Letter: Lithium, hypercalcaemia, and hyperparathyroidism

Drug-Related Hypercalcemia

This review focuses on the commonly prescribed medicaments that can be responsible for hypercalcemia, considering the prevalence, the predominant pathophysiological mechanisms, and the optimal medical management of each drug-induced hypercalcemia. Vitamin D supplements and 1α-hydroxylated vitamin D analogues increase intestinal calcium absorption, renal calcium reabsorption as well as bone resorption. In patients with hypoparathyroidism receiving recombinant human PTH, transient hypercalcemia can occur because of overtreatment, usually during acute illness. Thiazide-induced hypercalcemia is mainly explained by enhanced renal proximal calcium reabsorption, changing preexistent asymptomatic normocalcemic or intermittently hypercalcemic hyperparathyroidism into the classic hypercalcemic hyperparathyroidism. Lithium causes hypercalcemia mainly by drug-induced hyperparathyroidism.

The prevalence of lithium-associated hyperparathyroidism in a large Swedish population attending psychiatric outpatient units

OBJECTIVE

This retrospective study determined the prevalence of lithium-associated hyperparathyroidism (LHPT) in 2 geographically defined, equivalent populations in Sweden, with no other selection bias.

METHODS

The medical journals of all patients receiving lithium treatment were examined specifically regarding their biochemistry: calcium, parathyroid hormone (PTH), creatinine, and vitamin D. The condition LHPT was defined biochemically. All patient data were noted, and the prevalence of the condition could thereby be calculated.

RESULTS

A total of 423 patients were included (251 women and 172 men; 3:2), treated over a mean of 13.5 years (range, 1-46 years), aged 19 to 92. 77 patients (18%) were identified with LHTP whose median serum calcium was 2.55 mmol/L and PTH was 99 ng/L. A further 21% showed tendencies toward hypercalcemia. Forty-three percent had vitamin D insufficiency. Five patients (approximately 1%) had undergone parathyroidectomy.

CONCLUSION

The prevalence of LHPT is high and often goes undetected. Vitamin D insufficiency is common as is polypharmacy. Surgery, for unclear reasons, has not been performed extensively, possibly because of limited knowledge of the underlying pathophysiology or surgery's significance. We present standard recommendations on patient management and suggest continual, specific follow-up including the monitoring of calcium, PTH, and vitamin D at least annually. Surgery should be considered with intention to improve psychiatric well-being and provide multiorgan protection.

Hypercalcemia in patients with bipolar disorder treated with lithium: a cross-sectional study

BACKGROUND

Lithium-induced hyperparathyroidism (LIH) is a relative underrecognized complication of long-term lithium treatment. Hypercalcemia may be the first, but often overlooked, sign of LIH. Symptoms of LIH can be similar to the underlying psychiatric illness, which may cause a significant doctor's delay in diagnosing LIH. The aim of this study was to determine the prevalence of hypercalcemia in a cohort of psychiatric patients.

METHODS

In this cross-sectional study, we collected data from 314 patients treated with lithium in an outpatient clinic for bipolar disorder. Patients with bipolar disorder from the same clinics, who had never been treated with lithium and of whom serum calcium levels were available, were included as controls (n = 15). Patient characteristics and laboratory results were collected during the period of June 2010 till June 2011.

RESULTS

The mean serum calcium level was 2.49 (SD 0.11) mmol/l. The point prevalence of hypercalcemia (>2.60 mmol/l) was 15.6%. In a comparable group of psychiatric patients not using lithium, the mean serum calcium level was 2.37 mmol/l, and none of these patients had hypercalcemia (p = 0.001). The duration of lithium treatment was the only significant predictor for the development of hypercalcemia (p = 0.002).

DISCUSSION

The prevalence of hypercalcemia in lithium-treated patients was significantly higher than that in non-lithium treated controls and correlated to the cumulative time lithium was used in this cross-sectional study. We recommend that serum calcium levels should be routinely tested in patients using lithium for timely detection of LIH or hypercalcemia due to other causes.

Lithium-associated hypercalcemia and hyperparathyroidism in the elderly: what do we know?

BACKGROUND

Lithium has been reported to induce hypercalcemia and hyperparathyroidism, yet few studies have examined the impact on older patients. We therefore undertook this review and report our findings.

METHOD

We undertook a systematic review of articles on lithium-associated hypercalcemia and/or hyperparathyroidism that were identified via electronic English language database searches through PubMed.

RESULTS

Among reported cases and case series of lithium-associated hyperparathyroidism in which ages of specific subjects were provided, 40% of affected individuals were over age 60. Mean serum calcium levels are reported to be higher in lithium treated patients over age 60 compared with younger patients. While many patients who develop lithium-associated hypercalcemia and hyperparathyroidism are asymptomatic, symptomatic complications may be more of a concern in older patients, especially in those with co-morbid renal disease.

LIMITATIONS

To date, all cross-sectional studies of lithium-associated hypercalcemia and hyperparathyroidism are of mixed age group cohorts and more specific studies focused on older patients have yet to be performed.

CONCLUSIONS

Lithium-induced hypercalcemia and hyperparathyroidism are under-recognized potential complications of lithium therapy which may occur more frequently in older patients. Psychiatrists should be vigilant in screening for hypercalcemia and hyperparathyroidism in their older patients receiving lithium, both prior to starting treatment and at least annually thereafter.

Long-term results of surgery for lithium-associated hyperparathyroidism

BACKGROUND

Lithium therapy for affective bipolar disease is frequently associated with hyperparathyroidism (HPT), but the results of surgical treatment are virtually unknown. The aim of this retrospective review was to analyse the long-term outcome after surgery for lithium-induced HPT in a large series of patients.

METHODS

Seventy-one patients on chronic lithium therapy who underwent surgery in three university and three district hospitals in Sweden were followed for a median of 6.3 years. Histopathology, complications of surgery and normocalcaemia at 6 months after surgery and last follow-up were analysed.

RESULTS

The primary histopathological diagnoses were adenoma (45 per cent), double adenomas (3 per cent) and hyperplasia (52 per cent). No permanent paresis of the recurrent laryngeal nerve was recorded but 13 per cent of the patients suffered from permanent hypoparathyroidism. At follow-up, the rate of persistent and recurrent HPT was 42 per cent regardless of the histopathological diagnosis.

CONCLUSION

The results of conventional surgery for lithium-associated HPT are poor. The surgical approach should be adjusted for the multiglandular disease that is usually the cause of HPT in patients on chronic lithium therapy.

Appropriate surgical treatment of lithium-associated hyperparathyroidism

BACKGROUND

Lithium is frequently used in the treatment of bipolar disease. Although lithium-associated hyperparathyroidism (LAH) is well documented, reports concerning its pathologic findings are sparse. Because of a high-reported incidence of multiglandular disease, focused exploration for LAH is controversial.

METHODS

From 1995 to 2007, data from 1207 consecutive patients who underwent concise parathyroid exploration for sporadic primary hyperparathyroidism (PHP) directed by quick intraoperative parathyroid hormone monitoring (QPTH) were reviewed to identify patients with LAH. Anatomic findings were determined. All patients had >5 months of follow-up.

RESULTS

The incidence of LAH was 16/1207 (1.3%). The rate of multiglandular disease was not higher in LAH: present in 25% (4/16) patients with LAH and 12.3% (146/1191) patients without LAH (p = 0.13 Fisher two-tailed test). Among 16 patients with LAH, 12 (75%) had a single adenoma. The use of QPTH allowed unilateral exploration in 8 of 12 patients with single adenoma. Parathyroid exploration resulted in durable biochemical cure for all 16 patients with LAH.

CONCLUSION

Multiglandular disease seems to be no more frequent in patients with LAH than in patients with primary hyperparathyroidism (PHP) without LAH. Patients with LAH can be safely and effectively managed with selective unilateral exploration directed by intraoperative PTH monitoring.

Hypercalcémie grave secondaire à une hyperparathyroïdie induite par le lithium

Lithium treatment, which is still extensively used in bipolar affective disorders, may give rise to hypercalcaemia induced by hyperparathyroidism. We present a patient of 50-year-old treated with lithium for 19 years for bipolar illness and who developed an important hypercalcaemia. After symptomatic treatment of the hypercalcaemia and extrarenal dialysis the clinical evolution was favorable but measurements of serum calcium and parathormon showed that he had developed hyperparathyroidism. Neck exploration was performed and parathyroid adenomas, which had been detected by scintigraphy was removed. The lithium treatment expose to many side effects. Among other biologically and clinically important effects of lithium the possible induction of hyperparathyroidism was first suggested in 1973. Since, 1973, since about forty case reports have been described. Few cross-sectional studies show a relationship of lithium to hyperparathyroidism. Unusual metabolic features are associated with hyperparathyroidism and long-term lithium treatment: low urinary calcium excretion, normal urinary cyclic AMP excretion. The mechanism probably results from lithium linking with the calcium receptor on the parathyroid and then stimulating PTH secretion. The cessation of lithium therapy does not lead to normocalocaemia and a parathyroidectomy is usually indicated.

[Hyperparathyroidism induced by lithium. A new case]

INTRODUCTION

Lithium salts, used for the first time in 1949, had proved to be a highly effective preventive measure in bipolar illness. The first report of lithium-induced hyperparathyroidism was suggested by Garfinkel et al. in 1973. About 40 cases have been reported since, suggesting an enhancement of occurrence of hyperparathyroidism in patients cured by lithium carbonate. We report here a new case discovered by a systematic measurement of calcemia after a surgical intervention for a hip joint prosthesis.

EXEGESIS

Unusual metabolic features associated with this case of hyperparathyroidism include low urinary calcium excretion, normal cyclic AMP excretion and lack of calcic nephrolithiasis. The mechanism probably results from lithium linking with the calcium receptor on the parathyroid and then stimulating PTH secretion. In the same way it could enhance the tubular reabsorption of urinary calcium. Lithium withdrawal is often inefficient in clinical and laboratory test abnormalities and surgery is usually required.

CONCLUSION

It is very important to recognise this particular secondary effect of lithium therapy because clinical symptoms of hypercalcemia can simulate a worsening of the bipolar illness.

Pathology and outcome of surgical treatment for lithium-associated hyperparathyroidism

BACKGROUND

Hyperparathyroidism associated with long-term lithium therapy is well described. However, few studies have clearly defined the pathological findings or looked at the outcome of surgical treatment.

METHODS

The study was a retrospective review of 11 patients with bipolar affective disorder who had surgery for lithium-associated hyperparathyroidism.

RESULTS

Twelve patients were identified who had received lithium therapy, of whom 11 (nine women and two men, aged 46-84 (mean 65) years) had prolonged treatment from 2 to 30 (mean 15.3) years. At operation a single adenoma was identified in six patients, whereas multigland disease was seen in five patients. All patients resumed lithium treatment after operation. One patient had recurrent hyperparathyroidism at 3 years, while another had an increased serum level of parathyroid hormone in the presence of a normal serum calcium level after 1 year.

CONCLUSION

Hyperparathyroidism associated with lithium may be due to either parathyroid hyperplasia or adenoma. Observations in the present study supported a true cause and effect relationship. Routine bilateral neck exploration should be performed because of a relatively high frequency of multigland involvement. However, parathyroid resection should be limited to evident disease.

Lithium Therapy and Disorders of the Parathyroid Glands

OBJECTIVE

To review the effects of lithium (Li+) on the parathyroid glands.

METHODS

We describe the incidence and clinical features of Li(+)-associated hyperparathyroidism and summarize the current state of knowledge of the in vitro and in vivo effects of Li+ on the parathyroid cell.

RESULTS

Li+ treatment is known to increase the calcium set-point in the parathyroid glands for inhibition of parathyroid hormone secretion. Evidence suggests that this change in calcium set-point occurs as a result of Li+ interference with transmembrane signal transduction in the parathyroid cell. Li+ therapy may accentuate the set-point error in patients with primary hyperparathyroidism and unmask preexisting hyperplastic or adenomatous changes in the parathyroid glands. Li+ may also cause de novo hypercalcemia and hyperparathyroidism that are usually mild, clinically insignificant, and reversible with discontinuation of Li+ therapy. In some patients receiving long-term Li+ therapy, however, persistent hyperparathyroidism develops despite discontinuation of Li+ therapy, and it may be symptomatic and associated with serious organ system sequelae. Li(+)-associated hypercalcemia can be a challenging clinical dilemma in patients with bipolar affective disorder because of the lack of effective therapeutic alternatives, as well as the potential for Li(+)-induced hypercalcemia to exacerbate psychopathologic symptoms.

CONCLUSION

Because severe hypercalcemia may occur as a result of toxic Li+ levels, Li+ and calcium levels should be monitored in patients on long-term Li+ therapy.

Lithium-induced parathyroid dysfunction: a case report and review of the literature

OBJECTIVE

Twenty-six cases of lithium-induced hyperparathyroidism have been reported in the literature. This article describes an additional case that illustrates current management recommendations.

DESIGN

Case report. Clinical presentation and proposed mechanisms of the suspected drug-induced effect are discussed.

CONCLUSIONS

Serum calcium concentrations should be determined before and periodically during long-term lithium carbonate therapy. Discontinuation of therapy in patients who develop lithium-induced parathyroid dysfunction generally corrects calcium and parathyroid hormone concentrations. Surgery is indicated in patients with complications of hyperparathyroidism.

Lithium and immune function

Lithium has potent antiviral and immunostimulating properties which are probably consequences of its actions on prostaglandin synthesis. Although lithium has considerable potential in the prophylaxis of some viral illnesses and other manifestations of defective immune function, it is, paradoxically, capable of activating autoimmune mechanisms in predisposed patients.

Cholinergic mechanisms in affective disorders. Future directions for investigation

Advances in clinical and basic research methodology combined with clearly articulated concepts create new opportunities for researching the roles of cholinergic mechanisms in the pathophysiology of affective disorders. Areas for study include: roles of cholinergic mechanisms in mediating effects of stress and cholinergic mechanisms linking the pathophysiologies of affective and panic disorders, use of pharmacologic agents to produce cholinergic system supersensitivity in modeling biologic aspects of affective illness, use of multigenerational intrapedigree studies of cholinergic markers associated with affective disease, research into the neurobiology of lithium and ECT as they pertain to muscarinic cholinergic mechanisms, study of the interrelationship of sodium, calcium and lithium ion metabolism and their relationship to cholinergic-monoaminergic interaction, the development of brain imaging strategies and techniques, e.g., positron emission tomography (PET), to measure changes in cholinergic receptor density and affinity as a function of clinical state, identification and validation of a peripheral model of the central muscarinic receptor, study of the pharmacology of abusable substances and its relationship to mechanisms regulating mood, affect, psychomotor function and other variables related to the affective disorders, and development of in vitro and in vivo models useful in studying the physiology and biochemistry of the interaction of cholinergic and monoaminergic neurons. These models may allow us to bridge the traditional cholinergic and monoamine hypotheses of affective disorders.

Symptomatic reactive hypoglycemia during glucose tolerance test in lithium-treated patients

Glucose, insulin, glucagon, and cortisol responses during a five-hour oral glucose tolerance test (GTT) were evaluated in nine patients with bipolar affective disorders who were receiving lithium treatment and in seven control patients with bipolar affective disorders who were not receiving any treatment. Both the lithium-treated and the control patients were in stable mood at the time of GTT. During GTT mean nadir serum glucose of 48 +/- 2 mg/dL in the lithium-treated patients was significantly lower (P less than 0.001) than mean nadir serum glucose of 62 +/- 2 mg/dL observed in the control subjects. Seven of these nine lithium-treated patients, but none of the control patients, experienced hypoglycemic symptoms coinciding with low serum glucose concentration. In response to hypoglycemia, mean serum cortisol significantly rose (P less than 0.01) to 22 +/- 3 micrograms/dL in the lithium-treated patients, whereas mean serum cortisol levels gradually declined to 10 +/- 2 micrograms/dL in the control patients at 300 minutes. Despite symptomatic postglucose hypoglycemia, plasma glucagon levels in the lithium-treated patients were similar to those observed in the control patients. These findings suggest that chronic lithium treatment is associated with a symptomatic and biochemical hypoglycemia during GTT, which is characterized by a rise in serum cortisol but by lack of appropriate rise in plasma glucagon concentrations.

Alterations in human serum alkaline phosphatase and its bone isoenzyme by chronic administration of lithium

There are conflicting data on the effects of lithium on bone metabolism. Bone formation is known to be reflected by the activity of alkaline phosphatase of the bone tissue. We have found significant differences in mean serum alkaline phosphatase and its bone isoenzyme levels between a group receiving lithium and a control group. In this study increased bone isoenzyme of alkaline phosphatase activity above the normal range was found in 27 of 41 patients treated with lithium carbonate. In 19 of 41 patients treated with lithium the activity of bone isoenzyme was increased above the normal range even in the absence of increased activity of serum total alkaline phosphatase.

Differential laboratory diagnosis of hypercalcemia

It is proposed that this review will adopt the following format: establishment of hypercalcemia. This demands a discussion of the problem of normal ranges, the usage of either total calcium or ionized calcium in making this decision and where total calcium is used whether adjustment of this value for serum protein concentration should be used and if so, the formulae which have been cited to perform this. Having established hypercalcemia why is it necessary to differentiate this? This will involve reviewing those clinical situations in which differentiation of hypercalcemia has been attempted and will include an attempt to produce an up to date indication of conditions in which hypercalcemia has been described. When hypercalcemia has been established the laboratory tests which have been further used to discriminate will be divided into single tests such as N- or C- terminal parathormone, 1,25- dihydroxycholecalciferol, cyclic AMP; the combination tests which have been used including phosphate clearance, chloride vs. bicarbonate etc. proceeding to those groups which have used discriminant function to help in the decision making; dynamic testing will also be discussed particularly with reference to steroid suppression but will also include other known suppressants such as Mithramycin and Calcitonin. A final section will be included attempting to assess overall the present state of art in differentiating laboratory diagnosis of hypercalcemia and will also attempt to highlight those areas which appear to be most fruitful areas of progress in the future.

Lithium and symptomatic hyperparathyroidism

Hyperparathyroidism with or without adenoma has occasionally been reported in association with lithium treatment, and in symptomatic patients depression, psychosis and an exacerbation of existing psychopathology may occur. Three lithium-treated patients with hyperparathyroidism are reported, in whom discontinuation of lithium in one and removal of parathyroid adenomata in two led to both a reduction in plasma calcium levels and an improvement in their psychopathology.

Lithium-induced changes in the plasma and pituitary levels of luteinizing hormone, follicle stimulating hormone and prolactin in rats

Adult male Sprague-Dawley rats, maintained under a controlled photoperiod of LD 14:10 (white lights on at 06:00 h, CST), were injected with lithium chloride and changes in the levels of plasma and pituitary homogenates of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were examined to evaluate the effects of this anti-manic drug on reproductive function. Two groups of rats were injected with lithium chloride intraperitoneally, twice daily at 09:00 and 16:00 h, for 2 and 7 days at a dosage of 2.5 meq/Kg body weight. Plasma and pituitary levels of LH, FSH and PRL were measured by radioimmunoassay. Plasma levels of LH were significantly (P less than 0.05) increased after 2 days of lithium treatment. In contrast, a significant (P less than 0.005) reduction in plasma levels of LH was evident when lithium injections were continued for 7 days. The plasma levels of FSH remained unaffected by lithium treatment by either time period. Lithium administered for 2 days did not bring about any significant alteration in the plasma levels of PRL, although there was a significant (P less than 0.002) reduction in plasma PRL levels after 7 days treatment. The concentrations of pituitary LH, FSH and PRL remained unchanged after 2 and 7 days of lithium treatment.

Recommendations for monitoring lithium therapy

The literature concerning side effects of normal serum levels of lithium on various organ systems is reviewed. Suggestions for monitoring and managing these adverse effects are discussed. A table is presented that provides recommendations for evaluation prior to initiation and during follow-up of therapy.

Drug-induced electrolyte disorders

A wide variety of pharmacologic agents have been implicated in a number of electrolyte disorders. The present review focuses on abnormalities of sodium, potassium, calcium, magnesium, and phosphate. Several mechanisms are involved in the pathogenesis of these disorders. These involve stimulation and modulation of other hormones (e.g., antidiuretic hormone, renin-angiotensin system, parathyroid hormone), damage to renal tubules, and, in some cases, a combination of factors. Recognition of these abnormalities is important because their presence may be life threatening or may aggravate the side effects of the drug itself.

Mechanism of lithium-induced hypercalciuria in rats

Chronic administration of lithium salts is associated with hypercalciuria in the rat. To study the renal and extrarenal mechanisms of this phenomenon, we utilized balance and clearance techniques in rats pair-fed diets with or without Li2CO3 (0.5 meq/day per rat). Lithium induced hypercalcemia (mean +/- SE: 5.40 +/- 0.09 VS. 5.06 +/- 0.05 meq/liter) and hypercalciuria (Ca/creatinine = 0.28 +/- 0.04 vs. 0.13 +/- 0.03) only during feeding. When CaCO2 supplement to a calcium-deficient diet was abruptly withdrawn, hypercalciuria was abolished. However, polyuria and polydipsia persisted. No significant changes in serum phosphate, urine phosphate, sodium, pH, or citrate were observed. Chronic parathyroidectomy (PTX) also abolished this effect. During clearance studies, fasting excretion of calcium was similar between treated and control animals. Superimposed acute PTX resulted in comparable changes, hence arguing against primary changes in renal calcium reabsorption or changes in parathyroid hormone effects on the renal tubule. Thus, lithium produces absorptive hypercalciuria by a mechanism dependent on intact parathyroid glands and adequate diet calcium, but independent of urine sodium, phosphate, or pH. The active component of gut calcium transport may be involved, possibly via alterations of vitamin D metabolism.