A person who is psychotic is out of touch with reality. S/he 
may "hear voices" or have strange and untrue ideas (for example, 
thinking that others can hear his thoughts, or are trying to harm 
him, or that he is the President of the United States or some 
other famous person). He may get excited or angry for no apparent 
reason, or spend a lot of time off by himself, or in bed, sleeping 
during the day and staying awake at night. He may neglect his 
appearance, not bathing or changing clothes, and may become 
difficult to communicate with--saying things that make no sense, 
or barely talking at all. 

These kinds of behaviors are symptoms of psychotic illness, 
the principal form of which is schizophrenia. All of the symptoms 
may not be present when someone is psychotic, but some of them 
always are. Antipsychotic medications, as their name suggests, 
act against these symptoms. These medications cannot "cure" the 
illness, but they can take away many of the symptoms or make them 
milder. In some cases, they can shorten the course of the illness 
as well. 

There are a number of antipsychotic medications available. 
They all work; the main differences are in the potency--that is, 
the dosage (amount) prescribed to produce therapeutic effects--and 
the side effects. Some people might think that the higher the 
dose of medication, the more serious the illness, but this is not 
always true. 

A doctor will consider several factors when prescribing an 
antipsychotic medication, besides how "ill" someone is. These 
include the patient's age, body weight, and type of medication. 
Past history is important, too. If a person took a particular 
medication before and it worked, the doctor is likely to prescribe 
the same one again. Some less potent drugs, like chlorpromazine 
(Thorazine), are prescribed in higher numbers of milligrams than 
others of high potency, like haloperidol (Haldol). 

If a person has to take a large amount of a "high-dose" 
antipsychotic medication, such as chlorpromazine, to get the same 
effect as a small amount of a "low-dose" medication, such as 
haloperidol, why doesn't the doctor just prescribe "low-dose" 
medications? The main reason is the difference in their side 
effects (actions of the medication other than the one intended for 
the illness). These medications vary in their side effects, and 
some people have more trouble with certain side effects than 
others. A side effect may sometimes be desirable. For instance, 
the sedative effect of some antipsychotic medications is useful 
for patients who have trouble sleeping or who become agitated 
during the day. 

Unlike some prescription drugs, which must be taken several 
times during the day, antipsychotic medications can usually be 
taken just once a day. Thus, patients can reduce daytime side 
effects by taking the medications once, before bed. Some 
antipsychotic medications are available in forms that can be 
injected once or twice a month, thus assuring that the medicine is 
being taken reliably. 

Most side effects of antipsychotic medications are mild. 
Many common ones disappear after the first few weeks of treatment. 
These include drowsiness, rapid heartbeat, and dizziness when 
changing position. 

Some people gain weight while taking antipsychotic medications 
and may have to change their diet to control their weight. Other 
side effects that may be caused by some antipsychotic medications 
include decrease in sexual ability or interest, problems with 
menstrual periods, sunburn, or skin rashes. If a side effect is 
especially troublesome, it should be discussed with the doctor who 
may prescribe a different medication, change the dosage level or 
schedule, or prescribe an additional medication to control the 
side effects. 

Movement difficulties may occur with the use of antipsychotic 
medications, although most of them can be controlled with a 
prophylactic medication. These movement problems include muscle 
spasms of the neck, eye, back, or other muscles; restlessness and 
pacing; a general slowing-down of movement and speech; and a 
shuffling walk. Some of these side effects may look like 
psychotic or neurologic (Parkinson's disease) symptoms, but 
aren't. If they are severe, or persist with continued treatment 
with an antipsychotic, it is important to notify the doctor, who 
might either change the medication or prescribe an additional one 
to control the side effects. 

Just as people vary in their responses to antipsychotic 
medications, they also vary in their speed of improvement. Some 
symptoms diminish in days, while others take weeks or months. For 
many patients, substantial improvement is seen by the sixth week 
of treatment, although this is not true in every case. If someone 
does not seem to be improving, a different type of medication may 
be tried. Drug treatment for a psychotic illness can continue for 
up to several months, sometimes even longer. 

Even if a person is feeling better or completely well, he 
should not just stop taking the medication. Continuing to see the 
doctor while tapering off medication is important. Some people 
may need to take medication for an extended period of time, or 
even indefinitely, to remain symptom-free. These people usually 
have chronic (long-term, continuous) schizophrenic disorders, or 
have a history of repeated schizophrenic episodes, and are likely 
to become ill again. Also, in some cases a person who has 
experienced one or two severe episodes may need medication 
indefinitely. In these cases, medication may be continued in as 
low a dosage as possible to maintain control of symptoms. This 
approach, called maintenance treatment, prevents relapse in many 
people and removes or reduces symptoms for others. 

While maintenance treatment is helpful for many people, a 
drawback for some is the possibility of developing long-term side 
effects, particularly a condition called tardive dyskinesia. This 
condition is characterized by involuntary movements. These 
abnormal movements most often occur around the mouth, but are 
sometimes seen in other muscle areas such as the trunk, pelvis, or 
diaphragm. The disorder may range from mild to severe. 

For some people, it cannot be reversed, while others recover 
partially or completely. Tardive dyskinesia is seen most often 
after long-term treatment with antipsychotic medications. There 
is a higher incidence in women, with the risk rising with age. 
There is no way to determine whether someone will develop this 
condition, and if it develops, whether the patient will recover. 
At present, there is no effective treatment for tardive 
dyskinesia. The possible risks of long term treatment with 
antipsychotic medications must be weighed against the benefits in 
each individual case by patient, family, and doctor. 

Two approaches that are designed to provide the advantages of 
medication while reducing the risks of tardive dyskinesia and 
other possible side effects are sometimes used in long-term 
treatment. They are a "low-dosage" approach that uses far lower 
maintenance dosages of antipsychotic medications than have 
generally been employed, and an "intermittent dosage" treatment 
that involves stopping the medication when the patient is symptom-
free and beginning it again only when symptoms reappear. 

In 1990, clozapine (Clozaril), an "atypical" antipsychotic 
drug, was introduced in the United States. In clinical trials, 
this medication was found to be more effective than traditional 
antipsychotic medications in individuals with treatment-resistant 
schizophrenia, and the risk of tardive dyskinesia is lower. 
However, because of the potential side effect of a serious blood 
disorder, agranulocytosis, patients who are on clozapine must have 
a blood test each week. The expense involved in this monitoring, 
together with the cost of the medication, has made maintenance on 
clozapine difficult for many persons with schizophrenia. 

Antipsychotic medications can also produce unwanted effects 
when taken in combination with other medications. Therefore, the 
doctor should be told about all medicine being taken, including 
over-the-counter preparations, and the extent of the use of 
alcohol. Some antipsychotic medications interfere with the action 
of antihypertensive medications (taken for high blood pressure), 
anticonvulsants (taken for epilepsy), and medications used for 
Parkinson's disease. Some antipsychotic medications add to the 
effects of alcohol and other central nervous system depressants, 
such as antihistamines, antidepressants, barbiturates, some 
sleeping and pain medications, and narcotics. 


U.S. Department of Health and Human Services 
Public Health Service 
National Institutes of Health 
National Institute of Mental Health