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.
Schizophrenia
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).
Source:Â DailyMed
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):
Typically given monthly
Low risk for weight gain, compared to some other antipsychotics
Available as a lower-cost, generic medication
Needs to be injected
Higher risk of movement-related side effects compared to atypical antipsychotics
Can't be used in children
Haloperidol injection can make you sleepy. Don't drive or do anything requiring concentration until you know how this medication affects you.
Avoid drinking alcohol while taking haloperidol injection because it can make you sleepier, drop your blood pressure, and raise your risk of accidental injuries.
It might take some time before you find the dose that works best for you. Don't stop taking haloperidol injections without talking to your provider first, even if you don't feel better.
Taking haloperidol injection can make you more sensitive to certain medications, such as barbiturates (e.g., phenobarbital), sedatives, opioid pain medications (e.g., morphine, oxycodone / acetaminophen (Percocet), hydrocodone / acetaminophen (Norco)), and antihistamines (e.g., diphenhydramine (Benadryl)). Taking haloperidol injection with these medications can raise your risk of side effects. Let your provider know about all the medications you're taking before starting haloperidol injection. Don't start any new medications without talking to your provider or pharmacist first.
There have been reports of people feeling weakness, fever, confusion, and uncontrollable muscle contractions and movements when taking lithium (Lithobid) and haloperidol injection together. Let your provider know if you're taking lithium and if you get any of these side effects while taking both medications.
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.
Risk factors: Age 65 and older with dementia and psychosis
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.
Risk factors: Low potassium or magnesium blood levels | Older age | Using other medications that cause QT prolongation | Born with QT prolongation | Hypothyroidism (low thyroid hormone) | History of heart problems or abnormal heart rhythms (arrhythmias) | Slow heart rate
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.
Risk factors: Taking other antipsychotic medications | Older age | Female sex | High dose | Taking haloperidol injection for a long period of time | Parkinson's disease | Lewy body dementia
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.
Risk factors: Taking antipsychotic medications
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.
Risk factors: Low blood pressure | Taking medications that lower blood pressure | History of medical conditions that can lower blood pressure
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.
Risk factors: Older age | Breathing problems | Smoker
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.
Risk factors: History of low blood cell counts
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.
Your provider will determine your dose of haloperidol injection based on different factors, such as what dose of oral haloperidol you've been taking, your age, and your symptoms. This medication is injected into the muscle and typically given once a month by a healthcare provider in a clinic setting.
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.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Any condition where there's a slowdown of brain activity that leads to symptoms such slowed breathing, slurred speech, slowed reflexes, and confusion
Schizophrenia in adults and children age 13 years and older
Bipolar disorder in adults and children age 10 years and older
Add-on to antidepressants for depression (extended-release only)
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