Risperidone is a selective monoaminergic antagonist having a high affinity for serotoninergic 5-HT2 and dopaminergic D2 receptors. Risperidone binds also to alpha1 adrenergic receptors and with lower affinity, to H1 histamine and alpha2 adrenergic receptors. Risperidone has no affinity for cholinergic receptors. Risperidone, as a potent D2 antagonist, improves the positive symptoms of schizophrenia but causes less depression of motor activity. Balanced central serotonin and dopamine antagonism may reduce extrapyramidal side effect liability and extend the therapeutic activity to the negative and affective symptoms of schizophrenia.
Frenia 1 Tablet
Acute manic episodes of bipolar disorder:
Adult: Initially, 2-3 mg once daily. May increase by 1 mg daily at intervals of at least 24 hr. Max: 6 mg daily.
Elderly: Initiate with lower doses.
Adult: Initially, 2 mg daily, may increase to 4 mg daily on the 2nd day, adjusted further in increments or decrements of 1-2 mg daily at wkly intervals. Doses may be given in 1-2 divided doses. Maintenance: 4-6 mg daily. Max: 16 mg/day.
Elderly: Initially, 0.5 mg bid gradually increased in increments of 0.5 mg bid. Maintenance: 1-2 mg bid.
Adult: Give oral risperidone for a few days to assess tolerability prior to initiating inj. For patients not stabilised on oral risperidone: 25 mg every 2 wk. Patients stabilised on oral risperidone for at least 2 wk in doses ≤4 mg daily: 25 mg every 2 wk. Patients stabilised on oral risperidone for at least 2 wk in doses >4 mg daily: 37.5 mg every 2 wk. Continue oral risperidone for the 1st 3 wk after the 1st inj.
Elderly: Max dose: 25 mg every 2 wk.