Potential Side Effects of Haloperidol (Haldol)

many rubbing his eyes as a medication side effect

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Haldol (haloperidol) is a typical antipsychotic drug used to treat schizophrenia and schizoaffective disorder, psychosis, agitation, and acute manic episodes associated with bipolar disorder. Haloperidol can also treat motor and verbal tics in those with Tourette syndrome.

Once your symptoms have been eased by taking tablets, you may decide to take long-acting injections to keep your symptoms at bay. The injection is typically given every three to four weeks and slowly releases haloperidol into your body.

While haloperidol can be an effective treatment, it also carries the risk of significant side effects. If you or your loved one is taking haloperidol you should be aware of these potential side effects, some of which are medical emergencies.

Common Side Effects

Unfortunately, all the drugs used to treat psychosis carry some risk for side effects. Choosing a medication to treat psychosis is often a process of choosing which side effects you are most able to tolerate.

Most of the side effects of haloperidol are mild and well-tolerated. They include:

  • Blurred vision
  • Breast swelling or pain in women
  • Changes in menstrual period
  • Constipation
  • Mouth dryness
  • Unusual secretion of milk from breasts
  • Weight gain
  • Decreased sexual ability
  • Drowsiness
  • Increased sun sensitivity (involving skin rash, itching, redness or other skin discoloration, or severe sunburn)
  • Nausea or vomiting

Side effects usually improve as your body adjusts to the new medicine. Let your doctor know if your side effects don't go away or become particularly bothersome. They may be able to adjust the dose and minimize these effects.

Serious Side Effects of Haloperidol

Some of the following side effects may be less serious, but should prompt you to call your doctor as soon as possible:

  • Difficulty in speaking or swallowing
  • Inability to move eyes
  • Loss of balance control
  • Mask-like face
  • Muscle spasms, especially in the neck and back
  • Severe restlessness or need to keep moving
  • Shuffling walk
  • Stiffness of arms and legs
  • Trembling and shaking of fingers and hands
  • Twisting body movements
  • Weakness of arms and legs
  • Decreased thirst
  • Difficulty urinating
  • Dizziness, lightheadedness, or fainting
  • Hallucinations
  • Lip-smacking or puckering
  • Puffing of cheeks
  • Rapid or worm-like tongue movements
  • Skin rash
  • Uncontrolled arm and leg movements
  • Uncontrolled chewing movements
  • Confusion
  • Hot, dry skin, or lack of sweating
  • Increased blinking or eyelid spasms
  • Muscle weakness
  • Sore throat and fever
  • Uncontrolled twisting movements of neck, trunk, arms, or legs
  • Unusual bleeding or bruising
  • Unusual facial expressions or body positions
  • Yellow eyes or skin (jaundice)

Emergency Side Effects

There are some side effects of that while uncommon, are potentially extremely serious. If you note any of these side effects, stop taking haloperidol and seek help immediately. In the case of some of these side effects, such as seizures, you may be unable to call yourself.

Make sure that your friends and loved ones know about these possible side effects and to call for help if they should see you experiencing any of them.

Potential emergency side effects include:

  • Convulsions (seizures from neuroleptic malignant syndrome)
  • Difficult or fast breathing
  • Fast heartbeat or irregular pulse
  • High fever
  • Increased sweating
  • Low blood pressure
  • Severe muscle stiffness
  • Unusually pale skin

Allergic Reactions

Tardive Dyskinesia

Haloperidol can cause a movement disorder called tardive dyskinesia. This disorder is thought to occur due to an increased brain sensitivity to the neurotransmitter dopamine. Signs of tardive dyskinesia include fine, worm-like movements of the tongue, or other uncontrolled movements of the mouth, tongue, cheeks, jaw, or arms and legs. These symptoms may not go away after you stop taking the drug.

Unfortunately, this side effect common with long-term use. Approximately 24% to 32% of people taking this medication might develop some degree of tardive dyskinesia.

You may wish to go over the alternative medications that are available and determine which ones have a side effect profile that you find would be more tolerable for you.

For those who need to take haloperidol, research is in progress looking at methods of decreasing the risk of tardive dyskinesia. Many of the studies, such as those looking at antioxidants such as Ginkgo biloba or alpha-tocopherol (a type of vitamin E), have only been done on animals in the lab. Before starting the medication, talk to your doctor about any options she feels may decrease your risk.​

Taking Haloperidol Safely

Use as Directed

Haloperidol tablets and solution are usually taken one or two times per day.

Precautions

Interactions

Black Box Warning

Older patients (aged 65 and older) with dementia related psychosis are at increased risk for death when taking Haldol. The U.S. Food and Drug Administration (FDA) labeled all antipsychotics with a "black box" warning about this risk and a reminder that they are not approved to treat dementia symptoms. A black box warning is the most serious warning given by the FDA.

Side Effects of Withdrawal

When you're discontinuing haloperidol, you may experience trembling in your fingers and hands, along with uncontrolled movements of your mouth, tongue, and jaw. If you do have these side effects, notify your doctor as soon as possible.

Signs of Overdose

Symptoms of a haloperidol overdose include:

  • Jerking
  • Severe breathing difficulty
  • Severe dizziness
  • Severe drowsiness
  • Severe muscle trembling
  • Severe, unusual tiredness, or weakness
  • Stiffness or uncontrolled movements

If you experience these symptoms, seek emergency medical assistance.

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4 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Food & Drug Administration. Haldol label.

  2. Seigneurie AS, Sauvanaud F, Limosin F. Prevention and treatment of tardive dyskinesia caused by antipsychotic drugs. Encephale. 2016;42(3):248-254. doi:10.1016/j.encep.2015.12.021

  3. Shi J, Tan YL, Wang ZR, et al. Ginkgo biloba and vitamin E ameliorate haloperidol-induced vacuous chewingmovement and brain-derived neurotrophic factor expression in a rat tardive dyskinesia model. Pharmacol Biochem Behav. 2016;148:53-58. doi:10.1016/j.pbb.2016.06.003

  4. Meeks TW, Jeste DV. Beyond the black box: What is the role for antipsychotics in dementia?Curr Psychiatr. 2008;7(6):50-65. PMID: 19221607

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