Clinical implications. This is a single case study. However, it is important for clinicians treating patients with lithium carbonate to regularly order laboratory testing, including for lithium levels, PTH, and calcium, to detect early signs of complications from treatment, including hyperparathyroidism and hypercalcemia.7 These levels could be obtained every 6 months. If a patient’s PTH levels are >70 pg/mL and calcium levels are >11.0 mg/dL, it would be prudent to refer him/her for further medical evaluation. Additionally, it would be helpful to counsel the patient about considering alternative medication and adjunct mental health treatment. At some future point, it could be useful for the clinician and his/her patient to explore the idea of parathyroid surgery.
In addition to chronic lithium use, other causes of hyperparathyroidism include an adenoma on a gland, hyperplasia of ≥2 parathyroid glands, a malignant tumor, severe calcium deficiency, severe vitamin D deficiency, chronic renal failure, and (rarely) an inherited gene that causes hyperparathyroidism.
How I’m doing today. Currently, I am euthymic and in a happy marriage. My laboratory workup in May 2020 included glucose 107 mg/dL, Ca++ 9.5 mg/dL, eGFR 61 mL/min, PTH 32 pg/mL, lithium 0.3 mmol/L (300 mg twice daily), and TSH 1.79 mIU/L. A comprehensive metabolic panel, complete blood count, and lipid panel were all within normal limits.
I am fortunate to continue having excellent care provided by my PCP, nephrologist, urologist, and psychiatric APRN. Together with these wonderful professionals, I have been able to maintain my physical and mental health.
Acknowledgment: I gratefully acknowledge the help and skills of Robin Scharak and Gary Blake for providing some of the editing on this article.
Bill Greenberg MS, RN, APRN
Delray Beach, Florida