Seroquel (quetiapine fumarate), an oral medication for the management of the manifestations of psychotic disorders (including schizophrenia and bipolar mania), was cleared by the FDA for marketing on September 29, 1997. Seroquel is a new "atypical" antipsychotic agent in a new chemical class called dibenzothiazepine derivatives. Seroquel is manufactured by AstraZeneca Pharmaceuticals.

Findings from extensive clinical trials have shown Seroquel to be effective in the treatment for schizophrenia - both positive (e.g., delusions, thought disorder, and hallucinations) and negative (e.g., social withdrawal, lack of energy, apathy, and reduced ability to express emotion) symptoms of schizophrenia. Seroquel affects a broad range of neurotransmitter receptors, including serotonin receptors. In comparative clinical trials, Seroquel has been shown to be as effective as standard antipsychotic agents, such as chlorpromazine (Thorazine) and haloperidol (Haldol).

Advantages of Seroquel Over Other Antipsychotics

The reported clinical studies show that Seroquel has "full antipsychotic activity" and the advantage of fewer or less severe motor side effects. In test groups unwanted reactions were usually rated mild to moderate, and the active-treatment groups did not differ from the placebo group in scores measuring akathisia (complaints of restlessness accompanied by fidgety movements) or involuntary movements. Tremor did not develop in any patient receiving active treatment.

Seroquel Dosage

Seroquel is available by prescription throughout the U.S. in strengths of 25 mg (peach), 100 mg (yellow), and 200 mg (white) tablets. In clinical trials, it was effective in a dose range of 150 mg/day to 750 mg/day. A maximum therapeutic effect was seen at 300 mg/day in a dosing trial. In other studies, doses in the range of 400-500 mg/day were effective. Taking Seroquel two to three times a day is recommended.

Seroquel usually starts working in about one and a half hours. The medication may take longer to exhibit beneficial effects in some people due to symptoms and other factors.

Side Effects of Seroquel

Reported side effects of Seroquel are similar to those seen with other antipsychotics. These include sleepiness; hypotension (abnormally low blood pressure); digestive problems (constipation, dry mouth, indigestion); and dizziness. Such effects are usually seen when the medication is first taken. They are mild and generally improve without specific treatment. Seroquel should be used with particular caution in patients with known cardiovascular disease, cerebrovascular disease, or conditions associated with hypotension.

Warnings

If you are pregnant, plan to become pregnant, or breastfeeding, discuss the potential risks of this or any medication with your doctor.

Like other atypical antipsychotics, Seroquel has been linked to causing diabetes and hyperglycemia. Patients using Seroquel, especially those with risk factors associated with diabetes should have their blood sugars monitored.

Elderly individuals may need to take a lower dose than younger patients.

Remember, always follow your physician's recommendations on how to take your medication. Even if you are taking one of the following substances, continue taking your medication as prescribed and consult your physician. Also, if you are taking any herbal remedies, vitamins, and/or over-the-counter medications, be sure to tell your physician. The following section offers some, but not necessarily all, of the possible drug interactions.

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