APPROACHES
The following two tapering approaches are not absolute rules: they can be adapted to each situation, in particular to lengthen the tapering period (and reduce withdrawal effects). The percentage reduction (from 10 to 25%) may vary depending on the drug, the dosage and the difficulty of withdrawal. The advantage of these methods is that they are progressive, allowing you to gradually assess how you feel and adjust the pace of the reduction accordingly.
In the case of taking several psychiatric drugs, it is recommended to start the reduction of a single drug at a time and to check with the doctor and the pharmacist where to start.
You can use these approaches as a guideline, to reduce the risks associated with the reduction as much as possible, while knowing that you will have to adapt them to your situation.
The GAM Personal Guide provides information on the tapering method known as the 10% method. This suggests reducing the daily dosage by 10% of the initial dosage, in stages of variable duration, depending on the type of drug and the difficulties encountered.
Example of 10% reduction
Step 1: 100mg
Step 2: reduction of 10 mg (or 100 mg - 10%) to 90 mg.
Step 3: reduction of 10 mg to 80 mg.
Step 4: reduction of 10 mg to 70 mg.
Step 5: reduction of 10 mg to 60 mg.
You will find more detailed information, in particular on the division and the distribution of the doses on pages 102 to 106 of the GAM guide.
Another similar reduction approach is also known as the hyperbolic method which consists of a reduction in steps of 10%, but from the last dose.
Example of hyperbolic reduction
Step 1: 100mg
Step 2: reduction of 10 mg (or 100 mg - 10%) to 90 mg.
Step 3: reduction of 9 mg (or 90 mg – 10%) to 81 mg.
Step 4: reduction of 8.1 mg (or 81 mg -10%) to 72.9 mg.
Step 5: reduction of 7.29 mg (or 72.9 mg – 10%) to 65.61 mg.
As can be seen in this example, the dose reduction is less and less significant as the stages progress, in order to reduce the impact of withdrawal as much as possible. This approach builds on recent research by Mark Horowitz.
Horowitz, Mark Abie, Sameer Jauhar, Sridhar Natesan, Robin M. Murray, and David Taylor. 2021. “A Method for Tapering Antipsychotic Treatment That May Minimize the Risk of Relapse.” Schizophrenia Bulletin. must: 10.1093/schbul/sbab017 .
Horowitz, Mark Abie, and David Taylor. 2019. “Tapering of SSRI Treatment to Mitigate Withdrawal Symptoms.” The Lancet Psychiatry 6(6):538-46. must: 10.1016/S2215-0366(19)30032-X .
Community pharmacies and specific dosages
Often, when going through withdrawal, it can be difficult to access the doses of medication that correspond to the desired reduction, whether it is 10% or any other percentage. Indeed, the drugs that can be obtained in pharmacies with a prescription are generally marketed according to predefined dosages by the pharmaceutical companies that manufacture them. For example, sertraline (Zoloft) comes in 25 mg, 50 mg or 100 mg capsules, while olanzapine (Zyprexa) comes in 2.5 mg, 5 mg, 7.5 mg , 10, 15mg or 20mg. If we take the example of a person who is prescribed 100 mg of sertraline and who would like to reduce their medication in steps of 10%, they could have difficulty obtaining corresponding dosages, i.e. 90 mg, 80mg, 70mg, and so on. To meet this difficulty, some pharmacists can prepare more specific dosages called extemporaneous mixtures if requested in the prescription.
More specifically, the Quebec Association of Proprietary Pharmacists (AQPP) defines extemporaneous mixtures as follows:
An extemporaneous mixture is a drug preparation that the pharmacist prepares from the doctor's prescription in order to produce a targeted and very specific therapy for a patient. The pharmacist uses the extemporaneous mixture to manufacture a drug that is not commercially available or out of stock. In general, it is therefore not an alternative to a marketed drug, but rather a preparation that would otherwise not be accessible to the patient at the required dosage or in the pharmaceutical form corresponding to their needs.
Still according to the AQPP:
All pharmacies in Quebec can serve an extemporaneous mixture to their patients, but the preparation is not always made on site. If the pharmacy does not have the specialized equipment or the necessary facilities, the pharmacist may have recourse to a pharmacy specializing in these preparations. The preparing pharmacy will then give the extemporaneous mixture to the pharmacist responsible for the patient, who will then give it to their patient.
Reference: https://www.monpharmacien.ca/nouvelles/les-preparations-magistrales-a-quoi-ca-sert/
If you want to start a tapering process, these preparations could be an interesting option, because they can allow for a more specific reduction not limited to the predefined dosages made by pharmaceutical companies. You can discuss it with your doctor and your pharmacist to find out if this solution is right for you.
Here is a list of pharmacies in the Montréal area that can make specific dosages (extemporaneous mixtures). Call pharmacies in your area to check if they can offer this service.
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Morin Pharmacy
5955 Sherbrooke Street East
Montreal (Quebec) H1N 1B7
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Christian and Francis Shefteshy Pharmacy
5955 Gouin Boulevard West,
Montreal (Quebec) QC H4J 1E5
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Pharmacy El-Achkar, Jetha and Merrouni
965-T Boul. Cure-Labelle
Laval, Quebec, H7V2V7
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Paylan Pharmacy
8967 Boul. Le Jeune
Montreal Quebec H2M 1S1
Other guides explaining tapering methods are also available
Harm Reduction Guide to Coming Off Psychiatric Drugs , Will Hall
BENZODIAZEPINES: HOW THEY WORK AND HOW TO WITHDRAW
A Straight Talking Introduction To Psychiatric Drugs (Second Edition): The Truth About How They Work And How To Come Off Them. Joanna Moncrieff
Psychiatric Drug Withdrawal. A Guide for Prescribers, Therapists, Patients and their Families. Peter R. Breggin
Withdrawal from Prescribed Psychotropic Drugs. Peter Lehman
To inspire health professionals
A short guide to what every psychological therapist should know about working with psychiatric drugs
Pearson & Cohen Pharmacy
102 - 5025 Sherbrooke West
Westmount, QC H4A 1S9
ProxiMed Pharmacy
5531 Westminster
Cote St Luc, QC H4W 2J2
Linda Frayne Pharmacist
400 5858 Cote-des-Neiges
Montreal, QC H3S 1Z1