Ketamine is a safe and well-tolerated medication that is routinely given in the outpatient setting and for take home use for certain pain conditions. It is a preferred anesthetic agent for its safety profile, particularly around the lack of suppression to respiratory drive, and with some increase in blood pressure, which can be beneficial in surgery. At the lower doses used in treatment for mental health conditions, these concern are further mitigated.
Medical clearance prior to treatment is focused on cardiovascular health as there is temporary increase in blood pressure at the time of treatment. Basic medical management with antihypertensive medication can resolve this issues. Blood pressure is checked routinely during treatment, with medication provided if needed. In some cases, a more comprehensive cardiologist clearance may be indicated.
Provision of ketamine in medical setting for mental health treatment is not associated with abuse based on research studies. In the community, ketamine can be abused by users who need increasing doses to achieve the same effects – a tolerance phenomena, that results in dependence and psychological craving. These escalating doses and frequency of use increase the risk for cystitis – an inflammatory bladder condition. With more frequent provision of ketamine in the medical setting, the risk of cystitis is increased, though remains low. Patient with a history of cystitis may be at increased risk for reactivation.
It is possible to have transient side effects with the medical provision of ketamine – that typically resolve within 4 hours, and may be pre/treatable with medication:
- Blurred vision
- Nausea, vomiting
- Dry mouth
- Impaired coordination
- Impaired concentration
The literature around ketamine provision describes an ’emergence phenomena’, in approximately 10-20% of cases, in which a patient may experience subjective distress with psychological or physical restlessness. This experience has been more clearly reported when ketamine is provided for procedures, which involve disruption to body integrity and pain. In the event of such an emergence experience, low dose anxiolytic medication has been beneficial.
There are also rare psychological and psychiatric risks associated with treatment, notable switching into mania for bipolar patients, who may not yet be diagnosed as such. While rarely described, it is possible that sustained perceptual disturbances, alternations in cognition, reality testing or subjective distress stemming from treatment may persist beyond that acute treatment.