Research in schizophrenia meds has made huge difference

Research into antipsychotic medications has resulted in big improvements over just the last few years.

Second generation antipsychotic medications were introduced just 15 years ago. Until then, the drugs used to treat schizophrenia were responsible for serious side effects in many people.

Medications from this era included haldol and caused a movement disorder known as tardive dyskinesia in some patients. The longer patients took the medication, the more likely they were to develop tardive dyskinesia. With every year on medication, an additional five percent of patients developed the disorder.

Not surprisingly, when the next generation of antipsychotic medications came on the market, they were eagerly welcomed as effective alternatives that did not cause this disturbing condition. These medications are known as atypical antipsychotics and include drugs such as clozapine, risperidone, olanzapine and seroquel.

However, even though the newer drugs were better than the first generation of antipsychotic drugs, over time it has become apparent they have their own set of potentially serious side effects.

Current antipsychotic meds are associated with increased incidence of weight gain, hyperlipidemia and diabetes, the so-called metabolic syndrome.

An FDA warning about these side effects was first issued in 2003 and since then the risk has been confirmed and quantified in many studies. Clinically significant weight gain occurs with clozapine, olanzapine, seroquel and risperidone. On average, the weight gain is roughly four kilograms in 10 weeks on olanzapine and about half that on risperidone.

Further, the same relative relationship exists for elevated total cholesterol, triglycerides and diabetes.

Less well recognized is that diabetes was noted to be more common among schizophrenic individuals before drugs were ever introduced for this disease. Reports dating from as early as 1899 as well as 15 publications between 1919 and 1946 commented on an elevated incidence of these symptoms among those with schizophrenia.

In more recent studies, 15 percent of drug naive, first episode patients had impaired glucose tolerance compared to zero percent in age and gender matched non-schizophrenic volunteers.

These numbers could be due to genetic predisposition or lifestyle issues such as diet or lack of physical activity. Elevated cortisol secretion found in this disease could also affect glucose tolerance in this population.

Regardless of the cause in the absence of medication, there is no doubt that the atypical antipsychotic drugs do increase an already elevated risk for obesity, hyperlipidemia and diabetes.

Since these are potentially life-threatening side effects, new attempts to launch a third generation of antipsychotic medications are underway. Research is ongoing to develop medications that have a reduced incidence of these side effects while still providing effective relief of psychotic symptoms.

Aripiprazole and ziprasidone, already approved in the US, appear to be a significant improvement, but are not available yet in Canada. Other drugs currently under development also show promise. Bifeprunox appears to be the most promising and closest to approval.

This ongoing search for improved treatment with less side effects is a great example of the significance of continued research in medicine.

Okanagan Clinical Trials currently has a study examining an investigational medication in the treatment of schizophrenia. Please contact our office for more information.


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