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Therapeutic action
- Sedative antipsychotic
Indications
- Acute or chronic psychosis, in the event of intolerance or treatment failure with other antipsychotics (preferably use haloperidol for this indication)
Forms and strengths
- 25 mg and 100 mg tablets
Dosage
- Adult: 25 to 50 mg once daily in the evening for one week. Increase gradually to 50 mg in the morning and 100 mg in the evening; if insufficient, administer 100 mg 3 times daily.
- Reduce the dose by half in older patients.
- Use the lowest effective dose, especially in the event of prolonged treatment.
Duration
- Acute psychosis: at least 3 months
- Chronic psychosis: at least one year
Discontinue treatment gradually (over 4 weeks). If signs of relapse occur, increase the dose then decrease it more gradually.
Contra-indications, adverse effects, precautions
- Do not administer to patients with cardiac disorders (heart failure, recent myocardial infarction, conduction disorders, bradycardia, etc.), dementia (e.g. Alzheimer's disease), closed-angle glaucoma, prostate disorders, Parkinson's disease and history of neuroleptic malignant syndrome.
- Administer with caution and carefully monitor use in older patients and patients with hypokalaemia, hypotension, renal or hepatic impairment, history of seizures.
- May cause:
- drowsiness (caution when driving/operating machinery), dyskinesia, extrapyramidal symptoms, weight gain, orthostatic hypotension, hyperprolactinaemia, anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, tachycardia);
- hyperglycaemia, photosensitivity, impaired thermoregulation; agranulocytosis, neuroleptic malignant syndrome (unexplained hyperthermia with neuromuscular disorders), rare but requiring immediate treatment discontinuation.
- In case of extrapyramidal symptoms, try reducing the dose of chlorpromazine or, if the extrapyramidal symptoms are severe, add biperiden or trihexyphenidyl.
- Avoid or monitor combination with:
- central nervous system depressants (opioid analgesics, sedatives, H1 antihistamines, etc.); drugs with anticholinergic effects (amitriptyline, atropine, promethazine, etc.), antidiabetics, lithium;
- antihypertensive drugs (risk of hypotension); drugs that prolong the QT interval (amiodarone, chloroquine, erythromycin, fluconazole, mefloquine, pentamidine, quinine, etc.).
- Avoid alcohol during treatment (increased risk of adverse effects).
- Pregnancy: re-evaluate whether the treatment is still necessary; if it is continued, use the lowest effective dose. Observe the neonate the first few days (risk of agitation, tremors, hypertonia/hypotonia, respiratory difficulties, sleeping disorders, etc.) if the mother was under treatment in the 3rd trimester. If treatment starts during pregnancy, preferably use haloperidol.
- Breast-feeding: if absolutely necessary, use the lowest effective dose.
Remarks
- Do not crush tablets (risk of contact dermatitis).
Storage
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– Below 25 °C