Potential Side Effects of Haldol (Haloperidol)

many rubbing his eyes as a medication side effect
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Haldol—generic name haloperidol—is a typical antipsychotic drug effectively used in the management of mania, agitation, and psychosis in various mental illnesses, including bipolar disorder. While Haldol can be an effective treatment, it also carries the risk of significant side effects. A patient taking Haldol or haloperidol should be aware of the potential side effects, some of which are medical emergencies.

Haloperidol Side Effects

Unfortunately, all of 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.

Haldol side effects may range from mild to severe, with some side effects requiring immediate medical attention. It's essential that you let your doctor know if you have any physical changes which concern you while taking the medication.

Mild Side Effects

There are several less serious side effects that people may experience while using Haldol. Though these are not an emergency or don't usually mean that you need to stop the medication, talk to your doctor if you find them bothersome. There are sometimes measures you can take to either cope with these side effects or help them to go away, for example, by using sunscreen when you are out of doors.

More common mild side effects include:

  • Blurred vision
  • Breast swelling or pain in women
  • Changes in menstrual period
  • Constipation
  • Mouth dryness
  • Unusual secretion of milk from breasts
  • Weight gain

Less common mild side effects include:

  • Decreased sexual ability
  • Drowsiness
  • Increased sun sensitivity (involving skin rash, itching, redness or other skin discoloration, or severe sunburn)
  • Nausea or vomiting

Potentially Serious Side Effects

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

More common serious side effects include:

  • 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

Less common serious side effects include:

  • 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

Rare but serious side effects:

  • 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 Haldol, that while uncommon, are potentially extremely serious. If you note any of these side effects, stop taking your Haldol 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 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

Tardive Dyskinesia With Haldol

Haldol 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 is far too common with long-term use. Approximately 24% to 32% of people taking this medication might develop some degree of tardive dyskinesia.

Research shows that other drugs for bipolar disorder may not have as great a risk of tardive dyskinesia as Haldol. However, they do carry their own risks. If you're concerned about your risk, talk to your doctor about your medication options.

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 Haldol, 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.​

Overdose and Discontinuation

When you're discontinuing Haldol, 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.

Symptoms of a Haldol overdose include severe breathing difficulty; severe dizziness; severe drowsiness; severe muscle trembling, jerking, stiffness or uncontrolled movements; and severe, unusual tiredness or weakness. If you experience these symptoms, seek emergency medical assistance.

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Article Sources
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  1. U.S. Food & Drug Administration. Haldol. Updated December 2017.

  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

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