Risperdal aka risperidone, an atypical antipsychotic often prescribed off-label as a "shut-up" pill for whatever, comes in these forms:
from Risperdal Official FDA Information
- Risperdal® Tablets are available in 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, and 4 mg.
- Risperdal® Oral Solution is available in a 1 mg/mL strength.
- Risperdal® M-TAB® Orally Disintegrating Tablets are available in 0.5 mg, 1 mg, 2 mg, 3 mg, and 4 mg. The range of available dosages and existence of the liquid makes slow tapering relatively easy.
- Plus, from http://www.drugs.com...dal-consta.html, Risperdal Consta injections of 12.5 mg, 25 mg, 37.5 mg, or 50 mg risperidone every 2 weeks
The psychoactive effect is due to risperidone plus its active metabolite paliperidone (9-hydroxy-Risperidone).
Following oral administration of solution or tablet, mean peak plasma concentrations of Risperidone occurred at about 1 hour. Peak concentrations of 9-hydroxyRisperidone occurred at about 3 hours in extensive metabolizers, and 17 hours in poor metabolizers.....
The pharmacokinetics of Risperidone and 9-hydroxyRisperidone combined, after single and multiple doses, were similar in extensive and poor metabolizers, with an overall mean elimination half-life of about 20 hours.
Also see the journal article Howland, 2010 Potential adverse effects of discontinuing psychotropic drugs. Part 3: Antipsychotic, dopaminergic, and mood-stabilizing drugs. http://survivinganti...ndpost__p__7840
Abrupt discontinuation of antipsychotic drugs in patients with schizophrenia is associated with earlier, and often more severe, illness episodes than are seen with gradual discontinuation. Antipsychotic drugs can cause various abnormal motor syndromes, but abruptly stopping them has been associated with the seemingly paradoxical development of similar motor syndromes, such as withdrawal dyskinesias, parkinsonian symptoms, dystonias, and neuroleptic malignant syndrome.
Dopamine-releasing and dopamine-agonist drugs are used to treat some of the motor syndromes caused by antipsychotic drugs, but their abrupt discontinuation can also be associated with abnormal syndromes. When antipsychotic drugs, lithium, or certain anticonvulsant drugs are used for treatment of bipolar disorder, rapid versus gradual discontinuation is more likely to lead to greater mood instability and manic relapse.
If necessary, these medications should be gradually tapered to minimize all types of adverse discontinuation effects. Patients should be educated about the possible adverse effects of abrupt medication discontinuation.
As with other psychiatric drugs, do not taper Risperdal by taking a dose every other day! This causes a fluctuating level of the drug in your nervous system and can make you very sick.
A conservative taper is a drop of 10% from the previous dosage every few weeks. Some people find they can go faster and some people find they have to go slower -- they can only tolerate decreases of a fraction of a milligram at a time. See Why taper by 10% of my dosage?
Tapering off injectable Risperdal Consta
Risperdal may be administered via injection every 2 weeks. This form is called Risperdal Consta. It comes in a range of dosages: 12.5 mg, 25 mg, 37.5 mg, or 50 mg.
One can taper the injections simply by reducing the amount of liquid injected. This is probably the safest way to go off Risperdal Consta -- but it requires the cooperation of a doctor.
If you wish to switch to the tablet form to taper (see below), the following is important http://www.drugs.com...onsta.html#S2.8 :
After a single intramuscular (gluteal) injection of RISPERDAL® CONSTA®, there is a small initial release of the drug (< 1% of the dose), followed by a lag time of 3 weeks. The main release of the drug starts from 3 weeks onward, is maintained from 4 to 6 weeks, and subsides by 7 weeks following the intramuscular (IM) injection. Therefore, oral antipsychotic supplementation should be given during the first 3 weeks of treatment with RISPERDAL® CONSTA® to maintain therapeutic levels until the main release of risperidone from the injection site has begun [see Dosage and Administration (2)]. Following single doses of RISPERDAL® CONSTA®, the pharmacokinetics of risperidone, 9-hydroxyrisperidone (the major metabolite), and risperidone plus 9-hydroxyrisperidone were linear in the dosing range of 12.5 mg to 50 mg.
The combination of the release profile and the dosage regimen (IM injections every 2 weeks) of RISPERDAL® CONSTA® results in sustained therapeutic concentrations. Steady-state plasma concentrations are reached after 4 injections and are maintained for 4 to 6 weeks after the last injection....
....The apparent half-life of risperidone plus 9-hydroxyrisperidone following RISPERDAL® CONSTA® administration is 3 to 6 days, and is associated with a monoexponential decline in plasma concentrations. This half-life of 3–6 days is related to the erosion of the microspheres and subsequent absorption of risperidone. The clearance of risperidone and risperidone plus 9-hydroxyrisperidone was 13.7 L/h and 5.0 L/h in extensive CYP 2D6 metabolizers, and 3.3 L/h and 3.2 L/h in poor CYP 2D6 metabolizers, respectively. No accumulation of risperidone was observed during long-term use (up to 12 months) in patients treated every 2 weeks with 25 mg or 50 mg RISPERDAL® CONSTA®. The elimination phase is complete approximately 7 to 8 weeks after the last injection....
If you are switching from the injection to the extended-release tablets, you need to be careful about the overlap -- you could be taking a high dose if you have recently had an injection and you add tablets. Probably the safest time to make the switch to a lower-dosage daily tablet would be in the 5th week, when the injection is wearing off.
This reference, from the UK Psychiatric Pharmacy Group (now College of Mental Health Pharmacy), is the only one I could find regarding switching from the Consta injection to a risperidone tablet:
It takes about 6 weeks following an injection for the levels in the blood to fall below a sub-therapeutic level. Switching a patient to an oral preparation should be started about 5 weeks after the final injection. The manufacturer suggests starting at a dose of 2mg/day of risperidone and gradually increasing if necessary according to response over the following week.
Cutting up the tablets with a pill splitter
This can work, but if you are sensitive to small variations in dosage, cutting up pills is not very exact. For more exact doses, weigh fragments with an electronic digital scale.
Keep the pieces you don't use in a clean pill bottle labeled with the dosage for future use.
Use an electronic digital jeweler's scale to weigh small amounts
If you are sensitive to dosage changes, you may wish to be more precise in your measurements so you can taper at a measured rate. A digital scale, which can be bought for about $30, is useful. Instructions here.
Have risperidone made into smaller dosage capsules by a compounding pharmacy
Compounding pharmacies can crush the tablets and put the powder into smaller capsules by weight. You will need a doctor's prescription for this telling the pharmacy exactly how much to put in a capsule and how many capsules to make.
Use the Risperdal liquid solution
Titrating using a liquid is very good for very small measured decreases in dosage, allowing more precise measurements.
from Risperdal Official FDA Information
Risperdal® Oral Solution can be administered directly from the calibrated pipette, or can be mixed with a beverage prior to administration. Risperdal® Oral Solution is compatible in the following beverages: water, coffee, orange juice, and low-fat milk; it is NOT compatible with either cola or tea.
If you mix it with liquid to titrate, you may find you need to slightly adjust the dose up or down. Those adjustments would be by tenths or even hundredths of a milligram.
For tips about using an oral syringe for doses of liquid medication, see http://survivinganti...ring-techniques
Use a tiny 1mL syringe to measure dosages less than 1mg, to hundredths of a milligram.
Edited by Altostrata, 14 October 2014 - 01:42 PM.