Risperdal^® (risperidone) is a medicine that is approved to treat schizophrenia, bipolar disorder, and irritability due to autism. The prescription medication works by blocking or lessening the effects of several chemicals in the brain. Risperdal comes in tablet form and is usually taken once or twice a day. For people who have difficulty swallowing tablets, Risperdal is also available as a liquid, an orally disintegrating tablet, and as a long-acting injection. Some of the factors that can affect the dose of Risperdal that your healthcare provider prescribes include the medical condition being treated, your age and weight, other medical conditions you may have, and other medications you may be currently taking.