Actually this is not correct R-Isomer is, as it is clearly less psychomimetic and more relaxing, some psychiatrists at US ketamine clinics are also aware of this.
https://www.researchgate.net/profil..._-ketamine/links/5653168608ae1ef92975af1c.pdf
My source says:
EPA-1659 – Repeated S-ketamine infusions in treatment-resistant depression (European Psychiatry
2014, Vol.29, pp.1-1)
Background: Ketamine, an N-methyl-D-aspartate antagonist, rapidly improves depressive symptoms in individuals with treatmentresistant depression. However, most trials using ketamine were limited to single administration and were performed with the racemic mixture of ketamine. The aim of this case series was to investigate the clinical efficacy of multiple intravenous administrations of S-ketamine in the acute treatment of treatment-resistant depression. MethodsIn 6 patients suffering from Major Depression (DSM-IV criteria) and being pharmacoresistant to at least 2 antidepressants, intravenous Ketamine treatment was started with a 40 minute administration of 0.25mg S-ketamine/kg body weight i.v. The treatment was performed over 3 weeks using 2 infusions per week. Patients were kept on their current pharmacotherapy regimen (including antidepressants). The patients were rated using the 21-item version of the Hamilton rating scale for depression (HAMD-21) before and 120 minutes after each ketamine infusion. ResultsIn 5 of 6 patients a strong improvement of depressive symptoms occurred already after the first ketamine infusion. The response could be stabilized by the following infusions. In 2 patients dissociative symptoms could be seen.
Conclusions Multiple administrations of ketamine appear to be well tolerated,
although negative effects on cognition have been described after longer use. The occurrence of dissociative symptoms in two patients in our study must be viewed as an unpleasant side effect. In the literature there is some evidence,
that S-ketamine has better tolerability than racemic ketamine but similar antidepressant effects.
And I have a few more if I find them.
S-ketamine for the treatment of depression (Psychiatria Fennica
2015 Vol. 46 pp 11-20)
Ketamine infusion has been reported to rapidly relieve depressive symptoms and
suicidal ideation in patients with treatment-resistant depression (TRD). It has also
been tested in electroconvulsive therapy (ECT) anaesthesia and has been suggested to
enhance the response to ECT. S-ketamine is less studied than a racemic mixture or
R-enantiomer in these patients.
S-ketamine is more potent as an anaesthetic and might
thus also have a better antidepressive effect. In this article we present recent
data concerning the antidepressive and adverse effects of S-ketamine compared with
racemic and R-ketamine in major depressive disorder (MDD), especially in TRD. Based on
recent literature, it is obvious that S-ketamine also possesses antidepressive
properties. In ECT anaesthesia, S-ketamine might enhance the antidepressive effect of
this treatment. S-ketamine may also be preferable when compared with other anaesthetics
regarding adverse cognitive effects.
Its adverse psychotomimetic effects may be
avoidable when used in anaesthetic doses. Although the data on S-ketamine at the
moment is only based on case reports and expert opinions rather than adequate
prospective randomized studies, it still may offer an important option when treating
severe and resistant depression
This is linked to electroconvulsive therapy.
