Last week in the Westmeath Topic, I discussed the types of medication prescribed for schizophrenia. This week I discuss the reasons different treatments are chosen.
Choice of Drug
No one drug can be considered significantly better than the others, however one may be better for one individual than another. For example, some are more sedating than others so may be suitable for patients who are agitated or cannot sleep. If one does not work so well, a different one is tried until a good response occurs. A good response to antipsychotic medication occurs in about 70% of cases. Symptoms such as agitation and hallucinations generally ease within a few days of starting medication. Symptoms like delusions usually subside within a few weeks and it can take several weeks for full improvement. Antipsychotic medication is normally continued long-term once symptoms improve. There is some evidence that the newer atypical antipsychotics give lower relapse rates than older typical antipsychotics. Newer atypical antipsychotics also appear to be more effective than older typical antipsychotics for negative symptoms of schizophrenia. Clozapine (Clozaril®) is often prescribed for people who have not responded adequately to treatment despite the use of adequate doses of at least two different antipsychotic drugs. At least one of the drugs should be an atypical antipsychotic before trying clozapine. Clozapine is very effective for psychotic symptoms including hallucinations and breaks from reality. Clozapine can sometimes cause a serious condition called agranulocytosis, a loss of the white blood cells which reduces the ability to fight infection. People who take clozapine must get their white blood cell counts checked weekly for the first 18 weeks and every two weeks after that for the first year and every four weeks thereafter. Other atypical antipsychotics do not cause agranulocytosis. The risk of agranulocytosis and the cost of blood tests is the main reason that clozapine is generally reserved for when other medication fails which is estimated to be 30% of cases.
For people who have only one episode of schizophrenia and who remain symptom free for two years with treatment, the medication may then be discontinued slowly under the supervision of a doctor; the patient must be closely monitored for relapse when medication is being discontinued.
Side-effects of antipsychotic drugs
Side-effects can occur and there is a trade-off between easing symptoms and side-effects from treatment. Different antipsychotic drugs cause different types of side-effects. Sometimes one drug causes side-effects in some people and not in others. Quite often, two or more different drugs have to be tried before one is found that is best suited.
Side effects which are more common with the older typical anti-psychotics include dry mouth, blurred vision, flushing and constipation. These tend to be worse at the start of treatment and may ease off as the person gets used to the drug. Chlorpromazine has a tendency to cause skin rash when the person is exposed to sunlight. Sunscreen must be used if going out in strong sun while taking chlorpromazine.
Drowsiness is also common but may be reduced by reducing the dose. Movement disorders can occur with typical antipsychotics. Movement disorders include Parkinson type symptoms, for example, tremor and muscle stiffness; Akathisia, which is like a restlessness of the legs; Dystonia, which is abnormal movements of the face and body and Tardive dyskinesia, which is a movement disorder that can occur with longer term treatment with antipsychotics. Tardive dyskinesia causes rhythm like, involuntary movements. It most commonly affects the mouth and can include lip-smacking, grimacing and tongue-rotating movements, although it can affect the arms and legs too. About 30% people treated with typical antipsychotics long term eventually develop tardive dyskinesia. Tardive dyskinesia is rarer nowadays as people are closely monitored for symptoms of tardive dyskinesia and the drug is changed once the symptoms start to develop.
If movement disorders are a problem, then other drugs may be used to try to counteract them. These include anti-cholinergic drugs such as biperiden (Akineton®). Tardive dyskinesia will not respond to treatment with anti-cholinergic drugs but usually resolves slowly after discontinuation of the typical antipsychotic. However it is irreversible in some cases. Propranolol (20 to 80 mg daily) can be prescribed by the doctor to control akathisia (restlessness).
The newer atypical antipsychotic drugs are less likely to cause movement disorder side-effects than typical antipsychotic drugs; this is why they are frequently the first choice for treatment. Atypical antipsychotics do have their own risks, particularly the risk of weight gain. Weight gain can occur and this may increase the risk of developing diabetes and heart problems (due to raised cholesterol) in the longer term; thus blood sugars and cholesterol levels should be monitored regularly. Weight gain appears to be a particular problem with clozapine and olanzapine. For example, studies show that olanzapine can cause weight gain of 5.4kg within 5 weeks of treatment and weight gain of 20kg or more after longer term treatment. Ziprasidone (Geodon®) and amisulpride (Solian®) tend to cause less weight gain than other atypical antipsychotics.
Antidepressants may be used in some cases, especially for people primarily showing negative symptoms. Research suggest that taking an antidepressant drug in addition to an antipsychotic drug may be better than an antipsychotic drug alone in treating negative symptoms of schizophrenia. An antidepressant drug may also be useful to treat depression which is common in people with schizophrenia. People who display manic episodes including excitement and agitation may benefit from mood stabilisers such as lithium carbonate or sodium valproate.
To be continued ….next week I discuss the long term outlook for people with schizophrenia.
Disclaimer: This article is meant to give a general overview of the topic discussed; for more specific and detailed information, please speak to a health care professional
Whelehans Pharmacy, Pearse Street and Clonmore, Mullingar. Tel 04493 34591. Eamonn’s full comprehensive article on schizophrenia is available in Whelehans on request or check www.whelehans.ie. Simply ask our staff for a free copy. References are also available upon request