Lithium

Chemical Pathology

Lithium is used in the treatment of bipolar disorder as a modulator of neurotransmission.
Lithium levels are indicated for routine therapeutic monitoring; to check compliance; if there is a deterioration in response to treatment; if renal function is fluctuating; when drugs that interact are co-prescribed (e.g. diuretics, ACE inhibitors and NSAIDs), or when toxicity is suspected.
Refer to NICE guideline CG185 Assessment and Management of Bipolar Disorder for information on monitoring of lithium therapy.

Samples should be collected 12 hours after the last dose,
Minimum re-sampling time is 1 week after any change in dose.
Lithium levels should be checked every 3 months and thyroid and renal function every 6 months as a minimum (but check latest NICE guidelines for up to date information)

For adults, 5 ml of blood taken into a narrow gold top tube (or rust top for the Acute Unit)

*** DO NOT USE LITHIUM HEPARIN TUBES FOR THIS TEST ***

Send at ambient temperature to the laboratory on day of sample collection. If unavoidable, samples can be stored refrigerated overnight.

Relevant clinical details including other relevant medication, time of last dose and time of sample.

NICE Guidelines for Bipolar Disorder CG185 (Sept 2014):
Therapeutic Range for Lithium
Aim for: 0.6 – 0.8 mmol per litre normally.
Psychiatrists may recommend lower or higher target ranges for individual patients.
Therapeutic range applies to serum Lithium in a sample taken 12 hours after the Lithium dose.

NICE Guideline CG185 for Bipolar Disorder
For National Patient Safety Association information on lithium including links to patient booklet please visit the NPSA page on Safer lithium therapy.
To learn more about lithium visit Lab Tests Online
To learn more about bipolar disorder visit the Royal College of Psychiatrists website