Risperidone

Risperidone, marketed in Australia under the brand name Risperdal and various generic brands, is a prescription medicine used to treat patients with behavioural disorders.

We received 22 adverse event reports in 2024 involving the overdose of risperidone oral solution in Australian patients under 18. Most reports involved accidentally administering more than the prescribed dose, leading to adverse effects and hospitalisation of the child. No deaths were reported in this group.

We carried out an investigation and found that these errors were often due to:

• misunderstanding of dosing instruction
• incorrect use of dosing syringe
• administration by alternative caregivers, such as babysitters or an extended family member.

As a result, we required the pharmaceutical company supplying Risperdal oral liquid to update the Product Information (PI) and Consumer Medicines Information (CMI) with clearer dosing instructions and visual aids. Generic brands will be required to update their PIs and CMIs with similar information.

What patients or their carer should do

Before taking or giving risperidone, you should:

• familiarise yourself on how to use the supplied measuring syringe
• double check the instruction label to ensure you are drawing up the correct dose
• if you are unsure, refer to the PI and CMI of your risperidone product or speak with a health professional.

What health professionals should do

When counselling risperidone patients or caregivers, health professionals should:

• ensure all caregivers are aware of the correct dosing instructions
• provide clear explanation on how to measure the exact dose using the supplied syringe
• remind caregivers to read the dosing label carefully before administration and confirm their understanding, especially with first-time users.

For more detailed information written for health professionals, including the full text of additional warning, see this Medicines Safety Update article.