Dosage/Direction for Use
Oral Intractable hiccup Adult: Initially, 25-50 mg 3-4 times daily for 2-3 days; if unresponsive, may admin 25-50 mg via IM inj. If still necessary, 25-50 mg in 500-1000 ml of normal saline may be given via slow IV infusion. Child: 1-12 yr: 500 mcg/kg every 4-6 hr. Max: >5 yr: 75 mg daily; 1-5 yr: 40 mg daily. Elderly: Initially, 1/3-½ the normal adult dose. Oral Psychoses Adult: 25 mg tid; may be given as a single 75 mg dose at night. Maintenance: 25-100 mg tid increased to ≥1 g daily as required in psychotic patients. Child: 1-12 yr: 500 mcg/kg every 4-6 hr. Max: >5 yr: 75 mg daily; 1-5 yr: 40 mg daily. Elderly: Initially, 1/3-½ the normal adult dose. Intramuscular Psychoses Adult: 25-50 mg repeated every 6-8 hr. Substitute with oral therapy as soon as possible. Child: 1-12 yr: 500 mcg/kg every 4-6 hr. Max: >5 yr: 75 mg daily; 1-5 yr: 40 mg daily. Elderly: Initially, 1/3-½ the normal adult dose. Intramuscular Nausea and vomiting Adult: Initially, 25 mg via IM inj, followed by 25-50 mg every 3-4 hr until vomiting stops. Child: 1-12 yr: 500 mcg/kg every 4-6 hr. Max: >5 yr: 75 mg daily; 1-5 yr: 40 mg daily. Elderly: Initially, 1/3-½ the normal adult dose. |
Administration
May be taken with or without food. May be taken w/ meals to reduce GI discomfort.
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Contraindications
Hypersensitivity; preexisting CNS depression, coma, bone-marrow supression; phaeochromocytoma; lactation.
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Special Precautions
Parkinson's disease; CV disease; renal or hepatic impairment; cerebrovascular and respiratoty disease; jaundice; DM; hypothyroidism; paralytic ileus; prostatic hyperplasia or urinary retention; epilepsy or history of seizures; myasthenia gravis; pregnancy; elderly (especially with dementia), and debilitated patients. Avoid direct sunlight.
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Adverse Reactions
Tardive dyskinesia (on long-term therapy). Involuntary movements of extremities may also occur. Dry mouth, constipation, urinary retention, mydriasis, agitation, insomnia, depression and convulsions; postural hypotension, ECG changes. Allergic skin reaction, amenorrhoea, gynaecomastia, weight gain. Hyperglycaemia and raised serum cholesterol.
Potentially Fatal: Agranulocytosis. Instantaneous deaths associated with ventricular tachyarrhythmias. Marked elevation of body temperature with heat stroke. Neuroleptic malignant syndrome, extrapyramidal dysfunction. |
Overdosage
Symptoms include somnolence, coma, hypotension and extrapyramidal symptoms. Other possible manifestations include agitation and restlessness, convulsions, fever, autonomic reactions such as dry mouth and ileus, EKG changes and cardiac arrhythmias.
Treatment is symptomatic and supportive. Early gastric lavage may be helpful. Observe patient and maintain an open airway.
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Drug Interactions
Potentiation of anticholinergic effects of antiparkinson agents and TCAs may lead to an anticholinergic crisis. Additive orthostatic hypotensive effect in combination with MAOIs. Reverses antihypertensive effect of guanethidine, methyldopa and clonidine.
Potentially Fatal: Additive depressant effect with sedatives, hypnotics, antihistamines, general anaesthetics, opiates and alcohol. |
Action
Chlorpromazine is a neuroleptic that acts by blocking the postsynaptic dopamine receptor in the mesolimbic dopaminergic system and inhibits the release of hypothalamic and hypophyseal hormones. It has antiemetic, serotonin-blocking, and weak antihistaminic properties and slight ganglion-blocking activity.
Onset: 15 min (IM); 30-60 min (oral). Absorption: Readily but sometimes erratically absorbed from the GI tract (oral); peak plasma concentrations after 2-4 hr. Distribution: Widely distributed; crosses the blood-brain barrier and placenta; enters breast milk. Metabolism: Extensively hepatic by hydroxylation and conjugation with glucuronic acid, N-oxidation, oxidation of a sulfur atom and dealkylation. Excretion: Urine and faeces (as active and inactive metabolites); 30 hr (elimination half-life). |
Storage
Intramuscular: Store at 15-30°C. Oral: Store at 15-30°C.
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CIMS Class
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ATC Classification
N05AA01 - chlorpromazine ; Belongs to the class of phenothiazine antipsychotics with aliphatic side-chain.
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