Seroquel is associated with an increased risk of developing high blood sugar, which on rare occasions can lead to coma or death. See your doctor right away if you develop signs of high blood sugar, including dry mouth, unusual thirst, increased urination, and tiredness. If you have diabetes or have a high risk of developing it, see your doctor regularly for blood sugar testing
A rare side effect of seroquel is that it may cause tardive dyskinesia, a condition characterized by uncontrollable muscle spasms and twitches in the face and body. This problem can be permanent, and appears to be most common among older adults, especially women
Particularly during the first few days of therapy, seroquel can cause low blood pressure, with accompanying dizziness, fainting, and rapid heartbeat.
Seroquel also tends to cause drowsiness, especially at the start of therapy, and can impair your judgment, thinking, and motor skills.