Monitoring the Kidneys with Lithium Use

The latest edition of the British Journal of Psychiatry ( August 2008 ) is packed with interesting articles. I particularly like the debate on community treatment orders at the beginning. There are also editorials, research papers, book reviews, a short report and even a poem written by a doctor.

One of the editorials is by Professor Richard Morriss and Dr Benson Benjamin on the subject of a now routinely reported measure of kidney function – the estimated Glomerular Filtration Rate. The eGFR is calculated by using the creatinine levels in the bloodstream and also taking into consideration age, sex and ethnicity to produce a number which is expressed as output (milliLitres) per minute per unit of surface area. The glomerular filtration rate reflects how well the kidneys are filtering substances from the blood.

The National Service Frameworks are high level strategies for improving patient care over the long term but focus on a specific area of care. Examples of frameworks include those for mental health, blood pressure, kidney disorders and chronic neurological conditions. Within the NSF for kidney disorders there is guidance on the use of medications which interacts with the kidneys and which can cause potential harm to the kidneys and the advice to use the eGFR for monitoring their use. One of the really neat points about using the eGFR is that it is predicted that this will catch people much earlier, before they go into the more severe stages of renal failure. Thus at a population level it should increase life expectancy in those that are developing kidney problems.

In a rather tenuous way we have now arrived at Lithium. Lithium is a very useful drug in psychiatry as it has been shown to effectively control mood in both unipolar depression and bipolar depression. Not only can it help to stabilise mood, but it has also been shown to reduce suicide. One of the drawbacks of Lithium however is that it can cause some harm to the kidneys but in a very small percentage of people. This is one of the reasons why people taking Lithium are monitored with blood tests (as well as to ensure that the Lithium is in the therapeutic range).

In the article the recommendations of the UK Consensus Conference on Early Chronic Kidney Disease (that’s a bit of a mouthful!) have been tailored to Lithium thus giving psychiatrists some very useful guidelines for managing their patients on Lithium. The article emphasises the need to keep abreast of changes in different fields that impact on psychiatry.

References

Morriss R and Benjamin B. Editorial: Lithium and eGFR: a new routinely available tool for the prevention of chronic kidney disease. 193. pp93-95. 2008.

Disclaimer

The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor.