[Lithium levels need to be monitored: discrepancies between guidelines and practice]

Since lithium can affect the thyroid gland and the kidneys, it is important to perform regular checks on levels of lithium, creatinine and thyroid-stimulating hormone (TSH).

To investigate whether psychiatrists and general practitioners (GPs) perform the required checks twice a year on the levels of lithium, creatinine and tsh in accordance with the Dutch guidelines on bipolar disorder as laid down in 2001.

The study was based on data that the clinical-chemical laboratory had regarding the lithium checks performed in 2004 in GPs' practices or by the mental health authority in Apeldoorn and the surrounding area. About 250,000 people live in this region.

Some of the psychiatrists (11%) and GPs (about 25%) did not check lithium levels as frequently as recommended in the guidelines of 2001. The GPs checked significantly less frequently that the psychiatrists. Both the GPs and the psychiatrists monitored creatinine and TSH less frequently than recommended in the guidelines, creatinine was monitored in 65.8 and 61.2% and TSH in 68.3 and 58% respectively. CONCLUSION We recommend that a warning system be installed in the laboratory which will alert the doctor when a patient has missed a check. Another suggestion is that lithium should be prescribed only by psychiatrists, and not by GPs.