Effect of long-term Risperdal treatment and dopamine levels

[3jsd]

Hi,

I was wondering about a patient I encountered while shadowing. The patient said that he had taken Risperdal 37.5 mg by injection for a year and two months for schizophrenia, but the doctors had later decided that he did not in fact have schizophrenia and based on a review of the symptoms and discontinued the Risperdal. How long will it take for this person's dopamine levels to return to normal? I know that Risperdal decreases the amount of dopamine in the brain. Is it possible that the patient's dopamine levels will return to normal functioning or are his dopamine levels permanently damaged? How long would it take for them to return to normal? Thanks.

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[dl2dp2]

Firstly, Risperdal (and all the antipsychotics) does NOT decrease the level of dopamine in your brain. It blocks the dopamine RECEPTOR. So, in theory, once the drug degrades (i.e. a few days), the quantity of dopamine ACTIVITY goes back to as if there were no Risperdal present. However, this is not "normal", since whatever situation prompted the initiation of that drug in the first place presumably represented some kind of dysfunction.

However, the effect of Risperdal on psychosis is NOT generally thought to be mediated by short term blockade of dopamine receptors. It's yet controversial, but likely has to do long term neuronal remodeling at the circuitry level, and nobody knows what happens exactly when you take these drugs in the long run. Some think that it does very bad things to your brain. Others provided evidence that in fact some of these drugs are neuroPROTECTIVE in people who develop a primary psychotic disorder and prevents further loss of certain neurons--one may want to think of schizophrenia as a developmental neurodegenerative disorder--a dementia in adolescence (i.e. the original conceptualization of dementia preacox). Epidemiological work suggests that earlier initiation and long-term compliance of antipsychotic medications (the evidence is especially strong for Clozaril) correlate with a positive outcome in terms of occupational attainment and self-independence in chronically psychotic patients. But it's not clear whether this is a cause or an effect, or if it's simply due to a confound.

There is actually a very complicated answer to your seemingly simple question, and it gets at some of the core and most fascinating issues in psychiatric practice. I would encourage you to ask your attendings about them and read more on your own.

 

[kugel]

Sluox, excellent concise answer. I may well save that as an overview of the controversies about antipsychotics.

OP, there's also the issue of whether the pt never had schizophrenia, or whether it later looked like there was no schizophrenia because the disorder was treated. Unless you have access to a very thorough and careful examination from when the pt was originally diagnosed, we may never know exactly what the first doc saw. Everything gets distorted with time, diagnosis, patient's memory, family's memory, etc.

 

[3jsd]

Thanks! So in theory the dopamine activity should go back as soon as it degrades, but no one knows for sure what the long-term effects of Risperdal are on dopamine levels (in this situation)?

 

[whopper]

I think the question was answered. Once the medication it out of the system, it no longer has effects on the body.

There are some permanent side effects that could happen such as tardive dyskinesia, though it's not too common.

It is possible the medication does have long term effects that could have developed aside from TD, but the bottom line is if so, there's not too much data on it. Several medications effects are not studied over the course of several years. There is data, for example, that long-term use of antidepressants poses benefits that were not known until a few years ago because this knowledge required that a large number of people be followed for several years after starting it.

People schizophrenia develop a phenomenon known as neuroprotection while on an atypical antipsychotic. In schizophrenia, a person's brain degenerates unless the disorder is treated. Long term use of an atypical antipsychotic preserves the brain. This, however, is only for this with a schizophrenia per studies, though there is reason to believe the same phenomenon is going on in schizoaffective disorder and some other chronic psychotic disorders.

Off on a tangent, one of the benefits I have with working in a forensic psychiatric unit is I have much more liberty to stop patient's meds if I suspect the person is not truly mentally ill with a non-substance use Axis I disorder. So far, I've had 10 patients that were diagnosed with a psychotic disorder or bipolar disorder by several doctors, that when taken off of meds, even for several months did not show any signs or symptoms of the disorders.

Unfortunately, this only strengthened my fear that there are plenty of people out there, misdiagnosed, and the misdiagnosis will only further carry on. When a doctor sees a prior diagnosis, several unfortunately keep that diagnosis without verifying the credibility and validity of the original. Once a patient is diagnosed as psychotic or manic, and put on a medication, then given to a new doctor, it's very difficult for the new doctor to tell what was going before the medication started on unless meticulous notes were taken by the diagnosing doctor.

I just took a guy off of antipsychotics except for Seroquel 25 mg Qdaily that's up for attempted murder. The guy so far shows no signs or symptoms of psychosis despite having a schizoaffective disorder diagnosis (for years), and it's been several weeks he's been on that miniscule dosage. I'm suspecting that the moment I stop his Seroquel, he's going to start feigning symptoms because he doesn't know the dosages where it's supposed to have an antipsychotic benefit. He doesn't know that at 25 mg of that stuff, it doesn't treat psychosis, and given that I've been documenting his coherent behavior for weeks, his attempt to plead not guilty by reason of insanity isn't exactly going to hold much weight.

 

[3jsd]

Ok thank you guys 🙂