Lithium effects on electrolyte excretion

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.

Intracellular ionized calcium and increasing doses of lithium chloride therapy in healthy Sprague-Dawley rats

The use of lithium salts in the prophylaxis and treatment of several psychiatric and neurologic disorders continues to be well accepted despite the apparent lack of understanding regarding its mode of action at the molecular level. This lack of delineation in the mechanism of action is supported by numerous conflicting publications. Despite the lack of understanding, a role for calcium in the manifestation of lithium's action is a constant singular consensus. Intracellular ionized calcium ([Ca2++]i) is involved in the proper functioning of cells because of its role in the second messenger pathway. It is therefore essential to evaluate the effect of lithium on intracellular calcium metabolism in a well-defined system. In this study, platelets loaded with Fura-2-Acetoxymethyl were used to evaluate the effect of intraperitoneally administered lithium chloride at 0, 2.5, 5.0, 7.5, and 10 mmol/kg body wt. on [Ca++]i. The results showed a slight relative increase in serum Ca++ that correlated well with the dose of LiCl administered to the rats. The baseline [Ca++]i were comparable in the study groups, but the response to thrombin stimulation was more pronounced at LiCl doses of 2.5, 5.0, and 7.5/kg body wt. compared with control and rats treated with 10 mmol LiCl/kg body wt. This finding suggests a dose-dependent response of [Ca++]i to LiCl treatment. The observation may therefore explain the variations that have been reported in [Ca++]i studies with respect to LiCl therapy using different doses.

The interaction of lithium and time-of-day on calcium, magnesium, parathyroid hormone, and calcitonin in rats

Effects of lithium on the concentrations and temporal patterns of serum and cerebellar calcium and magnesium, parathyroid hormone, and calcitonin were studied in 186 rats sacrificed around 24 hours of clock time. Serum calcium, serum and cerebellar magnesium, and parathyroid hormone were increased and calcitonin decreased in lithium-fed animals. Lithium-fed rats also showed different temporal patterns in serum calcium, parathyroid hormone, cerebellar magnesium, and calcitonin. Data support the hypothesis that lithium competes for calcium receptor sites, causing a compensatory increase in parathyroid hormone and decrease in calcitonin until a new, higher set-point for calcium is established. Lithium strongly affected biological rhythms, an effect which may account in part for the diverse literature on lithium's influence on calcium and magnesium regulation.

Relative effects of hyperbaric oxygen on cations and catecholamine metabolism in rats: protection by lithium against seizures

Analysis of lithium (Li+) in the brain and blood after intraperitoneal injection (i.p.) shows that initially its concentration is high in blood and negligible in the brain. Subsequently its concentration increases in the brain and disappears from the blood. Lithium itself affects neurological actions but the mechanisms remain obscure. It also modifies the toxic action of oxygen at high pressure (OHP), which causes convulsions, either suppressing or exacerbating it. These clearly separate effects correspond with the presence of Li+ in the blood (suppression) or in the brain (exacerbating). Determination of the effect of Li+ and OHP upon cations, catecholamines, ammonia, tyrosine hydroxylase, and monamine oxidase on brain and blood tissue showed that there was very little correspondence between changes in the cations either with Li+ or the toxic effects of OHP. On the other hand, OHP developed a sustained blood and brain hyperammonemia in rats which could be negatively modified by Li+ in the blood. The latter effect also corresponded with a prolongation of convulsive latency. Changes in brain catecholamines, tyrosine hydroxylase, monoamine oxidase and tyrosine were effected by Li+ and potentiated by OHP. These data suggest that Li+ and OHP mediate their effects relatively more through developing hyperammoneic states in both blood and brain than by altering cation concentrations in these tissues.

Platelet and erythrocyte-membrane adenosine triphosphatase activity in depressive and manic-depressive illness

An investigation of Mg2+ and (Na+ + K+)-dependent adenosine triphosphatase (ATPase) activities in the platelet and erythrocyte membrane of 44 depressive and 44 manic-depressive patients was carried out before and during (for 3 weeks to less than 1 year) drug treatment. When compared with normal controls (n = 43), the patients showed significantly elevated enzyme activities during both the drug-free and drug treatment periods. No remarkable changes in enzyme activities were observed between the drug-free and drug treatment (even long-term drug treatment) periods. Results suggest an alteration of cell-membrane activity, which may reflect changes in (1) ATP level, (2) cationic balance, (3) membrane phospholipid, or some combination thereof.

Lithium distribution ratios in psychiatrically normal subjects

Lithium was administered as the carbonate to 6 psychiatrically normal subjects for 11 days. The distribution of lithium between the erythrocytes and plasma, and the effect of exogenous lithium on intracellular and extracellular electrolytes was studied. The ratio of the concentrations of lithium in the erythrocytes and plasma was apparently lower in the normal group than in the patients diagnosed to have affective disorders.

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.

Calcium metabolism in lithium-treated patients. Relation to uni-bipolar dichotomy

The bone mineral content (BMC) together with biochemical indices of calcium metabolism were measured in 83 manic-depressive patients on long-term lithium therapy. The patients were diagnosed and divided into a unipolar and a bipolar group according to strict symptomatic course criteria. The patients with bipolar course had a significantly decreased BMC (88% of normal, P is less than 0.001), while the unipolar patients had normal BMC. Both groups had biochemical changes consistent with primary hyperparathyroidism.

Time course of lithium-induced alterations in renal and endocrine function in normal and Brattleboro rats with hypothalamic diabetes insipidus

1. A lithium chloride (1.1 g/kg) supplemented diet was given to Long Evans (LE) and Brattleboro (DI) rats to investigate its actions in the presence (LE) and absence (DI) of vasopressin. 2. During the first 24 h, Li-supplemented LE rats displayed an initial water deficit (drinking less than renal output), increased plasma antidiuretic (ADH) titres and slightly increased plasma renin activities (PRA) and plasma osmolarities. Such changes were qualitatively similar to those seen in rats fed a normal diet, but deprived of water for 24 hours. After 12 days, the Li-supplemented rats had elevated plasma ADH titres, but reduced pituitary oxytocic and antidiuretic activities. 3. The urinary losses of Na, K and Cl exceeded dietary intakes in LE rats on the introduction of the Li-supplement, and the urinary osmolarity fell by 50%. Electrolyte balances were gradually re-established, although drinking and urine production increased in parallel to reach twice the control values by day 12 of the supplement. 4. Aldosterone and corticosterone secretory rates and their peripheral plasma concentrations were unchanged both after 24 h and 28 days of the Li-supplement. 5. Li elicited no water deficit or saluresis in DI rats, and although the polyuria and polydipsia were exacerbated, urinary osmolarity did not change over the 12 day observation period. 6. Li increased Ca excretion in both rat types; after 12 days the PRA of DI but not LE animals were increased. 7. It is concluded that the overall renal actions of Li are tempered by vasopressin rather than adrenocorticosteroids.

The effects of administering lithium carbonate on the balance of Na, K and water in manic-depressive patients

Eleven patients in remission from manic-depressive illness were studied by means of metabolic balances before and after the administration of lithium carbonate. Lithium caused a sharp diuresis of isotonic saline and a smaller excretion of potassium over the course of two days. During the subsequent two days there occurred a compensatory retention of Na, K and water. These short-term changes were not associated with any significant alteration in the patients' mood. There was no significant and systematic retention of Na, K or water over the 14 days of Li administration. The recovery of Li was measured simultaneously. During the first week only a proportion of the administered Li was recovered in the urine and faeces, suggesting that a gradual distribution of Li throughout its body space was occurring. After the first week, nearly all the administered Li was recovered, indicating an equilibrium with an even distribution of the ion throughout its body space. This equilibrium was more complete at this early stage in those patients who had been given a smaller dose of lithium carbonate.

Lithium effects on diurnal rhythm of calcium, magnesium, and phosphate metabolism in manic-melancholic disorder

The diurnal rhythm of plasma phosphate, calcium, and magnesium was studied in 34 lithium treated patients, in 42 other psychiatric patients, and in 47 healthy persons. Seventeen blood samples were drawn from each person during the 24-hour period. Lithium was given at 10 p.m. and in the next few hours plasma phosphate decreased compared with the two control groups. In the same period plasma calcium showed a temporary increase, whereas plasma magnesium was increased during the whole 24-hour period. The lithium treated patients had a reduced urinary calcium excretion during the night, and an increased urinary magnesium excretion during the day, whereas no changes were found in urinary phosphate excretion.

Relation between erythrocyte and plasma lithium concentrations as an index in psychiatric disease

In longitudinal and transverse studies, lithium was measured in plasma, serum and red blood cells (erythrocyte) of healthy male and female subjects as well as in patients of both sexes suffering from manic-depressive disease or schizophrenia. The results confirm that lithium in erythrocytes is lower than in plasma in all groups. The lithium concentration gradient between plasma and erythrocytes is not caused by a slow rate of diffusion through the erythrocyte membrane. The new result of the present study is the importance of sex, disease and age on the erythrocyte/plasma lithium ratio, which is significantly higher in female subjects with manic-depressive disease. This difference persists even during long-term lithium therapy. Older female schizophrenics also have a higher ratio of erythrocyte to plasma lithium than males of the same age. The findings emphasize the importance of endocrine investigation in mental disease and support the view that plasma lithium in humans does not always reflect the intracellular levels. The erythrocyte plasma ratio may also be of value in revealing diagnostic subgroups within the classical psychiatric framework.

Plasma renin activity in depressed patients treated with increasing doses of lithium carbonate

Plasma renin activity (PRA) was measured in the supine position and after active upright stance in patients with endogenous depression and in a group of healthy volunteers serving as controls. In the depressed patients, PRA was further investigated in the same conditions during treatment with increasing doses of lithium carbonate. Basal PRA values were lower in depressed patients than in normal controls, particularly in the upright stance, and tended to rise gradually during lithium therapy. These findings suggest that lithium may work as a stimulant of the renin-angiotensin system, and possibly as an antidepressant, by way of producing functional activation of the norepinephrine system independent of its action on the water and electrolyte balance.

Facilitation of noradrenaline uptake by lithium

It has been suggested that lithium exerts its antimanic effect by facilitation of noradrenaline uptake into adrenergic neurones. Evidence in support of this hypothesis has been obtained from pharmacological experiments in which the effects of lithium were observed on isolated tissue preparations and in whole animals. The effectiveness of lithium in facilitating the uptake of noradrenaline was greater under conditions of reduced noradrenaline uptake, as in the presence of cocaine, than under control conditions.

Lithium carbonate

The pertinent literature on lithium has been reviewed. It appears that in recent years there is renewed interest in the drug, its general and specific usage, its toxic effects and its research. It seems to have been generally accepted as specifically effective in the treatment of acute manic psychosis, and also it is believed to be useful as a prophylactic agent in selected cases of recurrent affective disorders.

Clinical experience with lithium carbonate

Lithium carbonate is described in this paper as a mood normalizing drug, and recent literature is reviewed and summarized.

Thirty-one patients were treated with lithium in doses of 600–1200 mg daily in order to attain a serum concentration of 0.5 to 1.5 meq./litre.

This drug quickly arrested ongoing manic attacks in eleven patients and, when used prophylactically, has averted expected manic attacks in all 19 cases.

Lithium, used in this way, also averted expected depressive reactions in eleven patients and modified such attacks in the remaining eight patients. Where it did not prevent illness it appeared to facilitate the action of added antidepressive drugs, while not being a potent antidepressive drug when used alone.

Lithium also showed promising results in the treatment of six patients with recurrent depressions and for five patients diagnosed as having schizoaffective reactions.

Careful studies are required to establish whether toxic effects on various organs will emerge after long usage, but lithium carbonate must be regarded as a remarkable addition to the existing list of psychiatric drugs. A full exploration of its clinical application is warranted.