The pharmaceutical company AstraZenica is the maker Seroquel, which is the brand name for the drug quetiapine. According to the complete prescribing information for the drug provided by AstraZenica, the Federal Drug Administration (FDA) has approved Seroquel for the treatment of schizophrenia and bipolar disorder in both adolescents and adults. AstraZenica reports that there are severe possible complications that may occur as a result of a Seroquel overdose.
Changes in Consciousness
AstraZenica describes drowsiness and sedation as a possible overdose symptom. A person who has overdosed on Seroquel may feel excessively sleepy and become unconscious. MedlinePlus confirms drowsiness as a symptom of Seroquel overdose, and also includes fainting among the possible symptoms.
Tachycardia
Another symptom of Seroquel overdose is tachycardia. According to the Mayo Clinic, tachycardia is a faster than normal heart rate. The Mayo Clinic describes a normal heart rate as 60-100 times per minute, and thus tachycardia is defined as a rate above 100 beats per minute. Tachycardia may have no other symptoms beside a "racing heart"; however, tachycardia may cause heart damage, and result in stroke and/or cardiac arrest.
Hypotension
A third symptom of Seroquel overdose is hypotension, or low blood pressure. Information from the Merck Manuals indicates that low blood pressure may result in not enough blood reaching all parts of the body. Merck also reports that low blood pressure may result in dizziness and fainting. In fact, severe hypotension may lead to brain damage.
Hypokalemia
Though only one case has been reported, AstraZenica reports that hyperkalemia is a risk of Seroquel overdose. MedlinePlus reports that hyperkalemia is when the levels of potassium in the blood become elevated. Normal levels of potassium in the blood are important for multiple bodily processes, including muscle contraction, metabolism, and maintenance of chemical and electrical processes. Excess potassium in the blood may be accompanied by no symptoms or by irregular heartbeat, nausea and/or cardiac arrest.
