Antipsychotic Medications Side effects and More




Antipsychotic medications can reduce or relieve symptoms of psychosis, such as delusions (false beliefs) and hallucinations (seeing or hearing something that is not there). Formerly known as major tranquilizers and neuroleptics, antipsychotic medications are the main class of drugs used to treat people with schizophrenia. They are also used to treat people with psychosis that occurs in bipolar disorder, depression and Alzheimer’s disease. Other uses of antipsychotics include stabilizing moods in bipolar disorder, reducing anxiety in anxiety disorders and reducing tics in Tourette syndrome.

Antipsychotic medications can help to calm and clear confusion in a person with acute psychosis within hours or days, but they can take up to four or six weeks to reach their full effect. These medications can help to control symptoms, but they do not cure the underlying condition. When taken over a longer term, antipsychotics can help to prevent further episodes of psychosis.

While antipsychotic medications can help some people with psychosis and mood disorders, these drugs can have serious side-effects. The aim of medication treatment is to reduce and control symptoms while keeping side-effects at a minimum.

Combining antipsychotic medication with other therapy and support can help people to manage symptoms and improve quality of life. Family therapy, peer support, school and job counselling, and housing and employment supports can all be helpful. Some therapists now offer cognitive-behavioural therapy to help people cope with voices and other auditory hallucinations.

Taking care of your physical health is especially important if you take antipsychotic medication. Both schizophrenia and the medications used to treat it can increase the risk of diabetes and other serious health problems. Getting regular checkups and medical care can help you to have good physical health. Eating a nutritious diet, exercising regularly and getting enough sleep can also help you to get and stay well.

Do I need this treatment?

Psychosis; can be dangerous, frightening, isolating and disabling. Symptoms of psychosis, such as delusions and hallucinations, may come on gradually and build up over time, or they may come on rapidly. People experiencing psychosis may not be aware that the experiences they are having are not normal. To them, what is happening in their minds is very real.

Recognizing and treating psychosis in the early stages greatly improves a person’s ability to recover and to lead a satisfying and rewarding life. Family, friends, colleagues and health providers play an important role in recognizing the signs of psychosis and in encouraging the person to get treatment. However, the symptoms of psychosis can sometimes lead to a breakdown in the person’s relationships with the people who might be most able to help him or her get treatment. Family members and others who support a person with psychosis may wish to seek support themselves, for example, from a family support group.

People with anxiety and mood disorders may benefit from taking antipsychotics in addition to antidepressants or mood stabilizers. When used in this way, antipsychotics may help to control symptoms such as irritable or depressed mood, disorganized thinking, and trouble concentrating and remembering.

What does Antipsychotic Medications do?

Psychosis is believed to be caused, at least in part, by overactivity of a brain chemical called dopamine, and antipsychotics are thought to work by blocking this dopamine effect. This blocking helps to make the symptoms of psychosis—such as voices and delusions—less commanding and preoccupying, but it does not always make them go away completely. People may still hear voices and have delusions, but they are more able to recognize what isn’t real and to focus on other things, such as work, school or family.

Side effects of Antipsychotic Medications

Antipsychotic medication can cause unpleasant side-effects, especially when the symptoms are severe and a higher dose of medication is used. Side-effects should become mild or at least tolerable when the dose is reduced and as your body adjusts to the presence of the drug.

Most side-effects will go away when you stop taking the drug. There is a risk, however, of a condition that causes people to make involuntary movements, known as tardive dyskinesia, which can be permanent.

Some people accept the side-effects as a trade-off for the relief these drugs can bring. Others find the side-effects distressing and may choose not to take the medication.

Check the information given to you by your doctor or pharmacist to find out the specific side-effects of any drug you have been prescribed. If you are troubled by any of these effects, it is best to continue to take your medication as prescribed and let your doctor know as soon as possible. Your doctor may:

  • adjust your dose
  • prescribe other medications to help control side-effects
  • change your medication.


Side effects of antipsychotics


  • Movement effects: Tremors, muscle stiffness and tics can occur. The higher the dose, the more severe these effects. The risk of these effects may be lower with the second generation medications than with the older drugs. Other drugs (e.g., benztropine [Cogentin]) can be used to control the movement effects.
  • Dizziness: Feelings of dizziness may occur, especially when getting up from a sitting or lying position.
  • Weight gain: Some of the second generation drugs are thought to affect people’s sense of having had enough to eat. They can also be sedating. These two effects can result in weight gain, which can increase a person’s risk of diabetes and heart disease.
  • Diabetes: Schizophrenia is a risk factor for diabetes. Antipsychotic drugs can increase this risk.
  • Agitation and sedation: Some people feel “wired” and unable to stop moving when taking antipsychotics. This effect may be mistaken for a worsening of illness rather than a side-effect of the medication. These same drugs can also have the opposite effect, making people feel tired. Some people may feel either wired or tired, and some may feel both at the same time.
  • Tardive dyskinesia: For every year that a person takes antipsychotic medication, there is a five per cent chance of developing tardive dyskinesia (TD), a condition that causes people to have repetitive involuntary movements. The risk of TD is highest with the first generation antipsychotics, although it can occur with the second generation drugs. TD can worsen when you stop taking medication and can be permanent .
  • Neuroleptic malignant syndrome: This rare but serious complication is usually associated with the use of high doses of typical antipsychotics early in treatment. Signs include fever, muscle stiffness and delirium.

Side-effects vary depending on the type of medication. More information on side-effects is included with each type of antipsychotic.


Controlling the side-effects of antipsychotics

You can help to control possible side-effects on your own by:

  • getting regular exercise and eating a low-fat, low-sugar, high-fibre diet (e.g., bran, fruits and vegetables) to reduce the risk of diabetes and help prevent weight gain and constipation
  • using sugarless candy or gum, drinking water, and brushing your teeth regularly to increase salivation and ease dry mouth
  • getting up slowly from a sitting or lying position to help prevent dizziness.

Types of Antipsychotic Medications

NOTE: medications are referred to in two ways: by their generic name and by their brand or trade names. Brand names available in Canada appear in brackets.


Antipsychotic medications are generally divided into two categories:
  • atypical (second generation) antipsychotics
  • typical (first generation) antipsychotics

The main difference between the two types of antipsychotics is that the first generation drugs block dopamine and the second generation drugs block dopamine and also affect serotonin levels. Evidence suggests that some of the second generation drugs have milder movement-related side-effects than the first generation drugs.

Both categories of drugs work equally well overall, although no drug or type of drug works equally well for everyone who takes it. When the same drug is given to a group of people, one-third of that group will find that it works well; another third will find that the drug helps only with some symptoms; and the final third will find that it does not help at all. For this reason, people may need to try different antipsychotics before finding the one that works best for them.

Most of these drugs are given in tablet form, some are liquids and others are given as injections. Some are available as long-lasting (depot) injections, which may be given anywhere from once a week to once a month.

Most people who take antipsychotics over a longer term are now prescribed the second generation (also called atypical) drugs.


Atypical antipsychotics

The second generation antipsychotics are usually the first choice for the treatment of schizophrenia. Although they may not be officially approved for these other uses, they are sometimes used in the treatment of mood and anxiety disorders, such as bipolar, posttraumatic stress and obsessive-compulsive disorders.

Medications available in this class include risperidone (Risperdal), quetiapine (Seroquel), olanzapine (Zyprexa), ziprasidone (Zeldox), paliperidone (Invega), aripiprazole (Abilify) and clozapine (Clozaril).

Clozapine is exceptional in that it often works even when other medications have failed; however, because it requires monitoring of white blood cell counts, it is not the first choice for treatment.

Possible side-effects of atypical antipsychotics include: 

The following list details other side-effects of atypical antipsychotics and which drugs are most likely to least likely to have these effects.

Weight gain, diabetes: clozapine > olanzapine > quetiapine > risperidone > ziprasidone, aripiprazole

Movement effects (e.g., tremor, stiffness, agitation): risperidone > olanzapine, quetiapine, ziprasidone, aripiprazole > clozapine

Sedation (e.g., sleepiness, low energy): clozapine, olanzapine and quetiapine > risperidone, ziprasidone, aripiprazole

Decreased sex drive and function, missed periods, discharge from breast: risperidone > olanzapine, quetiapine > clozapine, ziprasidone


Typical (first generation) antipsychotics

These older medications include chlorpromazine (once marketed as Largactil), flupenthixol (Fluanxol), afluphenazine (Modecate), haloperidol (Haldol), loxapine (Loxapac), perphenazine (Trilafon), pimozide (Orap), trifluoperazine (Stelazine), thiothixene (Navane) and zuclopenthixol (Clopixol).

Side-effects of typical antipsychotics vary depending on the drug and may include drowsiness, agitation, dry mouth, constipation, blurred vision, emotional blunting, dizziness, stuffy nose, weight gain, breast tenderness, liquid discharge from breasts, missed periods, muscle stiffness or spasms. 

Frequently Asked Questions

How long should I take antipsychotics?

If you take antipsychotics for psychosis, how long you take them depends on what the psychosis is related to and how many episodes you have experienced. In some situations, you may only need to take this medication until the symptoms of psychosis are relieved. In others, antipsychotics may be used over a longer term to help prevent further episodes.

When starting a new antipsychotic as a long-term treatment, you should take that drug for at least a month before deciding whether or not it is working for you.

Are antipsychotics addictive?

Drugs that are addictive produce a feeling of euphoria, a strong desire to continue using the drug, and a need to increase the amount used to achieve the same effect. Antipsychotics do not have these effects.

Antipsychotics do, however, have one thing in common with some addictive drugs—they can cause withdrawal effects when you stop taking them, especially if you stop suddenly. These effects can include nausea, vomiting, diarrhea and stomach pain, dizziness and shakiness. When the time comes to cut down or stop taking the drug, cutting back gradually helps to reduce withdrawal effects.

How do I cut down or stop taking antipsychotics?

Whether you want to cut down your dose or stop taking a medication, the same rule applies: go slowly. A sudden change in your dose greatly increases the risk that psychotic symptoms will return or become more intense.

The first step is to ask yourself if this is the right time. Are you feeling well? Is the level of stress in your life manageable? Do you feel supported by your family and friends?

If you think you’re ready, talk to your doctor. If your doctor doesn’t agree, find out why. If you are not satisfied with his or her reasons, you may want to see another doctor for a second opinion.

If your doctor does agree, he or she will advise you not to skip doses but to reduce your dose gradually—usually by about 10 per cent at a time—with at least two to three weeks between each reduction. This process of cutting back will take several months. Using a pill cutter or a liquid form of your medication can help you to cut your dose down in small amounts.

If you want to stop taking more than one medication, your doctor will usually suggest that you lower the dose of one drug at a time.

If you start to feel unwell as you cut down, let your doctor know. He or she can help you determine whether you are experiencing withdrawal effects or signs that symptoms are returning. You may want to go back up with your dose. Find the dose that works best for you.

Will antipsychotics interact with other medications?

Antipsychotics may interact with other medications prescribed by your doctor or dentist or purchased at a drug store, and with herbal remedies or street drugs. Make sure you tell your doctor about all drugs you are taking.

Always ask your doctor or pharmacist about potential interactions before taking any medications or herbal remedies, including cold or allergy tablets or cough syrups.

Antacids can interfere with absorption of antipsychotics and decrease their effect. If you are taking antacids, you can avoid this by taking them at least two hours before or one hour after taking your medication.

What if I smoke cigarettes or drink coffee or alcohol while taking antipsychotics?

Smoking cigarettes can increase how quickly some antipsychotics are broken down by the body, meaning that people who smoke heavily may need more medication than those who do not. Drinking coffee has the opposite effect, slowing down the breakdown of antipsychotics. If you change how many cigarettes you smoke or how much coffee you drink, let your doctor know as he or she may need to adjust your dose.

Antipsychotic drugs may increase the effects of alcohol, making you more sleepy, dizzy and lightheaded. Having one or two drinks on occasion should be okay—but remember that one drink may have the effect of two or even three drinks.

Smoking and problems with alcohol are more common among people with schizophrenia than they are in the general population. The reason for this is unclear; what is clear is that smoking reduces life expectancy, and alcohol can make it even more challenging to manage the symptoms of schizophrenia. Being open and honest about your smoking and drinking lets your doctor know how you are doing and helps him or her to determine whether your medication needs to be adjusted. Talking to your doctor can also give you a chance to think about whether you want to cut down or stop smoking or drinking.

What if I use street drugs while taking antipsychotics?

Some street drugs, such as marijuana, cocaine and amphetamines, may have effects that feel good in the short term, but they can cause symptoms to return or worsen. Using these drugs increases the risk of psychosis, even in people who do not have schizophrenia or another mental health problem. Street drugs may also interfere with your medication or worsen side-effects.

Will taking antipsychotics affect my ability to drive safely?

Antipsychotic drugs can be sedating, so it’s a good idea not to drive or operate other machinery until you know how the medication affects you.

Will taking antipsychotics affect my sex drive and function?

People who take antipsychotics can experience decreased sex drive or even problems in sexual functioning. Men may have difficulty getting or keeping an erection or ejaculating. Women may be unable to have an orgasm. Let your doctor know if you experience these side-effects. Often an adjustment in dose or change of medication can help.

These drugs can also cause irregular periods and false-positive pregnancy results in women.

Is it safe to take antipsychotics while pregnant or breastfeeding?

Each woman’s situation is unique and should be discussed with her doctor. For any pregnant woman with a history of psychosis, the question of taking antipsychotics during pregnancy usually comes down to a risk-benefit analysis. Psychosis can affect prenatal care and a mother’s ability to parent her newborn child. When treatment with an antipsychotic helps to avoid a relapse or to reduce distress, the benefits of continuing the medication may outweigh the risks.

Antipsychotics are relatively safe to use during pregnancy and while breastfeeding. If used in high doses close to delivery, the baby may be born with temporary breathing difficulties and/or withdrawal symptoms (e.g., restlessness, feeding problems). Antipsychotic medications pass into breast milk and, depending on the dose, may cause drowsiness in the baby. There are ways, however, to minimize and manage the short-term symptoms that may occur. Your doctor can help you to choose the safest type of medication to take during pregnancy and breastfeeding, and to find a dose that will provide the maximum benefits with the minimum risk.

If you decide to stop taking medications during pregnancy or while breastfeeding, it is a good idea to see your doctor more often to help you monitor for a return of symptoms.

Is age an issue when taking antipsychotic medications?

The effectiveness and risks of antipsychotic medication can vary depending on the age of the person taking it.

Can children and teens use antipsychotics?

Antipsychotics can be used to treat children and teens with severe psychiatric disorders such as psychosis, bipolar disorder, Tourette syndrome, autism or severe aggression. Most often, psychotherapy also has an important role. Children and teens are more likely than adults to experience side-effects from these medications, especially the second generation (atypical) antipsychotics.

Can older adults use antipsychotics?

As people age into their 60s and older, they become more sensitive to medication and may require a lower dose. Being more sensitive also means that older people are more likely to experience side-effects than when they were younger. They are also more likely to have other medical problems and to be taking other medications, which could interact with antipsychotic drugs. Antipsychotics can increase the risk of falls, especially when taken with other drugs.

Tardive dyskinesia and other movement-related side-effects can develop in older adults who have used antipsychotics over a long period. Women are twice as likely as men to experience these effects.

Antipsychotic medications are sometimes used to calm older adults with psychosis related to dementia. However, use of antipsychotics by older adults has been associated with an increased risk of stroke. Other ways of calming the person should always be tried first, and when antipsychotics are needed, they should only be used until symptoms are relieved.

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