Haloperidol injection is an antipsychotic medication that's used to treat schizophrenia. It's a long-acting injection that's given into the muscles monthly by a healthcare provider. It's also available as a shorter-acting injection that's typically given in a hospital setting to people who are experiencing agitation related to schizophrenia. The most common side effects of haloperidol injection are movement-related side effects, such as rigid muscles, tremors, and trouble speaking.
Haloperidol injection is a typical antipsychotic. It works by blocking the activity of dopamine, a chemical involved with mood and movement, in your brain. This leads to lower dopamine levels, which causes less hallucinations (seeing things that aren't there) and delusions (beliefs in things that aren't true).
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Contact your healthcare provider immediately if you experience any of the following.
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Because haloperidol injection is slowly released in your body, it can take a few weeks before you notice the benefits of this medication. If you and your provider are considering haloperidol injection as a possible treatment, your provider will probably have you try oral haloperidol tablets first. This is so that you know how haloperidol affects you and whether or not you can tolerate its side effects before you start receiving the longer-acting injection. Once you start receiving haloperidol injection, your provider might have you continue taking haloperidol tablets for a few weeks until the effects of the haloperidol injection kicks in.
Typically, you'll need to receive haloperidol injections monthly in order for the levels of this medication to remain stable in your body.
The long-acting haloperidol injection (haldoperidol decanoate) is unlikely to cause sleepiness. But people who've received the short-acting haloperidol injection have reported sleepiness and sedation. If you're starting haloperidol injection for the first time, don't drive or doing any activities that require you to be alert until you know how this medication affects you.
While possible, it's unlikely for you to experience weight gain from haloperidol injection. You're less likely to gain weight from haloperidol injection compared to from some other antipsychotics, such as olanzapine (Zyprexa) or quetiapine (Seroquel). To minimize your risk for weight gain while taking haloperidol injection, make sure to have a healthy diet and regular exercise routine.
Yes, haloperidol is available as tablets and a solution that you can take by mouth. One difference between haloperidol injection and oral haloperidol is how often you need to take your dose. You'll need to receive a haloperidol injection monthly for it to best control your symptoms. But you need to take the haloperidol tablets or solution every day in order for the medication to work. Speak with your provider about which form of haloperidol is best for you.
There isn't enough information available to know if haloperidol injection is safe to take during pregnancy or while breastfeeding. Studies do show that babies born to mothers who received haloperidol in the third trimester of pregnancy can experience withdrawal symptoms, such as agitation, trouble breathing, poor feeding, right after birth. If you're pregnant or thinking of becoming pregnant, talk to your provider to discuss the risks and benefits of taking haloperidol injection.
Haloperidol injection isn't FDA-approved to be given as an IV injection. It's only given as an injection into the muscles. But research shows that healthcare providers sometimes give the fast-acting haloperidol injection through the veins in the hospital setting.
Haloperidol injection can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
People 65 years and older with dementia sometimes have delusions and hallucinations (believing, seeing, or hearing things that aren't real). This is called dementia-related psychosis. Older people with dementia-related psychosis have a higher risk of death if they take medications like haloperidol injection. Because of this risk, haloperidol injection shouldn't be used in people 65 years and older with dementia-related psychosis. Let your provider know if you or someone you know has dementia before starting haloperidol injection.
In addition, older patients with dementia-related psychosis treated with some antipsychotics had a higher risk of stroke. Seek medical help immediately if you experience sudden numbness in your face, arms, or legs (especially on one side of your body), or if you have sudden trouble speaking, seeing, walking, or understanding people.
Although rare, haloperidol injection can affect your heart rhythm by prolonging the time period from when the heart pumps and then relaxes. This is known as QT prolongation and it can be life-threatening. Your risk for QT prolongation is higher if you have any of the risk factors listed above. Depending on your risks for QT prolongation, your provider might check your heart rhythm from time to time with an electrocardiogram (EKG). Make sure to tell your provider about all the medications you're taking and don't start any new medications while taking haloperidol injection without talking to your provider or pharmacist first. People who were born with QT prolongation or have a history of arrhythmias should avoid taking haloperidol injection. If you feel your chest pounding, have trouble breathing, chest pain, or feel lightheaded while taking haloperidol injection, call 911 right away.
Antipsychotic medications like haloperidol injection can cause uncontrolled body movements, such as eye-twitching or lip-smacking. Your risk of this happening is more likely the longer you take medications like haloperidol injection and if you're taking a higher dose. If you have Parkinson's disease or certain types of dementia, your risk is higher and you shouldn't take haloperidol injection. These movement problems can become permanent. If you experience any uncontrolled movements and aren't able to stop them, talk to your provider right away.
Taking antipsychotic medications like haloperidol injection can cause a rare, but life-threatening condition called neuroleptic malignant syndrome (NMS). Symptoms include fever, sweating, stiff muscles, confusion, not aware of your surroundings, and fast or irregular heartbeat. If you experience any of these symptoms while taking haloperidol injection, seek medication attention as soon as possible. Your provider will likely have you stop taking haloperidol injection and switch you to something else.
Haloperidol injection can make you tired, lower your blood pressure, or cause you to lose your balance, which can lead to falls and injuries. When standing from a sitting or lying position, make sure to get up slowly and hold onto something. If you have concerns, speak to your provider.
Some cases of bronchopneumonia, a type of infection in your lungs where your lungs get inflamed, have been reported after using antipsychotics like haloperidol injection. Your risk is higher if you're older in age, smoke, or have breathing problems. Seek medical attention immediately if you experience a fever, cough, or trouble breathing.
Though not common, haloperidol injection can lower your white blood cell counts, especially if they've been low previously from other conditions. This can raise your risk of serious infection. You'll need to get blood tests done regularly during the first few months of taking haloperidol injection so your provider can make sure your blood cell counts are in the normal range. If your blood counts drop too low, you'll likely need to stop taking haloperidol injections. If you develop any signs of infection, such as fever, tiredness, chills, cough, or trouble breathing, and they don't go away, contact your provider right away.
Haloperidol injection should only be used in pregnancy if the benefits outweigh the potential risks to your unborn baby. Newborn babies exposed to haloperidol during the third trimester of pregnancy are at a higher risk for side effects and withdrawal symptoms following delivery. Let your healthcare provider know if you're pregnant or plan to become pregnant while taking haloperidol injection.
Haloperidol is also available as a quick-acting injection to treat agitation from schizophrenia that's given into the muscles by a healthcare provider in a hospital setting.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Haloperidol injection will not be safe for you to take.