Haloperidol (Intramuscular)


Used to treat a variety of psychiatric disorders, Haloperidol is available in various forms. As well as being taken orally or delivered intravenously, the medication can be administered via an intramuscular injection. This type of medication is most suited to patients who are unable or unwilling to take oral medication on a regular basis.

Often prescribed to treat schizophrenia, Haloperidol can also be used to reduce the frequency of tics in patients with Tourette's syndrome. In addition to this, Haloperidol is prescribed to treat mania caused by bipolar disorder, acute psychosis, agitation and/or hallucinations caused by alcohol withdrawal.

By affecting neurotransmitters in the brain, Haloperidol impacts on the way patients think and behave. Haloperidol blocks dopamine receptors in the limbic system and mesocortex, for example, and, in doing so, helps to treat hallucinations and delusions. When Haloperidol impacts on the limbic system, it can also limit psychomotor agitation and has a sedative effect on patients. However, Haloperidol does act as an antagonist to dopamine receptors so may have the opposite effect in some patients and could increase restlessness and/or agitation.

Considered to be an extremely potent neuroleptic, Haloperidol affects the patient's nerve function. By depressing the nerve function, Haloperidol can relieve nervous tension and prevent patients from feeling anxious, agitated and distressed.

Furthermore Haloperidol has strong antiemetic properties due to its effect on the chemoreceptor trigger zone in the brain. Due to this, Haloperidol may be used to relieve vomiting and nausea in some patients. Particularly useful for patients who are going through chemotherapy, Haloperidol can be used to reduce the intestinal side effects associated with other treatments and medications.

Although there are a number of contra-indicators which affect the use of Haloperidol, it can be extremely effective for many patients. Individuals who have been diagnosed with schizophrenia, bipolar disorder or Tourette's syndrome, for example, can experience significant symptom reduction when treated with this medication.

Conditions Treated

Type Of Medicine

  • Antipsychotic

Side Effects

Although patients can experience side effects when taking any type of medicine, antipsychotics are known to cause adverse effects in some patients. When Haloperidol is first prescribed, the patient's physician should provide advice regarding the management of these side effects. In addition to this, additional medication may be prescribed to manage specific side effects, once the patient's response to the medication has been ascertained.

When patients first start taking Haloperidol, they may be more likely to experience side effects. Often, these will diminish as the patient gets used to the medication. Unless they are severe or troublesome, patients may not need to seek medical assistance for the following adverse effects:

  • Sour or acid stomach
  • Loss of hair
  • Belching
  • Menstrual changes
  • Blindness
  • Night blindness
  • Blurred vision or any other change in vision
  • Loss in sexual drive, ability, performance or desire
  • Decreased interest in sexual intercourse
  • Drowsiness
  • Decreased vision
  • Indigestion
  • Difficulty having a bowel movement (stool)
  • Increased watering of the mouth
  • Disturbed color perception
  • Double vision
  • Increased sensitivity of skin to sunlight
  • Feeling of constant movement of surrounding or self
  • Increased interest in sexual intercourse
  • Swelling or fullness of the breasts
  • Inability to keep or have an erection
  • Halos around lights
  • Overbright appearance of lights
  • Heartburn
  • Tenderness or pain of the breasts
  • Discoloration or redness of the skin
  • Prolonged or painful erection of the penis
  • Tunnel vision
  • Sensation of spinning
  • Difficulty sleeping
  • Severe sunburn
  • Breast soreness or swelling of the breast tissue in both males and females
  • Sleeplessness
  • Unusual secretion of milk
  • Stomach pain, upset or discomfort
  • Weight loss

There are, however, a number of other side effects which may occur when patients are taking Haloperidol. If patients experience any of the following side effects when taking this medication, they should seek medical advice:

  • Stomach or abdominal pain
  • Confusion
  • Anxiety
  • Coma
  • Tarry, black stools
  • Lumps, itching, soreness, redness or tenderness at injection site
  • Blurred vision
  • Cold sweats
  • Blistering, coldness, burning, bleeding or feeling of pressure at injection site
  • Clay-colored stools
  • Dark urine
  • Chest pain
  • Hives, discoloration of skin, infection, swelling, numbness or pain at injection site
  • Continuing nausea or vomiting
  • Chills
  • Scarring, inflammation, rash, stinging, warmth or tingling at injection site
  • Pale, cool skin
  • Convulsions
  • Hoarseness or cough
  • Decrease in frequency of urination
  • Dizziness
  • Decrease in urine volume
  • Difficulty speaking
  • Decreased urine output
  • Lightheadedness, fainting or dizziness when getting up from a lying or sitting position
  • Depression
  • Eye pain
  • Difficulty speaking
  • Fainting
  • Difficulty in passing urine (dribbling)
  • Dry mouth
  • Difficulty breathing
  • Fever
  • Drooling
  • Unusual or false sense of well-being
  • Dry, hot skin
  • Irregular, pounding or fast pulse or heartbeat
  • Headache
  • Fever
  • Flushed skin
  • Fever with or without chills
  • Inability to sit still
  • Fruit-like breath odor
  • General feeling of illness
  • Low or high blood pressure
  • General feeling of weakness or tiredness
  • Increased thirst
  • Hyperventilation
  • Lack of sweating
  • Inability to move the eyes
  • Itching
  • Increase in the frequency of seizures
  • Irritability
  • Increased spasms or blinking of the eyelid
  • Lip puckering or smacking
  • Increased hunger
  • Loss of consciousness
  • Increased sweating
  • Loss of bladder control
  • Increased thirst
  • Loss of appetite
  • Increased urination
  • Pain in side or lower back
  • Irregular heartbeat
  • Muscle weakness
  • Puffing of the cheeks
  • Muscle cramps or pain
  • Pounding in the ears
  • Muscle jerking, stiffness or trembling
  • Pale skin
  • Nausea or vomiting
  • Difficult or painful urination
  • Need to keep moving
  • Noisy breathing
  • Nervousness
  • Worm-like or rapid tongue movements
  • Nightmares
  • Slurred speech
  • Rash on the skin
  • Sore throat
  • Restlessness
  • Shuffling walk
  • Seizures
  • Chest tightness
  • Severe muscle stiffness
  • Weakness and tiredness
  • Shakiness
  • Trouble sleeping
  • Uncontrolled twisting movements of the trunk, legs, arms, neck and/or face
  • Shortness of breath
  • Unexplained weight loss
  • White spots, ulcers or sores in the mouth or on the lips
  • Sticking out of the tongue
  • Unpleasant breath odor
  • Stiffness of the limbs
  • Uncontrolled chewing movements
  • Sweating
  • Total body jerking
  • Swelling of the ankles, face or hands
  • Unusually pale skin
  • Unusual bruising or bleeding
  • Swollen glands
  • Unusual facial expressions
  • Trouble speaking
  • Vomiting
  • Trouble swallowing
  • Vomiting of blood
  • Trouble breathing
  • Yellowing of the skin or eyes
  • Troubled breathing with exertion
  • Weakness in the legs or arms
  • Unusual weakness or tiredness
  • Twisting movements of the body
  • Wheezing

In addition to this, patients should seek medical advice if they experience any other side effects which are not listed above.


When Haloperidol Decanoate is prescribed, the patient's dose will depend on their diagnosis, their current presentation, their age, weight and medical history. When adult patients with schizophrenia are treated with Haloperidol, they are usually given at least 100mg via intramuscular injection. If necessary, more than 100mg of Haloperidol can be given but should be administered via two separate injections. Following this, patients may be given Haloperidol via intramuscular injection on a monthly basis. The patient's monthly dose will normally depend on the amount of antipsychotic medication they are taking in other forms.

However, if Haloperidol Lactate is used to treat patients with schizophrenia, they will usually be given 2-5mg via intramuscular injection, every four to eight hours. Generally, the maximum daily dose of Haloperidol Lactate is 20mg, when used for this purpose.

If Haloperidol Lactate is being used to treat patients with Tourette's syndrome, the patient is normally given 2-5mg via intramuscular injection every four to eight hours. Although Haloperidol injections can be given as often as every hour, the usual maximum dose of Haloperidol for the management of Tourette's syndrome is 20mg per day.

Similarly, if patients are given Haloperidol Lactate due to psychosis or agitation, they may be given 2-5mg every four to eight hours, via intramuscular injection. Injections may be given more frequently if required but the patient's dose should not exceed 20mg per day. However, if patients are given Haloperidol Decanoate for the treatment of psychosis, they are typically given 100mg as a starting dose, followed by a monthly stabilizing dose, delivered via intramuscular injection.

As Haloperidol Lactate is typically fast-acting, it can be used to control symptoms, such as acute agitation, periods of psychosis and/or tics in patients with Tourette's syndrome. Haloperidol Decanoate is more long-lasting, however, and can be used to treat patients with long-term conditions. Once patients have begun to respond to intramuscular Haloperidol injections, they may be able to switch to taking Haloperidol in oral form.

Although pediatric patients can be prescribed Haloperidol, their dose will depend on their symptoms, age and weight. Typically, pediatric patients are treated with oral forms of Haloperidol, rather than receiving an injection. When Haloperidol is delivered via injection, the patient's dose will be calculated and measured by a healthcare professional, regardless of whether they are an adult or pediatric patient.

Potential Drug Interactions

As some drugs interact with others, it may not be appropriate for patients to be treated with Haloperidol if they are taking certain other medications. Patients will not normally be given Haloperidol if they are being treated with any of the following medicines, for example:

  • Amifampridine
  • Ziprasidone
  • Bepridil
  • Thioridazine
  • Bromopride
  • Posaconazole
  • Cisapride
  • Saquinavir
  • Dronedarone
  • Sparfloxacin
  • Fluconazole
  • Nelfinavir
  • Terfenadine
  • Levomethadyl
  • Pimozide
  • Mesoridazine
  • Piperaquine
  • Metoclopramide

Although Haloperidol is not usually prescribed in conjunction with the following medications, doctors may deem it appropriate in some cases:

  • Acecainide
  • Clarithromycin
  • Ajmaline
  • Citalopram
  • Alfentanil
  • Ciprofloxacin
  • Alfuzosin
  • Chlorpromazine
  • Amiodarone
  • Chloroquine
  • Amisulpride
  • Chloral Hydrate
  • Amitriptyline
  • Ceritinib
  • Anagrelide
  • Desipramine
  • Apomorphine
  • Delamanid
  • Aprindine
  • Degarelix
  • Aripiprazole
  • Clomipramine
  • Arsenic Trioxide
  • Codeine
  • Artemether
  • Conivaptan
  • Asenapine
  • Crizotinib
  • Astemizole
  • Cobicistat
  • Azimilide
  • Dalfopristin
  • Azithromycin
  • Dasatinib
  • Bedaquiline
  • Darunavir
  • Bretylium
  • Dabrafenib
  • Bromazepam
  • Doxylamine
  • Buprenorphine
  • Disopyramide
  • Bupropion
  • Dihydrocodeine
  • Buserelin
  • Doxepin
  • Butorphanol
  • Efavirenz
  • Deslorelin
  • Hydroquinidine
  • Dibenzepin
  • Flibanserin
  • Dofetilide
  • Hydroxychloroquine
  • Dolasetron
  • Fluoxetine
  • Domperidone
  • Fentanyl
  • Donepezil
  • Fingolimod
  • Droperidol
  • Gatifloxacin
  • Encainide
  • Goserelin
  • Enflurane
  • Gemifloxacin
  • Erythromycin
  • Gonadorelin
  • Escitalopram
  • Granisetron
  • Flecainide
  • Morphine Sulfate Liposome
  • Foscarnet
  • Lopinavir
  • Halofantrine
  • Lithium
  • Histrelin
  • Lorcainide
  • Hydrocodone
  • Leuprolide
  • Hydromorphone
  • Mifepristone
  • Levofloxacin
  • Hydroxyzine
  • Metronidazole
  • Ibutilide
  • Milnacipran
  • Idelalisib
  • Morphine
  • Imipramine
  • Methadone
  • Itraconazole
  • Mefloquine
  • Ivabradine
  • Ketoconazole
  • Meperidine
  • Lapatinib
  • Pazopanib
  • Lumefantrine
  • Pentamidine
  • Moxifloxacin
  • Paroxetine
  • Nafarelin
  • Paliperidone
  • Nilotinib
  • Panobinostat
  • Norfloxacin
  • Pasireotide
  • Triptorelin
  • Nortriptyline
  • Ranolazine
  • Octreotide
  • Sertraline
  • Ofloxacin
  • Sertindole
  • Ondansetron
  • Sematilide
  • Oxycodone
  • Selegiline
  • Oxymorphone
  • Salmeterol
  • Pentazocine
  • Sulfamethoxazole
  • Perflutren Lipid Microsphere
  • Solifenacin
  • Periciazine
  • Sorafenib
  • Pimavanserin
  • Sotalol
  • Pitolisant
  • Spiramycin
  • Pixantrone
  • Sufentanil
  • Probucol
  • Sodium Phosphate, Monobasic
  • Procainamide
  • Sodium Phosphate, Dibasic
  • Prochlorperazine
  • Sodium Phosphate
  • Promethazine
  • Sevoflurane
  • Tetrabenazine
  • Propafenone
  • Tacrolimus
  • Propranolol
  • Sultopride
  • Protriptyline
  • Telavancin
  • Quetiapine
  • Telithromycin
  • Quinidine
  • Tapentadol
  • Quinine
  • Tedisamil
  • Quinupristin
  • Tramadol
  • Remifentanil
  • Vandetanib
  • Trazodone
  • Risperidone
  • Venlafaxine
  • Sulpiride
  • Vardenafil
  • Sunitinib
  • Vemurafenib
  • Tizanidine
  • Vinflunine
  • Toremifene
  • Voriconazole
  • Trifluoperazine
  • Zotepine
  • Trimethoprim
  • Zuclopenthixol
  • Trimipramine

If patients are treated with Haloperidol in conjunction with the following medicines, it may increase the risk of side effects occurring:

  • Benztropine
  • Trihexyphenidyl
  • Betel Nut
  • Rifapentine
  • Procyclidine
  • Buspirone
  • Nefazodone
  • Carbamazepine
  • Methyldopa
  • Dextromethorphan
  • Tacrine
  • Fluvoxamine
  • Rifampin
  • Olanzapine

As prescription medications can also interact with over-the-counter medicines, vitamins, supplements, foods, alcohol, recreational drugs and cigarettes, patients should inform their doctor if they are using any of these substances before they are treated with Haloperidol. Patients should be particularly aware that Haloperidol can interact with the following substance:

  • Tobacco

Patients should also obtain medical advice before using any new over-the-counter medicines, supplements or vitamins once they are being treated with Haloperidol.


The presence of any of these medical conditions may affect the use of Haloperidol. Due to this, patients will need to disclose their medical history to their physician before they are given Haloperidol. The following conditions, in particular, can affect the suitability of Haloperidol as a treatment:

  • Thyrotoxicosis
  • Prolactin-dependent breast cancer
  • Lung disease
  • Underactive thyroid (Hypothyroidism)
  • Chest pain
  • Low levels of magnesium in the blood (Hypomagnesemia)
  • Low levels of potassium in the blood (Hypokalemia)
  • Blood vessel or heart disease
  • Heart rhythm problems
  • Parkinson's disease
  • High levels of prolactin in the blood (Hyperprolactinemia)
  • Low blood pressure (Hypotension)
  • Dementia
  • Central nervous system depression
  • Epilepsy and/or seizures
  • Coma
  • Neuroleptic malignant syndrome
  • Mania

Although Haloperidol injections may be prescribed to geriatric patients, they should not be used to treat dementia in elderly patients. Furthermore, geriatric patients may have age-related health conditions which mean that their dose of Haloperidol should be reduced. In addition to this, geriatric patients may be more at risk of experiencing tardive dyskinesia as a side effect of Haloperidol.

Tardive dyskinesia is a movement disorder and patients should seek immediate medical help if they display the following symptoms:

  • Puffing of the cheeks
  • Lip puckering or smacking
  • Worm-like or rapid movements of the tongue
  • Uncontrolled movement of the arms or legs
  • Uncontrolled chewing movements

If patients experience any of the following symptoms after receiving treatment with Haloperidol, it may indicate they are experiencing a problem with their heart and emergency treatment is required:

  • Trouble breathing
  • Fast heartbeat
  • Chest discomfort or pain
  • Fever
  • Chills

When receiving treatment with Haloperidol, patients may be at risk of developing neuroleptic malignant syndrome (NMS). If so, the patient will require urgent medical treatment. NMS may be characterized by the following symptoms:

  • Fast heartrate
  • Seizures (convulsions)
  • Trouble breathing
  • Loss of bladder control
  • High fever
  • Tiredness
  • Increased sweating
  • Low or high blood pressure
  • Unusually pale skin
  • Severe muscle stiffness

Haloperidol can cause patients to sweat less than usual and this can result in their body temperature increasing. Patients are, therefore, more likely to suffer from heatstroke and should be careful not to overheat when exercising or when in hot temperatures.

Haloperidol can cause patients to feel dizzy, drowsy, faint, lightheaded and less alert than usual. These side effects can be more pronounced when patients get up from sitting or lying down. When getting up, patients should move slowly in order to minimize these side effects. In addition to this, patients should not drive, operate machinery or carry out tasks which require their full attention while they are experiencing these side effects.

This medicine will increase the effects of other central nervous system depressants, such as alcohol, sedatives, tranquilizers, antihistamines, allergy medicines, pain medications, narcotics, sleeping medications, seizure medications or barbiturates, anesthetics and/or muscle relaxants.

As Haloperidol can affect the way anesthetics work, patients should inform their doctor and/or dentist that they are using this medication before undergoing any procedures or dental work.

As a Haloperidol injection can temporarily reduce the patient's number of white blood cells, they may have an increased chance of contracting an infection. Patients should, therefore, avoid being exposed to people who have an existing infection. If patients exhibit any signs of becoming unwell, such as chills, fever, cough, hoarseness, painful and difficult urination or pain in the lower back or side, they should seek medical assistance.

Generally, patients are not treated with Haloperidol if they are pregnant as it may pose a risk to the unborn fetus. If patients are given Haloperidol during their third trimester, for example, the baby may experience withdrawal symptoms following birth. This may require neonatal intensive care treatment. However, if no suitable alternative is available and doctors believe treatment with Haloperidol is necessary, they may prescribe the medication to patients who are pregnant.

If patients become pregnant when they are being treated with Haloperidol, they should inform their doctor immediately. Similarly, if patients plan to become pregnant and are being treated with Haloperidol, they should discuss this with their physician before attempting to conceive.

As Haloperidol can be passed from the patient to an infant via breastfeeding, patients are usually advised not to breastfeed when they are being treated with this medicine. Patients should obtain medical advice before nursing a child whilst they are being treated with Haloperidol.

Before beginning treatment, patients should inform their physician if they have any known allergies. If patients exhibit any of the following symptoms, an allergic reaction may be occurring and emergency medical help should be obtained:

  • Wheezing
  • Itching
  • Rash on the skin
  • Hives
  • Hoarseness
  • Difficulty swallowing
  • Difficulty breathing
  • Swelling of the hands, face, lips, throat, tongue and/or mouth


Normally, Haloperidol is stored in ampoules and should be kept at a controlled room temperature of 15°-30°C (59°-86°F).

Generally, Haloperidol should not be refrigerated or frozen but should be protected from the light.

As Haloperidol injections are administered in a clinical setting, patients should not be required to store this form of Haloperidol at home.


Although Haloperidol and other antipsychotic medications are associated with a number of side effects, and these will not necessary reduce the effectiveness of treatment. In many cases, side effects diminish over time and, if required, additional treatment can be given to relieve these adverse effects.

As Haloperidol can be administered in a number of forms, it is suitable for treating patients who have differing clinical presentations. If hallucinations or agitation is making the patient resistant to taking oral medication, for example, Haloperidol can be administered via intramuscular injection. With long-term treatment delivered via a monthly injection, this is a fairly unobtrusive form of treatment.

When used successfully, Haloperidol can offer significant relief from the symptoms of schizophrenia, psychosis, bipolar disorder, alcohol withdrawal and Tourette's syndrome. By reducing the delusions, hallucinations, agitation, anxiety and tics associated with these conditions, the patient's distress and discomfort can be reduced and their quality of life can be greatly improved.