8 Feb 2008
Rapid Cycling. About 15% of patients with bipolar disorder have a temporary, complicated phase known as rapid cycling. With this phase the manic and depressive episodes alternate at least four times a year and, in severe cases, can even progress to several cycles a day. Rapid cycling tends to occur more often in women and in those with bipolar II. Typically, rapid cycling starts in the depressive phase, and frequent and severe episodes of depression may be the hallmark of this event. This phase is difficult to treat, particularly since antidepressants can trigger the switch to mania and set up a cyclical pattern.
Treatment Guidelines for Mixed Episodes and Rapid Cycling
The first step in treating rapid cycling is to try to identify and resolve other factors, such as drug abuse or hypothyroidism, which may have caused this condition. Many patients may require a combination of medications to control rapid cycling.
- Antidepressants may prompt rapid cycling and should be tapered off.
- Lithium or valproate is a first-line treatment for rapid cycling.
- Lamotrigine is an alternative treatment for rapid cycling.
- Atypical antipsychotics (olanzapine, aripiprazole, ziprasidone, risperidone) are approved to treat mixed episodes. These drugs are used either alone or in combination with lithium or valproate.
- One biological mechanism involved with rapid cycling is an excessive influx of calcium into brain cells. Cardiovascular drugs called calcium channel blockers may be beneficial for ultra-rapid cycling.
- Low thyroid (hypothyroidism) is involved in some cases of rapid cycling. In these cases, levothyroxine, a synthetic derivative of the thyroid hormone T4 (thyroxine), has helped stabilize rapid-cycling patients.
- Electroconvulsive therapy can be useful in emergency situations.
In addition, other measures should be taken:
- Patients should avoid anti-anxiety drugs, alcohol, caffeine, and stimulants.
- Patients should avoid exposure to bright light.
- All efforts should be made to help the patient sleep normally
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