From the Guidelines
Before initiating lithium therapy, a comprehensive baseline assessment should be performed, including complete blood cell counts, thyroid function tests, urinalysis, blood urea nitrogen, creatinine, and serum calcium levels, as well as a pregnancy test in female adolescents. This assessment is crucial for ensuring the safe and effective use of lithium, as it can have significant effects on various organ systems, particularly the kidneys and thyroid 1.
Key Components of Baseline Assessment
- Complete blood cell counts to assess for any underlying hematological abnormalities
- Thyroid function tests, including TSH and free T4, to evaluate thyroid function
- Urinalysis to assess renal function and detect any potential renal abnormalities
- Blood urea nitrogen and creatinine levels to evaluate renal function
- Serum calcium levels to assess for any electrolyte imbalances
- Pregnancy test in female adolescents to prevent potential fetal harm
Importance of Baseline Assessment
Regular monitoring of lithium levels and these parameters will be necessary throughout treatment to ensure safety and efficacy, as lithium has a narrow therapeutic window 1. A thorough medical history focusing on cardiovascular disease, renal impairment, thyroid disorders, and medication use is also essential to identify potential risks and contraindications. Weight and vital signs should be documented, and baseline neurological status should be assessed, as lithium can cause tremor and other neurological effects. Additionally, a psychiatric evaluation to establish baseline mood symptoms and cognitive function is important for monitoring treatment response.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION ... Serum levels should be determined twice per week during the acute phase, and until the serum level and clinical condition of the patient have been stabilized. ... Blood samples for serum lithium determination should be drawn immediately prior to the next dose when lithium concentrations are relatively stable (i.e., 8-12 hours after the previous dose). The baseline assessment for lithium includes determining the serum lithium level, which should be drawn immediately prior to the next dose when lithium concentrations are relatively stable (i.e., 8-12 hours after the previous dose) 2.
- The desirable serum lithium levels are:
- 1 to 1.5 mEq/L during the acute phase
- 0.6 to 1.2 mEq/L for long-term control Key points to consider are individualized dosage and regular monitoring of the patient’s clinical state and of serum lithium levels 2.
From the Research
Baseline Assessment for Lithium
The baseline assessment for lithium treatment includes various laboratory tests to monitor renal, thyroid, and parathyroid function.
- Renal function tests:
- Thyroid function tests:
- Parathyroid function tests:
Recommendations for Baseline Assessment
It is recommended to perform these tests at baseline and annually, or more frequently in certain patient populations, such as middle-aged females (≥50 years), patients with a family history of thyroid disease, and those positive for thyroid auto-antibodies 6.