NZ Formulary

Haloperidol (injection)

hal-oh-peer-ih-dol

What does it do?

Haloperidol is used to treat some mental health problems such as schizophrenia. It is also sometimes used for other conditions such as nausea and vomiting.

How is it given?

Haloperidol is given as an injection into a vein, muscle or under the skin.

What if you forget a dose?

If you miss an appointment for your injection, contact your health professional as soon as possible.

Can you take other medicines?

Some medicines available without a prescription may react with haloperidol including:

  • some antihistamines (may be in anti-allergy, anti-nausea and cough/cold medicines)
  • anti-nausea medicines (e.g. prochlorperazine, hyoscine (e.g. Scopoderm TTS®), meclozine (e.g. Sea-legs®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort, valerian) or recreational drugs (e.g. cannabis).

Important information continues on next page.

What side effects might you notice?

Side EffectsRecommended action

Fever, stiffness, sweating, confusion

Feeling restless, strange or uncontrolled movements, tremor

Fast or irregular heartbeat, fainting

Symptoms of a blood clot including: sudden shortness of breath, swelling or pain in one leg

Seizures

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Prolonged erection (longer than four hours)

Tell your doctor immediately

Drowsiness, dizziness

Weight gain

Dry mouth, blurred vision, constipation, trouble peeing

Stomach upset

Changes in periods

Sore or enlarged breasts, breastmilk production

Less interest in sex, impotence

Pain, tenderness or redness at injection site

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have heart, liver, bowel, bladder, prostate or eye (e.g. glaucoma) problems.
  • Tell your doctor if you have diabetes, Parkinson’s disease, have ever had a seizure, blood clot, stroke or ‘mini-stroke’, or if you have experienced strange body movements with another medicine.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Your doctor may do a heart test (ECG) before you start and while you are taking haloperidol.
  • Haloperidol can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • Smoking can change the effect of haloperidol. Tell your doctor if you give up, cut down or start smoking.
  • Haloperidol reduces your body’s ability to maintain a normal temperature. Be careful of becoming too cold or too hot. When exercising, drink plenty of water.
  • You have an increased risk of getting diabetes while taking haloperidol. Discuss with your doctor.
  • If you are taking haloperidol regularly, do not stop taking it without talking to your doctor.