How to use Risperdal. Take this medication by mouth with or without food as directed by your doctor, usually once or twice daily. If you are using the liquid form of this medication, carefully. Risperdal is available in liquid and tablet form as well as an orally disintegrating tablet. It is usually taken once or twice a day with or without food. Take this medication around the same time. Find information about common, infrequent and rare side effects of Risperdal Oral. Taking Risperdal with other drugs that make you sleepy or slow your breathing can cause dangerous or life-threatening side effects. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures. While Risperdal can be effective in treating these disorders, you should be aware of the potential side effects before starting treatment. While many of the side effects are manageable, others may be serious and, in rare cases, life-threatening. Your doctor should also know if you ever developed severe side effects from a medication to treat mental illness. Tell your doctor if you are pregnant, particularly if you are in your third trimester. Along with its needed effects, risperidone (the active ingredient contained in Risperdal) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. My psychiatrist was very convincing. Risperdal (Risperidone) was going to fix my problem, he raved about the medication's benefits and the side effects were almost whispered under his breath like they don't mean a thing. Because some Risperdal side effects such as enlarged breast tissue, obesity, heart problems and diabetes can be serious, experts recommend alternative treatments for children who are stable but experiencing aggression or irritability. Our Risperdal Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. articles. This is not a complete list of side effects and others may occur.