Psychiatric Times
August 2005
Vol. XXII
Issue 9
Since the 1970s, lithium(Drug information on lithium) (Eskalith, Lithobid) has been a mainstay of treatment for bipolar disorder (BD) and an effective augmentation strategy for treatment-resistant unipolar depression. Lithium, long before lamotrigine(Drug information on lamotrigine) (Lamictal), olanzapine (Zyprexa) and aripiprazole(Drug information on aripiprazole) (Abilify), received the U.S. Food and Drug Administration's approval for the maintenance treatment of BD. Despite lithium's efficacy, many psychiatrists find regular monitoring of lithium blood levels to be burdensome for their patients and for themselves. But that burden may soon ease. Recently, the FDA approved an office-based test that permits psychiatrists or their clinical staff to obtain a patient's lithium levels in minutes.
Lithium is a benchmark drug, but the amount that is needed to be effective is slightly less than toxic levels, so you have got to monitor levels and keep them in therapeutic ranges, somewhere between 0.4 mEq/L and 1.4 mEq/L, said William Glazer, M.D., president and chief medical officer of ReliaLAB, Inc., the New Jersey company that developed the testing system. This "point-of-care" test is available to psychiatry and can be likened to glucose monitoring devices being used in diabetes care, said Glazer, who is also associate clinical professor at Massachusetts General Hospital and Harvard Medical School.
During a recent press briefing at the 158th Annual Meeting of the American Psychiatric Association in Atlanta, Glazer explained how that test system provides quantitative results from a few drops of blood obtained from a finger stick. The blood is put into a blood separator device. The processed plasma is added to a prefilled reagent cuvette; and the cuvette is placed in a reader to obtain a patient's lithium level. "All of this takes between two and five minutes," he said. "You can do an assessment of your patient on the spot."
At the APA meeting, Glazer et al. (2005) also presented a new research poster on a study of the accuracy and reliability of the test system that replicated findings of a previous study (Glazer et al., 2004). Investigators from Uptown Research Institute in Chicago performed the clinical trials that led to the FDA's approval.
"We have a large number of patients on lithium in our practice. We selected 56 of these patients to have a triangular blood test done," said poster co-author Michael J. Reinstein, M.D., of the Uptown Research Institute. The patients on oral lithium contributed 88 matched data points, for which blood lithium levels were estimated by the instant test and two different laboratories that employed atomic absorption spectrophotometry (Glazer et al., 2005). Reinstein reported that the new office-based test for lithium levels was as accurate as those tests used in commercial laboratories.
Goodwin's Perspective
