Risperidone and Autism Ranking: Mildly Hazardous Very strong positive evidence

Risks and Safety


According to the American Society of Health-System Pharmacists (2017), risperidone can cause a number of side effects including: “nausea; vomiting; diarrhea; constipation; heartburn; dry mouth; increased saliva; increased appetite; weight gain; stomach pain; anxiety; agitation; restlessness; dreaming more than usual; difficulty falling asleep or staying asleep; breast enlargement or discharge; late or missed menstrual periods; decreased sexual ability; vision problems; muscle or joint pain; dry or discolored skin; difficulty urinating; dizziness, feeling unsteady, or having trouble keeping your balance.”

More seriously it can sometimes cause “fever; muscle stiffness; falling; confusion; fast or irregular pulse; sweating; unusual movements of your face or body that you cannot control; faintness; seizures; slow movements or shuffling walk; rash; hives; itching; difficulty breathing or swallowing; painful erection of the penis that lasts for hours.”

Even more seriously risperidone can cause significant side effects in some older adults with dementia.

“Studies have shown that older adults with dementia (a brain disorder that affects the ability to remember, think clearly, communicate, and perform daily activities and that may cause changes in mood and personality) who take antipsychotics (medications for mental illness) such as risperidone have an increased risk of death during treatment. Older adults with dementia may also have a greater chance of having a stroke or ministroke during treatment.”


There are some contraindications (something which makes a particular treatment or procedure potentially inadvisable) for risperidone. For example, according to American Society of Health-System Pharmacists (2017), risperidone should be used with caution in people who

  • are already using or planning to use one of the following medications or dietary supplements: “antidepressants; carbamazepine (Tegretol); cimetidine (Tagamet); clozapine (Clozaril); dopamine agonists such as bromocriptine (Parlodel), cabergoline (Dostinex), levodopa (Dopar, Larodopa), pergolide (Permax), and ropinirole (Requip); medications for anxiety, high blood pressure, or seizures; other medications for mental illness; paroxetine (Paxil); phenobarbital (Luminal, Solfoton); phenytoin (Dilantin); quinidine (Quinaglute, Quinidex); ranitidine (Zantac); rifampin (Rifadin, Rimactane); sedatives; sleeping pills; tranquilizers; and valproic acid (Depakote, Depakene).”
  • “use or have ever used street drugs or large amounts of alcohol; have ever overused prescription medications; have or have ever had Parkinson's disease (PD; a disorder of the nervous system that causes difficulties with movement, muscle control, and balance); dyslipidemia (high cholesterol levels); a low level of white blood cells in your blood or a decrease in white blood cells; difficulty swallowing; trouble keeping your balance; breast cancer; angina (chest pain); irregular heartbeat; high or low blood pressure; heart failure; a heart attack; a stroke; seizures; heart, kidney or liver disease; or if you or anyone in your family has or has ever had diabetes.”

Please see American Society of Health-System Pharmacists (2017), for a full list of potential hazards and contraindications.

03 Aug 2018
Last Review
01 Jul 2018
Next Review
01 Jul 2021