Side effects of risperidone include: common adverse reactions: insomnia, anxiety, agitation, headache, dry mouth; less common adverse reactions are: drowsiness, fatigue, decreased concentration, constipation, dyspepsia, nausea, vomiting, abdominal pain, blurred vision, abnormal penile erection, erectile difficulty, weak ejaculation, sexual indifference, urinary incontinence, rhinitis, rash, and other allergic reactions; may cause extrapyramidal symptoms such as: muscle tension, tremor, rigidity, salivation, bradykinesia, inability to sit still, and acute dystonia; occasional symptoms of (postural) hypotension, (reflex) tachycardia, or hypertension; weight gain, edema, and elevated transaminase levels; in foreign clinical studies, risperidone tablets have been reported in elderly patients (mean age 85 years) with dementia-related psychiatric symptoms The incidence of cerebrovascular adverse events, such as stroke and transient ischemic attacks, including death, was significantly higher than that of placebo; elderly patients with dementia-related psychiatric symptoms may be at increased risk of cerebrovascular adverse events and need to be aware of them; water intoxication may occasionally occur due to patient irritability or dysregulation of antidiuretic hormone secretion; it causes an increase in plasma prolactin concentrations, with associated symptoms such as: breast overflow, man gynecomastia, menstrual disorders, amenorrhea; occasional delayed dyskinesia, malignant syndrome, dysregulation of body temperature, and seizures; mildly decreased neutrophil and/or platelet counts have been reported in isolated cases. In clinical practice, risperidone is one of the most used drugs in children and adolescents with schizophrenia. Side effects do not always occur as indicated in the drug’s instructions. Clinical experience has shown that the most common side effects of risperidone include weight gain, extrapyramidal symptoms, and elevated prolactin.