BMA Concise Guide to Medicine & Drugs

Haloperidol

Brand names Dozic, Haldol, Serenace

Used in the following combined preparations None

QUICK REFERENCE

Drug group Butyrophenone antipsychotic drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Introduced in the 1960s, haloperidol is an antipsychotic drug used to treat schizophrenia and other psychoses, mania, and to reduce agitation and violent behaviour. Haloperidol is also used in the short term to treat severe anxiety. It does not cure the underlying disorder but relieves the distressing symptoms. The drug is also used in the control of Tourette’s syndrome and to treat intractable hiccups.

The main drawback of haloperidol is that it can produce the side effect of abnormal, involuntary movements of the face and stiffness of the limbs. As a result, it is no longer recommended for first-line treatment of schizophrenia.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, capsules, liquid, injection, depot injection.

Frequency and timing of doses 2–4 x daily.

Adult dosage range Mental illness 3–10mg daily initially, up to a maximum of 30mg daily. Severe anxiety 1mg daily.

Onset of effect 2–3 hours (by mouth); 20–30 minutes (by injection).

Duration of action 6–24 hours (by mouth); 2–4 hours (injection); up to 4 weeks (depot injection).

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 3 hours, take a single dose now and skip the next.

Stopping the drug Do not stop the drug without consulting your doctor; symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Larger overdoses may cause unusual drowsiness, muscle weakness or rigidity, and/or faintness. Notify your doctor.

POSSIBLE ADVERSE EFFECTS

Various minor anticholinergic symptoms, such as dry mouth and blurred vision, can occur but often diminish with time. Drowsiness, lethargy, sexual dysfunction, and breathlessness may also occur. The most significant adverse effects of haloperidol are abnormal movements of the face and limb stiffness (parkinsonism), which may be controlled by adjusting the dosage. Rarely, the drug causes a high fever or confusion; if so, you should stop taking it and consult your doctor immediately.

INTERACTIONS

Sedatives Sedatives are likely to increase the sedative properties of haloperidol.

Rifampicin and anticonvulsants These drugs may reduce the effects of haloperidol, the dosage of which may need to be increased.

Lithium This drug may increase the risk of parkinsonism and effects on the nerves.

Methyldopa This drug may increase the risk of parkinsonism and low blood pressure.

Anticholinergic drugs Haloperidol may increase the side effects of these drugs.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have heart or circulation problems.

· You have had epileptic seizures.

· You have Parkinson’s disease or other movement disorders.

· You are taking other medicines.

Pregnancy Short-term nervous system problems may occur in babies when haloperidol is taken during the third trimester. The drug is occasionally used under psychiatric supervision. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk and may affect the baby. Discuss with your doctor.

Infants and children Rarely required. Reduced dose necessary.

Over 60 Reduced dose may be necessary.

Driving and hazardous work Avoid such activities until you have learned how haloperidol affects you because the drug may cause drowsiness and slowed reactions.

Alcohol Avoid. Alcohol may increase the sedative effect of this drug.

PROLONGED USE

Use of this drug for more than a few months may lead to tardive dyskinesia (abnormal, involuntary movements of the eyes, face, and tongue). Occasionally, jaundice may occur.