These medicines are available as tablets, a concentrated
liquid, or an injection (shot). Long-acting formulas that are given every 2 to
4 weeks are available for fluphenazine and haloperidol.
How It Works
Experts don't know exactly how these antipsychotic medicines work. They think these medicines work because of
how they affect brain chemicals (neurotransmitters). They usually are started at low doses to avoid side
Why It Is Used
First-generation antipsychotics are
used to reduce anxiety and agitation that often happen in
schizophrenia. They can also reduce problems with
thinking or remembering (cognitive impairment) and reduce or
How Well It Works
First-generation antipsychotics can
reduce or control psychosis and improve thinking, mood, and behavior. These
medicines may help you return to a more normal daily life while living with
First-generation antipsychotics may work
differently in different people. For some people, these medicines may help with
many symptoms, while other people may have to try other antipsychotic medicines
to find the one that works best for them.
First-generation antipsychotic medicines
can cause mild to severe problems with body movements.
- Mild movement problems include restlessness,
tremors, and rigid muscles. You may be able to reduce
or stop these problems by taking a smaller dose of the medicine or by switching
to another medicine. Your doctor also may be able to prescribe another medicine
to block the movement problems.
- A severe movement problem is
tardive dyskinesia, which causes unusual body
movements that you cannot control. Signs may include lip-smacking or continuous
chewing, tongue-twitching or thrusting the tongue out of the mouth, or quick
and jerky movements (tics) of the head.
Other serious side effects include:
Other common, mild side effects include:
First-generation antipsychotics may raise levels of the
hormone prolactin. This can lead to breast enlargement in both men and women and abnormal menstrual cycles in women.
See Drug Reference for a
full list of side effects. (Drug Reference is not available in all
What To Think About
If you have any significant
side effects while taking an antipsychotic, call your doctor right away. You
may need another type of medicine, or the dose may need to be lowered.
There is some evidence of a link between first-generation antipsychotics
(such as haloperidol or thioridazine) and an increase in cardiac arrest (heart
stopping) or abnormal heartbeat.1 But it is not yet
clear whether the risk is linked with the medicines or with
If you have trouble taking antipsychotic medicines
every day, you may be able to get a shot every 2 to 4 weeks. Talk with your
doctor about whether this would be better for you.
likely will start by taking only a little of the medicine and then slowly take
more. It may take several weeks before you know the medicine is working and
know the best dose. If you do not see any benefits within 6 weeks, ask your
doctor if you need to try another type of medicine.
abruptly stop taking these medicines. Do not skip doses. If you forget to take
a dose, take it as soon as you remember, but do not take
more than one dose at a time.
The first-generation and
second-generation antipsychotic medicines both can help the symptoms of
schizophrenia. Which medicine is best for you usually depends on how well a
medicine has worked for you in the past and its side effects. Your doctor will
help you find the best medicine for you.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Durham J (2009). Schizophrenia: A review of pharmacologic and nonpharmacologic treatments. US Pharmacist, 34(11): 1-5.