"for those who has been having anemia or low blood pressure problem (esp ladies), quetiapine lowered blood pressure and blood sugar level and that causes me feel light-headed, dizziness, fainting spell and developed slight vertigo. check your blood pressure and discuss with your doctor before taking quetiapine. i&#039;ve stopped taking it for more than 1 week and my symptoms of dizziness and fainting spells slowly subsided."