitors,research,lifescience,medical decrease 18.9, standard deviation [SD] 6.6). A total of 21 participants completed the full 6-infusion
schedule and the response Inhibitors,research,lifescience,medical rate at the study’s conclusion was 70.8% (17 of 24). Response to ketamine 4 hours after the initial infusion was strongly associated with the response by the study’s end, with 94% of those responding doing so 4 hours after the first infusion. A more recent study conducted by Rasmussen and colleagues administered 10 participants in a MDE (BPAD II/MDD) with up to 4 ketamine infusions at 0.5 mg/kg over 100 minutes [Rasmussen et al. 2013]. A total of 80% of the Inhibitors,research,lifescience,medical participants demonstrated response to ketamine, defined as at least a 50% reduction in MADRS scores, and furthermore 50% met remission, defined as a MADRS score of 9 and below. Of the 5 participants who met remission, 2 still
met remission criteria at the 4-week follow up. Rasmussen and colleagues further documented the effect of ketamine Inhibitors,research,lifescience,medical on suicidal ideation, reporting significant improvements in the Scale for Suicide Ideation (SSI; p = 0.007) and the Suicide Status Form (SSF; p = 0.026). In addition, this study reported a significant correlation between SSI/SSF scores and MADRS (p < 0.01), suggesting the observed decrease in suicidality occurred in unison with that of depression scores. Two studies, both single-dosing, looked primarily at the Ketanserin effects of ketamine on suicidal ideation. Price and colleagues tested changes in 26 patients with TRD [Price et al. 2009]: 24 hours post-infusion the average reduction in the six-point MADRS Suicidality Item (SI) subscale score across all participants was 2.08 (p < 0.001), with 81% scoring of 0 or 1. Of the 13 patients with clinically significant baseline suicidal ideation (MADRS-SI ≥4) 8 (62%) scored zero or one at the 24-hour follow up. Similarly positive results were reported by DiazGranados and colleagues [DiazGranados et al. 2010a].