Second-Generation Antipsychotics for Treating Schizophrenia

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Second-Generation Antipsychotics for Treating Schizophrenia


Generic NameBrand Name
risperidoneRisperdal, Risperdal Consta

These medicines are available as tablets or injection (shot).

Risperdal Consta is given as a shot by a doctor every 2 weeks. Because a doctor gives the shot and it lasts longer than other medicines, some experts think this makes it more likely that a person will take enough medicine to get better.

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).

Why It Is Used

These medicines treat the symptoms of schizophrenia. They may also cause fewer movement side effects than first-generation antipsychotic medicines, such as haloperidol or chlorpromazine.

Because they may have fewer side effects, second-generation antipsychotics often are used first when a person is first diagnosed with schizophrenia. But some doctors feel that first-generation antipsychotics started at low doses may work just as well and at a lower cost.

How Well It Works

These medicines reduce or eliminate the positive symptoms (such as hallucinations or delusions) and sometimes help reduce the negative symptoms (such as lack of emotion or motivation) of schizophrenia.

Second-generation antipsychotics also may help reduce the risk of movement disorder side effects (such as tardive dyskinesia).1

Side Effects

The side effects of the new second-generation antipsychotic medicines vary.

Side effects that all these medicines may have include:

  • Feeling sleepy or tired.
  • Gaining weight.
  • Developing high cholesterol.
  • Developing high blood sugar.

The makers of Risperdal, Seroquel, and Zyprexa have warned that high blood sugar or type 2 diabetes may be more likely in people who are taking these medicines.

Among second-generation antipsychotic medicines with other side effects:

  • Aripiprazole has common side effects of headache, nausea, and constipation. There is little weight gain with this medicine.
  • Olanzapine may cause weight gain and insulin resistance. This can cause blood sugar levels to become too high. These are the most common side effects of olanzapine.
  • Quetiapine can cause constipation and dry mouth.
  • Risperidone sometimes causes reduced interest in sex, erection problems in men, and disturbances in a woman's menstrual cycle. It also may increase levels of the hormone prolactin. This can lead to larger breasts in both men and women.
  • Ziprasidone side effects most often include nausea and headache. Weight gain is not a big problem. Ziprasidone sometimes can slow down the heart. Ziprasidone should also not be used by people who have a history of cardiac arrhythmia.
  • Paliperidone may cause restlessness, movement disorders, rapid heartbeat, and sleepiness.

In rare cases, second-generation antipsychotic medicines can cause some people to develop neuroleptic malignant syndrome. This is a rare but life-threatening side effect of antipsychotics. The first signs usually include a fever between 38.9°C (102°F) and 39.4°C (102.9°F), a fast or irregular heartbeat, rapid breathing, and severe sweating.

In some instances, these medicines may cause body movements you can't control, including tardive dyskinesia. This side effect may be more likely when taking first-generation antipsychotic medicines.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

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 in the past and its side effects. Your doctor will help you find the best medicine for you.

The effects of the second-generation antipsychotic medicines have not been studied in children, older adults, or pregnant women. Older adults who take these medicines may develop side effects.

Taking medicine

If one antipsychotic medicine does not reduce or eliminate the symptoms of schizophrenia, your doctor may add another medicine or change to a different antipsychotic medicine.

How much medicine a person needs to treat schizophrenia varies for each person and with each medicine. If you take mood-stabilizing medicines along with antipsychotics, you may not have to take as much of the antipsychotic medicine. This will help reduce side effects.

Always take your medicine as directed by your doctor. Store it away from heat or light, and do not store it in the kitchen or bathroom, where heat and moisture may cause it to lose its strength.

If you miss a dose of medicine, take it as soon as you remember. But if it is close to the time of your next dose, skip the missed dose and continue to take the medicine according to schedule. Do not take double doses. Call your doctor if you have any questions about missed doses. Do not stop taking these medicines without telling your doctor.


Both first-generation and second-generation antipsychotic medicines may make a stroke more likely in older adults who have dementia.2

Sometimes people who have schizophrenia also need to take medicines for other illnesses. Other medicines may interact with medicines for schizophrenia. Talk to your doctor if you are taking other medicines.

People who have certain body movement disorders (such as Parkinson's disease or seizures) or liver disease may not be able take risperidone. Tell your doctor if you have any other health problems.

Talk to your doctor if you drink alcohol.

The second-generation antipsychotic medicines may pass into breast milk and cause problems in a baby, including behaviour changes. Talk with your doctor about this if you are breast-feeding.


To reduce interactions, ziprasidone should not be taken with certain medicines, such as amiodarone (Cordarone) or disopyramide (Rythmodan).

Ziprasidone can slow down the heart, so do not take it with other medicines that also do this, and do not take it if you have heart problems. While you are taking ziprasidone, your doctor may suggest that you get an electrocardiogram (EKG, ECG) to measure your heart's electrical activity.

Because ziprasidone does not cause a lot of weight gain, it may be a good choice for people with schizophrenia who also have diabetes.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Durham J (2009). Schizophrenia: A review of pharmacologic and nonpharmacologic treatments. US Pharmacist, 34(11): 1–5.
  2. Douglas IJ, Smeeth L (2008). Exposure to antipsychotics and risk of stroke: Self-controlled case series study. BMJ. Published online August 28, 2008 (doi:10.1136/bmj.a1227).


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Specialist Medical Reviewer Miklos Ferenc Losonczy, MD, PhD - Psychiatry
Last Revised January 14, 2011

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.