Risperdal

What is it?

An antipsychotic and benzisoxazole derivative available as film-coated, scored tablets in 6 strengths, all containing risperidone. Red, oblong tablets contain 0.5mg, coded Ris/0.5; white, oblong contain 1mg, coded Ris/1; orange, oblong contain 2mg coded Ris/2; yellow, obling contain 3mg, coded Ris/3; green, oblong contain 4mg, coded Ris/4; yellow, round tablets contain 6mg, coded Ris/ 6. Also, RISPERDAL LIQUID, a solution containing 1mg of risperidone per ml supplied with pipette. Also, RISPERDAL CONSTA, available as sustained-release powder in vial with solvent in syringe, in 3 strengths containing 25mg, 37.5mg and 50mg of risperidone, for intramuscular injection.

Medical Uses

Schizophrenia and other psychoses.

Dosage

Adults and children aged over 15 years, tablets and liquid, start with 2mg as single dose on 1st day increasing to 4mg as single dose on 2nd day. Then, increase as required to usual dose in order of 4 to 6mg once each day to a maximum single daily dose of 16mg. Some patients may require lower doses and slower increases in dosage. Elderly, start with 0.5mg, increasing by 0.5mg increments to 1 to 2mg twice each day. Risperdal Consta, adults aged over 18 years, (patients who have not received risperidone before should first be treated with oral preparation to assess response). Patients who are stable on 4mg or less of risperidone taken by mouth, 25mg by deep intramuscular injection into buttock every 2 weeks. Dose can then be increased, if required allowing at least 4 week intervals, to 37.5mg every 2 weeks and then 50mg every 2 weeks, as maximum dose. Patients who are stable on higher oral doses of risperidone can be started on 37.5mg every 2 weeks, increasing as above to a maximum dose of 50mg every fortnight, if required. Elderly patients, 25mg by deep intramuscular injection into buttock every 2 weeks, with additional oral dose during first 3 weeks after initial injection, if necessary.

Special Care

Pregnancy, breastfeeding, epilepsy, disease of kidney, liver or heart and blood vessels, Parkinsonism, if driving or operating machine.

Avoid Use

Children.

Possible Drug and Food Interactions

Levodopa, dopamine agonists, carbgmazeeine.

Known Side Effects

Low blood pressure, rapid heartbeat rate, agitation, abnormal breast enlargement, urinary incontinence, sexual disorders, priapsm (abnormal, persistent, painful erection), anxiety, insomnia, headache, fatigue, sleepiness, dizziness, weight gain, gastrointestinal upset, rash, rhinitis (irritation and runny nose), blurred vision, poor concentration.