Pimozide, commonly known as Orap, is a first-generation antipsychotic medication, primarily used in the treatment of Tourette’s disorder. It is important to take this medication exactly as prescribed and consult with your doctor before starting any other medication (prescribed or over the counter) while on pimozide, as adverse effects can occur.

Pimozide brand names

  • Orap

What is pimozide prescribed for?

Orap is approved by the US Food and Drug Administration (FDA) for use in the treatment of Tourette’s disorder. It is typically not prescribed to children under the age of 12, as the safety and effectiveness of the medication in this age group is not known, although it can be prescribed if deemed necessary by a medical professional [1].

Pimozide is prescribed to those who experience motor and phonetic tics that cause a severe impairment in daily function or development. It is not advised for use in treating mild symptoms and should only be prescribed if alternative/standard treatments have been unsuccessful [2].

Orap has historically been used in the treatment of schizophrenia and may still be prescribed for this condition, although newer medications, such as second-generation (atypical) antipsychotics are generally preferred by physicians, due to the decreased risk of serious side effects [3].

How does pimozide work?

Pimozide works by decreasing the activity in the brain of the neurotransmitter, dopamine. This is believed to be the mechanism that helps to alleviate symptoms of Tourette’s disorder, including motor and phonetic tics, as well as symptoms of schizophrenia and psychosis [4].

How is pimozide usually taken?

Pimozide is available as a 1mg and 2mg tablet, which should be swallowed whole without crushing.

For the treatment of Tourette’s disorder in children and adolescents, the dose is weight dependent and will likely start at 0.05mg per kg. This can then be gradually increased to a daily dose of 0.2mg per kg, up to a maximum of 10mg per day.

For adults, your doctor will likely prescribe an initial dose of 1-2mg per day, to be taken in divided doses. This can then be gradually increased up to a maximum of 10mg per day, depending on your weight [1].

A daily dose of over 10mg is not recommended, due to the increased risk of serious side effects, especially impacts on the heart.

For the maintenance treatment of schizophrenia, pimozide is usually prescribed at 4-6mg per day [5].

Throughout your treatment, your doctor will closely monitor your physical health to ensure your safety, as well as monitoring any changes or improvements in the symptoms of your condition. They will aim to prescribe you the lowest possible dose that is effective at treating your symptoms, to prevent adverse effects from the medication [1].

This medication should be taken as prescribed, without missing a dose. If a dose is missed, take the medication as soon as possible, or if it is close to the next dosage time, skip the missed dose. Never take double your prescribed dose in one go, as this can have adverse effects and may increase the risk of side effects.

How long does pimozide stay in your system?

When you start taking pimozide, the medication will begin working within 1-2 weeks, but it will likely take several weeks before it takes full effect [1], so it is important to continue taking it exactly as your doctor prescribes, in order to experience the benefit.

After you stop taking pimozide, the effects of the medication will wear off after 1-2 days, but it can take several weeks for the medication to entirely leave your system [5].

Do not suddenly stop taking pimozide, even if you feel better, as this can have serious impacts on your mental and physical health and may worsen your condition. If your doctor advises that it is safe to come off this medication, they will likely reduce your prescription slowly, to prevent adverse effects.

Pimozide side effects

When you begin a new medication, you may experience some common side effects. They will likely reduce within the first week or two, but if they continue or become problematic, consult with your doctor immediately, as you may need a reduced dose or a change of medication.

Common side effects of pimozide include:

  • Diarrhea or constipation
  • Feeling dizzy, unsteady, unable to hold yourself up properly
  • Dry mouth or increased saliva
  • Change in appetite and weight
  • Changes in vision
  • Restlessness or heightened heartrate
  • Unusual, slower movements, or a shuffling walk
  • Sexual dysfunction
  • Rash
  • Headaches or migraines
  • Generaly changes in behavior

Serious side effects of pimozide are less common but may still occur. Contact your doctor immediately if you experience any of the following:

  • Fever and sweating
  • Muscle pain or stiffness
  • Irregular heartbeat
  • Difficulty breathing or swallowing
  • Falling or collapsing
  • Confusion
  • Cramping in the neck
  • Tightness in the throat or sore throat
  • Uncontrollable movements in the face, mouth, or tongue, including lip smacking and chewing

Pimozide precautions

It is important that your doctor is aware of any past or present mental illness you have experienced, to enable safe monitoring of your condition while on this medication, or to decide if it is safe for you.

Discuss with your doctor all your past and present physical health conditions, as they may impact your ability to take this medication safely.

Because of the potential for heart-related side effects, this medication may not be appropriate if you have experienced any serious heart conditions, a history of high blood pressure, or you are taking certain heart-related medications [1].

Ensure you tell your doctor if you have had any liver, kidney, or brain issues, breast cancer, Parkinson’s disease, glaucoma, or seizures, as it may not be safe for you to take this medication, or your doctor may wish to prescribe you a lower dose and closely monitor your physical health throughout your treatment.

Pimozide can cause neuroleptic malignant syndrome, which is a potentially fatal movement disorder [6]. As such, it is important to attend all appointments with your doctor so that they can monitor your physical health carefully and you can inform them of any concerning side effects that you experience.

Ensure you tell your doctor if you are pregnant or planning to become pregnant while taking pimozide, as this medication can cause harm to the fetus. As such, pimozide should only be used while pregnant if the benefits of the treatment outweigh any potential risks to the baby.

Tell your healthcare professional if you are breastfeeding. Although the risk of breastfeeding while on pimozide is not currently clear, many medications can pass to babies through breast milk, so there may be a risk of heart-related effects [1]. As such, it may be advised to either stop taking the medication or stop breastfeeding, depending on the mother’s requirement for the medication.

This medication can cause drowsiness and sedation, so it is important to avoid driving until you are aware of how pimozide affects you and it is safe to do so.

Pimozide can cause dizziness, so it is advised to get up slowly from sitting or lying down, to prevent the risk of falls.

Pimozide interactions

Pimozide should not be taken alongside antidepressant medications known as selective serotonin reuptake inhibitors (SSRIs), such as sertraline and citalopram, as this can cause serious and potentially fatal effects [1].

Pimozide should not be prescribed for people taking a medication that can cause tics, such as methylphenidate (Concerta and Ritalin). These medications should first be stopped, to determine whether they are the cause of the tics, or to determine a diagnosis of Tourette’s disorder.

Some medications may interact with clomipramine, causing a decrease in the effectiveness of your medication, or an increase in the risk of side effects. This includes some antibiotic, antifungal, and antiviral medications, opioids, heart medications, diuretics, seizure medications, sedatives, tranquilizers, and anti-anxiety medications [2]. Some of these medications can interact with pimozide to cause heart issues, while other medications on this list can make pimozide too effective or not effective enough.

Always discuss your medications with your doctor before starting a new treatment.

It is advised not to eat or drink grapefruit while on pimozide, as grapefruit juice can impact the levels of the medication in the body.

It is advised to avoid or limit alcohol while on pimozide, as alcohol can increase feelings of drowsiness caused by the medication.

Pimozide storage

Always keep all medications out of reach of children.

Store clomipramine in its original packaging, in airtight containers, and at room temperature (never above 86°F).

If you need to dispose of medication that is out of date or no longer needed, contact a medical professional to ensure it is disposed of appropriately. Never flush medications down the toilet or put them in the bin, as this can create unnecessary risks.

What to do if you overdose on pimozide

If you overdose on pimozide, call a medical professional, or Poison Control on 1-800-222-1222, or in case of an emergency, call 911 for urgent medical attention. Symptoms of a pimozide overdose include uncontrollable or unusual movements, shuffling walk, restlessness, fast heartbeat, breathing difficulties, and coma.

Frequently asked questions about pimozide

Can pimozide help anxiety?

Antipsychotic drugs are not typically prescribed to treat anxiety. First-line treatments include antidepressants known as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), and a short-term treatment of benzodiazepines [7].

Occasionally, atypical (second-generation) antipsychotic drugs are used to treat certain anxiety disorders but are not a preferred treatment due to the potential for side effects [8]. Pimozide has not been found to be useful in treating anxiety [5].

Is pimozide addictive?

Pimozide is not an addictive substance but can cause withdrawal symptoms after the medication is stopped, depending on the dosage and length of treatment. As such, your doctor will likely reduce your daily dosage slowly, to prevent withdrawal symptoms.

Does pimozide cause weight gain?

Most antipsychotic drugs are known to be associated with weight gain as a side effect. However, pimozide typically does not cause weight gain and has been found to occasionally cause weight loss [9].

Can you drink alcohol with pimozide?

It is advised to avoid or limit alcohol intake while on pimozide, as alcohol can increase drowsiness caused by the medication and lead to an increased risk of falls or breathing difficulties.

Resources:

  1. Teva Pharmaceuticals USA. (Revised 2008). ORAP (Pimozide) Tablets. Access Data FDA. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2009/017473s041lbl.pdf
  2. American Society of Health-System Pharmacists, Inc. (Revised 2017). Pimozide. MedlinePlus. Retrieved from https://medlineplus.gov/druginfo/meds/a686018.html
  3. Tueth, M.J., & Cheong, J.A. (1993). Clinical Uses of Pimozide. Southern Medical Journal, 86(3), 344–349. Retrieved from https://doi.org/10.1097/00007611-199303000-00019
  4. National Center for Biotechnology Information (2022). PubChem Compound Summary for CID 16362, Pimozide. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Pimozide
  5. Pinder, R.M., Brogden, R.N., Swayer, R., Speight, T.M., Spencer, R., & Avery, G.S. (1976). Pimozide: A Review of its Pharmacological Properties and Therapeutic Uses in Psychiatry. Drugs, 12(1), 1–40. Retrieved from https://doi.org/10.2165/00003495-197612010-00001
  6. Berman B.D. (2011). Neuroleptic Malignant Syndrome: A Review for Neurohospitalists. The Neurohospitalist, 1(1), 41–47. Retrieved from https://doi.org/10.1177/1941875210386491
  7. Bandelow, B., Michaelis, S., & Wedekind, D. (2017). Treatment of Anxiety Disorders. Dialogues in Clinical Neuroscience, 19(2), 93–107. Retrieved from https://doi.org/10.31887/DCNS.2017.19.2/bbandelow
  8. Hershenberg, R., Gros, D.F., & Brawman-Mintzer, O. (2014). Role of Atypical Antipsychotics in the Treatment of Generalized Anxiety Disorder. CNS Drugs, 28(6), 519–533. Retrieved from https://doi.org/10.1007/s40263-014-0162-6
  9. Allison, D.B., Mentore, J.L., Heo, M., Chandler, L.P., Cappelleri, J.C., Infante, M.C., & Weiden, P.J. (1999). Antipsychotic-Induced Weight Gain: A Comprehensive Research Synthesis. The American Journal of Psychiatry, 156(11), 1686-1696. Retrieved from https://doi.org/10.1176/ajp.156.11.1686