From the Guidelines
Ongoing baseline assessment for lithium should include regular monitoring of serum lithium levels, renal and thyroid function, and urinalyses every 3-6 months, as recommended by Kowatch and DelBello 1. This monitoring is crucial to ensure the safe and effective use of lithium, given its narrow therapeutic index and potential effects on multiple organ systems. The key components of this assessment include:
- Serum lithium levels, which should be drawn 12 hours after the last dose to accurately reflect trough levels
- Renal function tests, such as creatinine, blood urea nitrogen, and serum calcium levels, to monitor for potential nephrotoxicity
- Thyroid function tests, including TSH and free T4, to assess for potential thyroid dysfunction
- Urinalyses to monitor for changes in renal function or potential lithium toxicity Regular clinical assessment for side effects and toxicity symptoms is also essential, including monitoring for tremor, cognitive changes, gastrointestinal symptoms, and neurological signs. Additionally, weight and blood pressure should be monitored at each visit, as lithium can affect these parameters, particularly with long-term use 1. By following this monitoring schedule, clinicians can promptly identify potential issues and adjust treatment as needed to minimize the risk of complications and optimize patient outcomes.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION ... Regular monitoring of the patient’s clinical state and of serum lithium levels is necessary. 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. ... Serum lithium levels in uncomplicated cases receiving maintenance therapy during remission should be monitored at least every two months. N.B.: 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 ongoing baseline assessment for lithium includes:
- Regular monitoring of the patient's clinical state
- Serum lithium levels determination
- At least every two months in uncomplicated cases receiving maintenance therapy during remission
- Twice per week during the acute phase, until the serum level and clinical condition of the patient have been stabilized
- Blood samples should be drawn 8-12 hours after the previous dose 2
From the Research
Ongoing Baseline Assessment for Lithium
The ongoing baseline assessment for lithium is crucial to monitor its potential side effects and toxicity. Some of the key aspects to consider include:
- Renal function: Lithium can cause adverse effects on the kidneys, including interstitial nephritis, nephrogenic diabetes insipidus, and reduction in glomerular filtration rate 3, 4, 5, 6, 7.
- Thyroid function: Lithium can cause hypothyroidism, which is relatively common and easily diagnosed and treated 3, 4.
- Parathyroid function: Lithium can cause hyperparathyroidism, which is a relatively more recently recognized phenomenon 3, 4.
- Cognitive function: Lithium can cause cognitive impairment, which can be distressing to patients and difficult to manage 3, 6.
- Weight gain: Lithium can cause weight gain, which can be a significant concern for patients 3, 6.
Monitoring Strategies
To minimize the side effect burden and ensure safe and effective use of lithium, the following monitoring strategies are recommended:
- Regular blood tests to monitor renal, thyroid, and parathyroid function 3, 4, 7.
- Urine tests to monitor urine concentrating ability and albuminuria 7.
- Serum creatinine concentration and prediction equations to estimate glomerular filtration rate (GFR) 7.
- Regular assessment of cognitive function and weight gain 3, 6.
Special Considerations
Certain patient populations may be at greater risk of lithium-induced side effects, including: