Haloperidol



A) Haloperidol is classified as a typical antipsychotic.  It is neither an SSRI or SNRI antidepressant.

Haloperidol is a psychotropic drug of the butyrophenon series and is not related chemically to phenothiazine's. (although has pharmacological effects similar to the phenothiazine's).  Although the mechanism of the therapeutic effect of Haloperidol is not clearly established, it is known that it produces a selective effect on the central nervous system by competitive blockade of postsynaptic dopamine (D2) receptors in the mesolimbic dopaminergic system, and an increased turnover of the brain dopamine to produce its tranquillising effects. 

B) Common brand names are : Serenace, Aloperidin, Haldol (common trade name in the US and UK) and Sigaperidol.

For the sake of Mental Health usage, there is a fast acting and long acting form of Haloperidol. 

Haloperidol Decanoate is a long-acting form of haloperidol.  The basic effects of haloperidol decanoate are the same as Haloperidol with the exception of the duration of action.  When it is administered as an intramuscular Depot injection it provides a slow release of the active neuroleptic Haloperidol from the depot into the systemic circulation.  Haloperidol blocks the effects of dopamine and increases its turnover rate, however the precise mechanism of action is unknown.

Serenace (Haloperidol) is used in the control of the symptoms of e.g.

- Schizophrenia

- Acute psychosis, such as drug induced psychosis caused by LSD, amphetamines, ketamine and psychosis associated with high fever or metabolic disease.

- Hyperactivity, aggression

- Hyperactive delirium (to control the agitation component of delirium)

- Adjunctive treatment of alcohol and opioid withdrawal

- Treatment of severe nausea

- Treatment of neurological disorders such as tic disorders, Tourette syndrome, and chorea

- Therapeutic trial in personality disorders, such as borderline personality disorders

- Treatment of intractable hiccups

- Alcohol-induced psychosis. 

C)  Normal dose ranges:  For agitation and aggressiveness associated with acute psychosis (e.g.. Mania, acute schizophrenia, toxic confusional states), Parenteral:  2-10mg IM or IV initially.  The amount will depend on the patient's age, physical status and severity of symptoms.  Depending on the response of the patient, subsequent doses may be given as often as half hourly for IV injection or hourly for IM injections.  The total daily dose administered should not exceed 100mg.

Oral: Moderate Symptomatology : 1-5mg per day

Severe Symptomatology:  5-15mg per day.  Daily oral doses should be titrated against patient response and my be increase up to 100mg.  Once a satisfactory clinical response has been achieved, the daily dose should be reduced to the lowest effective level.

Geriatric or Debilitated Patients: 1-3mg per day is usually sufficient.

Children:  For severely aggressive or hostile children or for the rare case Gilles de la Tourette Syndrome, the initial dose should be 1-3mg per day and Serenace liquid is recommended (10-30 drops).  Maintenance dose is usually 0.05 mg/kg body weight per day.

D)  Common Side Effects:  Akatheisa: may be appear within the first 6 hours after dose.

Dystonia's: Can produce laryngeal spasm or bronchospasm may be controlled by IV or IM administration of benztropine mesylate or IV diazepam.

Parkinsonian effects: are characterised by difficulty in speaking and swallowing, loss of balance control, mask-like face, shuffling gait, stiffness in arms or legs, trembling and shaking in hands and fingers.

Tardive dyskinesia: Lip smacking or puckering, puffing of cheeks, rapid or abnormal movements of the tongue, uncontrolled chewing movements and uncontrolled movements of the arms and legs.

Neuroleptic Malignant Syndrome (NMS):  Characterised by difficult or unusually fast breathing, fast heartbeat or irregular pulse, high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, seizures, unusual tiredness or weakness, unusually pale skin, rhabdomyolyis and acute renal failure.

Tardive Dystonia:  Increase blinking or spasm of eyelid, unusual facial expressions or body positions, uncontrolled twisting movement's of neck, trunk, arms and legs.

Other side effects are Drowsiness, depression, anxiety, euphoria, lethargy, agitation, insomnia, headache, confusion, sedation, anorexia, vertigo, restlessness, apprehension, seizures and toxic psychosis may occur with overdose.

There can be also Cardiovascular side effects e.g. Orthostatic hypotension, Tachycardia and increased respiratory rate, QT prolongation, Ventricular arrhythmias and Polymorphous configuration of torsade de pointes.

Haematological Side effects: e.g. Anaemia, Agranulocytosis (Sore throat and fever, unusual bleeding or bruising), Leukopenia and leucocytosis.

Hepatobiliary Side effects:  Impaired liver function and/or Jaundice.

Respiratory side effects:  Laryngospasm, Bronchospasm, increased depth of respiration, Bronchopneumonia.

Dermatological:  Hypersensitivity, Local reactions as erythema, swelling or tender lumps, urticarial, dermatitis.

Endocrine Side effects: Hyperprolactinaemia, Impotence or increase libido, Lactation, Hyperglycaemia, Hypoglycaemia, Hyponatraemia.

Gastrointestinal Side Effects:  Constipation, Anorexia, Nausea, Vomiting, Diarrhoea, Dyspepsia, Hyper salivation.

Autonomic side effects:  Blurred Vision, Dryness of mouth, Urinary retention, excessive perspiration or salivation.

Ocular Side effects: Cataract, Retinopathy, Visual disturbances

Others: Heat Stroke, increased sensitivity of skin to sun, weight gain and Peripheral oedema.

Contraindications:

Comatose states, in the presence of central nervous system depression due to alcohol and other depressant drugs, severe depressive states, previous spastic diseases, Mental Health patients with pre-existing parkinsonian symptoms; Parkinson's disease, known hypersensitivity to haloperidol; in patients with manifest occult lesions of the basal ganglia; and in patients with prolactin dependent tumours.  Seranace is also contraindicated in patients who are sensitive to haloperidol or other ingredients in the dosage form.

F)  Special monitoring/Nursing care requirements. 

Observe for Neuroleptic Malignant Syndrome (NMS), Tardive Dyskinesia, QT Prolongation and Torsades de Pointes, (Because of risk of Torsades de Pointes and QT prolongation, ECG monitoring is recommended),  Alcoholism - CNS depression may be potentiated and risk of stroke may be increased.  Increased hypotensive effects and the potential for alcohol intoxication may also occur.

Severe Cardiovascular disease, Anginal pain may be provoked in patients with ischaemic heart disease, Epilepsy - Haloperidol maybe administered to epileptics but adequate anticonvulsant therapy should be maintained as haloperidol may decrease the seizure threshold.  Observe for history of epilepsy, Glaucoma - or a predisposition to glaucoma may be triggered because of the secondary anticholinergic effects of haloperidol.  Hepatic Function, hyperthyroidism thyrotoxicosis e.g. severe neurotoxicity such as rigidity and inability to walk or talk may result.  These patients should always be accompanied and appropriate monitoring and therapy.

Pulmonary Insufficiency:  Haloperidol should be used with caution in patients with pulmonary insufficiency such as asthma, emphysema or acute pulmonary infections.  Haloperidol may cause potentiation of breathing impairment and my lead to a pneumonia.  Renal function impairment, Urinary retention, elderly and debilitated patients, Bipolar Mood Disorder ( can cause a rapid mood swing in cyclic disorders to depression).  As with all antipsychotic agents, Haloperidol should not be used alone where depression in predominant ( can be combined with antidepressants where depression and psychosis coexist).  Haloperidol may impair the metabolism of tricyclic antidepressants.

Dental:  Patients should be instructed in proper oral hygiene as the leukopenic and thrombocytopenic effects of haloperidol may result in an increase incidence of microbial infection, delaying healing and gingival bleeding. (caution in the use of regular toothbrushes, dental floss and toothpicks).

Antiemetic action of haloperidol may relieve nausea and vomiting, and so obscure the diagnosis of an underlying organic disorder which was causing these symptoms.

G) Education requirements for patients/families and carers:

Watch for adverse effects noted above and contraindications noted also.  Tell Medical/Nursing staff if any past history of acute stroke, severe intoxication with alcohol or other CNS depressant drugs.  Known allergy against Haloperidol or other butyrophenones or other drug ingredients.  Known heart disease (when combined can even cause cardiac arrest).  Pre-existing Parkinson's disease or dementia.  Patients at special risk for the development of QT prolongation, Hypokalaemia or other drugs causing QT prolongation. 

Compromised liver function, as haloperidol is metabolised and eliminated by mainly by the liver.  IV injections: risk of hypotension or orthostatic collapse.

Patients with a history of leukopenia: a complete blood count should be monitored frequently during the first few months of treatment.

Report if any headaches, Jaundice, Hyper/hypo-glycaemia, Seizure, any respiratory problems, psychotic disorder, vomiting, oedema, hyper/hypo-thermia, Tardive dyskinesia, NMS, Chest pain or cardiac problems.  Tell staff if on antiparkinson's meds, Tricyclic antidepressants or lithium (can cause encephalopathy and early and late extrapyramidal side effects).

Paul Barras