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Due to the numerous and potentially severe adverse effects of risperidone, patients should be kept under close surveillance.
Therapeutic action
- Atypical antipsychotic
Indications
- Acute and chronic psychosis and acute manic episode, in the event of intolerance or treatment failure with other antipsychotics (preferably use haloperidol for these indications)
Forms and strengths
- 1 mg and 2 mg tablets
Dosage
Acute or chronic psychosis
- Adult: 1 mg 2 times daily. Gradually increase up to 3 mg 2 times daily if necessary (max. 10 mg daily).
Acute manic episode
- Adult: 2 mg once daily. Increase in increments of 1 mg per week if necessary (max. 6 mg daily).
Reduce the dose by half (initial dose and increments) in older patients and in patients with hepatic or renal impairment (max. 4 mg daily).
Duration
- Acute psychosis: at least 3 months
- Chronic psychosis: at least one year
- Manic episode: 8 weeks after remission of symptoms
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), Parkinson's disease and history of neuroleptic malignant syndrome.
- Administer with caution and carefully monitor use in older patients, patients with hypokalaemia, hypotension, renal or hepatic impairment, history of seizures.
- May cause: drowsiness (caution when driving/operating machinery), insomnia, headache, extrapyramidal symptoms, agitation, anxiety, orthostatic hypotension, weight gain, hyperprolactinaemia, sexual dysfunction; neuroleptic malignant syndrome (unexplained hyperthermia with neuromuscular disorders), rare but requiring immediate treatment discontinuation.
- In case of extrapyramidal symptoms, try reducing the dose of risperidone 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.);
- fluoxetine, paroxetine, sertraline, verapamil (increased plasma concentrations of risperidone);
- carbamazepine, rifampicin, phenobarbital, phenytoin (decreased plasma concentrations of risperidone);
- 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, do not exceed 6 mg daily.
Storage
– Below 25 °C