Examkin

Question

Difficulty: MediumMonitoring and Treatment Evaluation

During an interdisciplinary rounds discussion on the psychiatric ward, the care team plans the discharge of a 35-year-old female who was recently stabilized from an acute manic episode. The patient was successfully transitioned to maintenance lithium carbonate therapy over the past ten days. Her current serum lithium trough level is within the therapeutic window. To appropriately monitor for the most common long-term adverse effects of this pharmacotherapy, which of the following laboratory parameters should be periodically evaluated in the outpatient setting? (Select all that apply)

  1. Thyroid-stimulating hormoneAnswer
  2. Serum creatinineAnswer
  3. C
    Alanine aminotransferase
  4. D
    Absolute neutrophil count
  5. E
    Hemoglobin A1c

Answer

The correct parameters to monitor routinely are thyroid-stimulating hormone and serum creatinine.
Lithium is a foundational mood stabilizer that carries specific long-term toxicity risks. It is primarily excreted by the kidneys and can induce chronic tubulointerstitial nephropathy over time, which can ultimately lead to chronic kidney disease. Therefore, renal function must be tracked via periodic serum creatinine measurements. Additionally, lithium frequently interferes with thyroid hormone synthesis and release, leading to hypothyroidism, which mandates regular monitoring of thyroid-stimulating hormone (TSH). Calcium levels are also often checked due to the risk of hyperparathyroidism, though renal and thyroid panels remain the most critically emphasized.

Step-by-Step Solution

1
Identify the prescribed medication and its clearance mechanism.
The medication is lithium, which is not metabolized by the liver but is entirely excreted by the kidneys.
Understanding the pharmacokinetic profile helps predict organ-specific toxicities.
2
Determine the primary organ systems affected by long-term lithium toxicity.
Long-term lithium use is predominantly associated with renal toxicity (nephrogenic diabetes insipidus, tubulointerstitial nephropathy) and thyroid dysfunction (hypothyroidism, goiter).
These established toxicities dictate the required laboratory surveillance protocols.
3
Select the appropriate screening tests corresponding to the affected organ systems.
Serum creatinine (renal function) and thyroid-stimulating hormone (thyroid function) should be periodically evaluated.
Guideline-concordant care mandates tracking these specific parameters to detect silent adverse effects early.

Key Concept

Long-term outpatient monitoring for lithium therapy requires periodic assessment of renal function (serum creatinine, BUN) and thyroid function (TSH) due to the risks of tubulointerstitial nephropathy and hypothyroidism.
Rate this question

Topics

Monitoring and Treatment Evaluation

More questions from this topic