- Risperdal is known to cause tardive dyskinesia in some people. Tardive dyskinesia is a condition in which facial tics and muscle spasms are present and can become permanent.
- Risperdal may cause low blood pressure. Dizziness after standing up is the most frequent symptom.
- Risperdal and its class of drugs have become associated with an increased risk of developing high blood sugar or diabetes. Symptoms of high blood sugar include increased thirst or urination and dry mouth.
- Risperdal is known to change the metabolism, with weight gain a common side effect.
- Neuroleptic malignant syndrome is a side effect of Risperdal. This condition includes susceptibility to heat, sweating, irregular heartbeat, confusion and muscle aches.
- According to the Physicians Desk Reference, other side effects of Risperdal include "agitation, anxiety, constipation, dizziness, hallucination, headache, indigestion, insomnia, rapid or irregular heartbeat, restlessness, runny nose, sleepiness, vomiting, and weight change."
