In order to have an assessment appointment, you will need to have a referral letter from your GP or psychiatrist including information about your past and current treatments, physical health, and copies of any correspondence about your mental health from other services. In addition to this, patients will be asked to complete a standardised online questionnaire. The purpose of this is to add to the referral information and clinical assessment.
You will also be asked to do an ECG; your GP clinic will be able to arrange this for you if you have not had one done in the last year.
The purpose of the assessment appointment is to determine your suitability for treatment with ketamine. The assessment appointment may take place in person in Tauranga or online using an audio-visual link.
Treatment is with an oral formulation of ketamine, or an intranasal formulation of esketamine. Ketamine is used ‘off-label’ for depression in New Zealand, however its derivative, esketamine, is Medsafe approved for treatment-resistant depression in New Zealand.
Treatment with oral ketamine involves a titration appointment. The initial dose of ketamine is calculated based on the patient’s body weight, aiming for a dose of 0.5mg per kilogram of body weight. Your blood pressure will be checked before and after treatment, and you will be asked about side effects such as nausea, relaxation, or dissociation. If there is no decrease in blood pressure or side effects, you may be given a slightly higher dose after a delay.
Please avoid alcohol and benzodiazepine drugs for 12 hours prior to taking ketamine, and for 24 hours afterwards.
On the day of treatment, please ensure that you have not eaten for two hours beforehand. Most patients are ready to leave again within 60-90 minutes, but you will need to have someone with you to drive you to your accommodation afterwards. Some patients feel unsteady on their feet for a substantial period after taking treatment, and in that case will need to wait longer. Titration can be boring, so please feel free to bring a book. You will be unable to drive for ten hours after treatment.
You MUST NOT drive a car, drink alcohol, sign legal documents, or look after dependents for at least ten hours after taking ketamine.
Our dedicated clinic team will check up on your progress within 72 hours and advise you on what course to take from there.
Treatment with ketamine and its derivatives has a high likelihood of producing a positive response – about 70% of people will have a significant reduction in symptoms. However, some may not be able to achieve a more prolonged effect.
The main risk of using ketamine is of short term side effects. These are typically mild and brief, particularly with the oral route of administration, however there have been reports of patients experiencing hallucinations or dysphoria on oral ketamine. This is why close follow up is required, to balance effectiveness with side effects, and also the reason why titration occurs on our premises. There is some risk, with the oral route, that it may be difficult and time consuming to find the correct dose. Intranasal esketamine has a very simple and rapid titration protocol by contrast.
The side effects of ketamine include bladder symptoms; this is known from studies of ketamine abusers, who often use high doses of ketamine by injection or snorting. Oral ketamine lozenges, which are of low dose and cannot be injected, are of little interest to ketamine abusers.
There is a risk of dependence on ketamine developing. Dependence means the development of withdrawal symptoms in between doses and the building of tolerance. This is not the same as reliance, in which a patient’s symptoms may relapse after stopping the medication. In order to reduce the risk of dependence, we space out doses as much as we can, and minimise doses. It seems that this risk is much higher in people using ketamine via the intravenous or intranasal routes.
Ketamine patients should have six-monthly liver function tests to make sure that there is no liver inflammation resulting from ketamine use.
We encourage patients to bring a support person who can sit with them, drive them home from the appointment, and let clinic staff know of any concerns during treatment. We wait until side effects are gone before allowing patients to leave.
The person may not feel like doing much for the rest of the day, and must not drive or operate machinery afterwards. Some patients become emotional during treatment, and they may appreciate talking to a caregiver about these experiences.