Drugs used in Psychosis and related disorders

When prescribing an antipsychotic for administration on an emergency basis, the intramuscular dose should be lower than the corresponding oral dose (owing to absence of first-pass effect), particularly if the patient is very active (increased blood flow to muscle considerably increases the rate of absorption). The prescription should specify the dose for each route and should not imply that the same dose can be given by mouth or by intramuscular injection. The dose of antipsychotic for emergency use should be reviewed at least daily.

Antipsychotic drugs

Antipsychotic drugs generally tranquillise without impairing consciousness and without causing paradoxical excitement but they should not be regarded merely as tranquillisers. For conditions such as schizophrenia the tranquillising effect is of secondary importance. In the short term they are used to quieten disturbed patients whatever the underlying psychopathology, which may be schizophrenia, brain damage, mania, toxic delirium, or agitated depression. Antipsychotic drugs are used to alleviate severe anxiety but this too should be a short-term measure. Selection is influenced by the degree of sedation required and the patient’s susceptibility to extrapyramidal side-effects. However, the differences between antipsychotic drugs are less important than the great variability in patient response; moreover, tolerance to secondary effects such as sedation usually develops. The atypical antipsychotics may be appropriate if extrapyramidal side-effects are a particular concern. Prescribing of more than one antipsychotic at the same time is not recommended; it may constitute a hazard and there is no significant evidence that side-effects are minimised.

CHLORPROMAZINE HYDROCHLORIDE:

Indications: Acute Intermittent Porphyria, Intractable Hiccups, Manic Bipolar Disorder, Nausea and Vomiting, Pre-Op Apprehension, Schizophrenia.

Contraindications: Coma, Lactating Mother, Neuroleptic Malignant Syndrome, Severe Cardiovascular Disease, Stupor, Breast Carcinoma, Conduction Disorder of the Heart, Congenital Long QT Syndrome, Disease of Liver, Extrapyramidal Disease, Glaucoma, Metabolic Syndrome X, Myocardial Infarction, Myocardial Ischemia, Obesity, Organophosphate Insecticide Poisoning, Prolonged QT Interval, Senile Dementia, Symptomatic Prostatic Hypertrophy, Tardive Dyskinesia, Torsades de Pointes, Urinary Retention

Dose and Administration: By mouth, schizophrenia and other psychoses, mania, short-term adjunctive management of severe anxiety, psychomotor agitation, excitement, and violent or dangerously  impulsive behaviour initially 25 mg 3 times daily (or 75 mg at night), adjusted according to response, to usual maintenance dose of 75–300 mg daily (but up to 1 g daily may be required in psychoses); elderly (or debilitated) third to half adult dose; child (childhood schizophrenia and autism) 1–5 years 500 micrograms/kg every 4–6 hours (max. 40 mg daily); 6–12 years 10 mg 3 times daily (max. 75 mg daily). By deep intramuscular injection, (for relief of acute symptoms but see also Cautions and Side-effects), 25–50 mg every 6–8 hours; child, 1–5 years 500 micrograms/kg every 6–8 hours (max. 40 mg daily); 6–12 years 500 micrograms/kg every 6–8 hours (max. 75 mg daily). Induction of hypothermia (to prevent shivering), 25– 50 mg every 6–8 hours; child 1–12 years, initially 0.5–1 mg/kg, followed by maintenance 500 micrograms/kg every 4–6 hours.

FLUPENTHIXOL:

Indications: schizophrenia and other psychoses, particularly with apathy and withdrawal but not mania or psychomotor hyperactivity; depression.

Contraindications: hepatic impairment; renal impairment; pregnancy; breast-feeding.

Dose and Administration: Psychosis, initially 3–9 mg twice daily adjusted according to the response; max. 18 mg daily; elderly (or debilitated) initially quarter to half adult dose; child not recommended.

HALOPERIDOL:

Indications: Acute Schizophrenia, Aggressive Behavior, Chronic Schizophrenia, Drug-Induced Psychosis, Gilles De La Tourette Syndrome, Manic Disorder, Organic Psychotic Condition, Psychotic Disorder, Schizophrenia

Contraindications: CNS Depression, Coma, Drug Induced CNS Depression, Lactating Mother, Parkinsonism, Torsades de Pointes, Agranulocytosis, Angina, Congenital Long QT Syndrome, Hypokalemia, Hypomagnesemia, Neuroleptic Malignant Syndrome.

Dose and Administration: schizophrenia and other psychoses, mania, short-term adjunctive management of psychomotor agitation, excitement, and violent or dangerously impulsive behaviour, by mouth, initially 1.5–3 mg 2–3 times daily or 3–5 mg 2–3 times daily in severely affected or resistant patients; in resistant schizophrenia up to 30 mg daily may be needed; adjusted according to response to lowest effective maintenance dose (as low as 5–10 mg daily); elderly (or debilitated) initially half adult dose; child initially 25–50 micrograms/kg daily (in 2 divided doses) to max. 10 mg. By intramuscular or by intravenous injection, initially 2–10 mg, then every 4–8 hours according to response to total max. 18 mg daily; severely disturbed patients may require initial dose of up to 18 mg; elderly (or debilitated) initially half adult dose; child not recommended. Agitation and restlessness in the elderly, by mouth, initially 0.5–1.5 mg once or twice daily.

SULPIRIDE:

Indications: schizophrenia and other psychoses.

Contraindications: hepatic impairment, renal impairment, cardiovascular disease, Parkinson’s disease (may be exacerbated by antipsychotics), epilepsy (and conditions predisposing to epilepsy), depression, myasthenia gravis, prostatic hypertrophy, or a susceptibility to angle-closure glaucoma

Dose and Administration: 200–400 mg twice daily; max. 800 mg daily in predominantly negative symptoms, and 2.4 g daily in mainly positive symptoms; elderly, lower initial dose, increased gradually according to response; child under 14 years not recommended.

TIAPRIDE:

Indications: Treatment of certain beha-vioural disorders and for the treatment of certain types of intense and referactory pains.

Contraindications: prolactin dependent tumor, pheochromocytoma.

Dose and Administration: dosage is variable and has to be adjusted to each individual case. For use in adults and children over the age of 6 years only.

ZUCLOPENTHIXOL ACETATE:

Indications: short-term management of acute psychosis, mania, or exacerbations of chronic psychosis

Contraindications: hepatic impairment; renal impairment; pregnancy; breast-feeding.

Dose and Administration: By deep intramuscular injection into the gluteal muscle or lateral thigh, 50–150 mg (elderly 50–100 mg), if necessary repeated after 2–3 days (1 additional dose may be needed 1–2 days after the first injection); max. cumulative dose 400 mg per course and max. 4 injections; max. duration of treatment 2 weeks—if maintenance treatment necessary change to an oral antipsychotic 2–3 days after last injection, or to a longer acting antipsychotic depot injection given concomitantly with last injection of zuclopenthixol acetate; child not recommended

ZUCLOPENTHIXOL:

Indications: schizophrenia and other psychoses, particularly when associated with agitated, aggressive, or hostile behaviour

Contraindications: hepatic impairment; renal impairment; pregnancy; breast-feeding and apathetic or withdrawn states.

Dose and Administration: By mouth, initially 20–30 mg daily in divided doses, increasing to a max. of 150 mg daily if necessary; usual maintenance dose 20– 50 mg daily; elderly (or debilitated) initially quarter to half adult dose; child not recommended​