Clozapine - Tardive Dyskinesia Treatment
Once symptoms of tardive dyskinesia begin to appear, the damage is often irreversible even though these symptoms can flare up and recede at any time. Therapies involving additional drugs to counteract the effects often create new problems of their own or are known to exacerbate the problems the patient is already experiencing.
Alternative therapies involving natural herbs and vitamin supplements appear to show some promise, but are largely untested and not well researched. The best treatment for tardive dyskinesia is prevention or withdrawal from the medication altogether. However, sudden withdrawal is known to trigger dyskinetic symptoms and gradual reduction of the dosage appears to be more effective.
Another strategy for managing symptoms of tardive dyskinesia lies in switching the medication. While this may not be an option for all patients, those who are able to change their prescriptions safely may benefit from using a newer type of medication such as clozapine.
"Typical" vs. "Atypical"
Drugs used to treat psychosis such as schizophrenia fall into one of two categories. "Typical" refers to older, first-generation medications. Second generation medications are known as "atypical." Typical drugs largely make up drugs developed between the 1950s and 1970s. Atypical drugs consist of mainly those developed between the 1970s and 1990s.
Clozapine is one example of an early "atypical" drug. Although first developed in 1961, it did not arrive on the market until 1971. It was sold in Europe for only four years and then withdrawn because it was discovered that some patients on this medication developed a potentially fatal condition known as agranulocytosis, a condition affecting blood cells that can cause massive infections.
Eventually however, clozapine was found to treat symptoms of schizophrenia in patients that had become resistant to other drugs. In the 1980s, the Food and Drug Administration approved clozapine for this use under the condition that patients being treated receive regular blood screening against agranulocytosis.
Clozapine and Tardive Dyskinesia
While atypical medications such as clozapine were found to be "comparably effective in the treatment of acute mania" in a research study carried out at the University of Cincinnati, it should be known that such newer medications do not eliminate the risk of developing tardive dyskinesia. Patients receiving such medications may however experience a longer period before such symptoms arise.
Another study led one researcher to conclude that the only anti-psychotic medication having a possible lower risk for causing dyskinetic symptoms was clozapine. This particular researcher, Dr. John Kane, has spent several years studying tardive dyskinesia and the effects of various drugs. His conclusion was that clozapine, administered concurrently with a second neuroleptic medication known as sulpride, posed the lowest risk of patients developing tardive dyskinesia symptoms.
Like other anti-psychotic medications, sulpride is a dopamine antagonist. However, unlike other neuroleptics, sulpride appears to be far more selective, more narrowly targeting the specific dopamine receptor D2. Unfortunately, sulpride is not available in the United States.
Other Side Effects
Clozapine has been implicated in numerous minor conditions that include:
- Muscular stiffness
- Elevated glucose levels
- Sudden drop in blood pressure
A mandatory warning on all packages of clozapine also states that patients run the risk of seizures and cardiovascular problems, including inflammation of the heart muscle (myocarditis).