Renal function in lithium and non-lithium treated patients with affective disorders

Prevalence of impaired kidney function in patients with long-term lithium treatment: A systematic review and meta-analysis

OBJECTIVES

Although lithium renal effects have been extensively investigated, prevalence rates of chronic kidney disease (CKD) in lithium-treated patients vary. Our aim was to provide prevalence estimates and related moderators.

METHODS

We performed a systematic review in PubMed/Embase until November 01, 2021, conducting a random effects meta-analysis of studies evaluating CKD prevalence rates in lithium-treated patients calculating overall prevalence ±95% confidence intervals (CIs). Meta-regression analyses included sex, age, body mass index, smoking, hypertension, diabetes, cardiovascular disease, lithium-treatment dose, duration, and blood levels. Subgroup analyses included sample size, diagnoses, and study design. Pooled odds ratios (OR) were estimated for studies including patients receiving nonlithium treatment. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Five, nine, and six trials were rated as high, fair, and low quality, respectively. In 20 studies (n = 25,907 patients), we estimated an overall prevalence of 25.5% (95% CI = 19.8-32.2) of impaired kidney function; despite lack of differences (p = 0.18), prevalence rates were higher in elderly samples than mixed samples of elderly and nonelderly (35.6%, 95% CI = 21.4-52.9, k = 2, n = 3,161 vs. 25.1%, 95% CI = 19.1-31.3, k = 18, n = 22,746). Prevalence rates were associated with longer lithium treatment duration (p = 0.04). Cross-sectional studies provided lower rates than retrospective studies (14.5%, 95% CI = 13.5-15.5, k = 6, n = 4,758 vs. 29.5%, 95% CI = 22.1-38.0, k = 12, n = 17,988, p < 0.001). Compared with 722,529 patients receiving nonlithium treatment, the OR of impaired kidney function in 14,187 lithium-treated patients was 2.09 (95% CI = 1.24-3.51, k = 8, p = 0.005).

CONCLUSIONS

One-fourth of patients receiving long-term lithium may develop impaired kidney function, although research suffers from substantial heterogeneity between studies. This risk may be twofold higher compared with nonlithium treatment and may increase for a longer lithium treatment duration.

Aquaporin-2 as a biomarker of distal renal tubular function using lithium as an experimental model

Aquaporin-2 protein levels can be detected in the urine of normal of subjects if measured after fluid deprivation. By contrast, in patients with nephrogenic diabetes insipidus caused by mutations in the aquaporin-2 gene, urine aquaporin-2 protein excretion cannot be detected. We propose that properly standardized measurements of urinary aquaporin-2 protein may provide a useful biomarker of distal tubular function in a variety of acquired conditions that impair concentrating ability including some nephrotoxic agents.

Lithium and the kidney: an updated review

Despite the availability of alternative agents, lithium continues to be the standard against which all mood stabilisers, prescribed for acute and maintenance treatment of bipolar (and, to a lesser extent, unipolar) mood disorders, are compared. As a medication often used on a maintenance basis for a lifelong disorder, the potential for lithium to cause long term organ toxicity has generated appropriate concern. Foremost among these concerns are its renal effects. Lithium adversely affects renal tubular function, causing polyuria secondary to a deficit in urine concentrating ability. This effect is probably progressive for the first decade of lithium therapy, i.e. it correlates with duration of lithium therapy. Although this effect of lithium is probably functional and reversible early in treatment, it may become structural and irreversible over time. In contrast, the effect of lithium on glomerular function is not progressive. Conclusions in this area are hampered by the evidence that patients with psychiatric disorders who are not receiving lithium also show defects in certain aspects of renal function. Despite the generally sanguine data on glomerular function, a very small group of patients may develop renal insufficiency due to lithium (possibly in conjunction with other somatic factors) in the form of interstitial nephritis. However, for the vast majority of patients, the renal effects of lithium are benign. Current strategies for minimising the renal effects of lithium include: (i) assiduously avoiding episodes of renal toxicity; (ii) monitoring serum lithium concentrations in order to achieve optimal efficacy at the lowest possible concentration; (iii) monitoring serum creatinine levels on a yearly basis, getting further medical evaluation when the serum creatinine level consistently rises above 140 mmol/L (1.6 mg/dl); and (iv) possibly administering lithium once a day.

Renal side-effects of long-term lithium treatment

The beta 2-Mg (beta 2-microglobulin) and GAG (glycosaminogyclan) excretions in 107 patients with bipolar disorder who had been on lithium treatment for 1-15 years were compared with 29 matched psychiatric control patients. 24-h urine volume, urine beta 2-Mg, GAG values were significantly higher, and maximal urinary osmolality was significantly lower in patients on lithium than in controls. No relationship was found between creatinine clearances and duration of illness, duration of lithium treatment and daily lithium dosages. Duration of lithium treatment was not related to the concentrating capacity. The beta 2-Mg excretion rates were significantly higher in patients with manifest polyuria and with severe concentration defect.

Are the renal effects of lithium modified by frequency of administration?

It has been claimed that the unwanted effects and toxicity of lithium can be minimized by changes in the dosing schedules. Twenty consecutive psychiatrically stable patients were investigated in a cross-over study to determine whether renal function and other biochemical tests change significantly with changes from once to twice or multiple doses per day or vice versa. There were no significant differences between the 3 study conditions on the mood rating scales or a side effect scale (UKU). Urine volume, test of renal function and other biochemical and hematological indices were similar in all study conditions. We thus conclude that dosing strategy does not consistently affect renal function in lithium-treated patients.

Association of levels of N-acetyl-beta-glucosaminidase with specific psychiatric symptoms in bipolar patients

The levels of N-acetyl-beta-glucosaminidase (NAG) in urine from 35 patients with bipolar affective disorder were compared with scores for the 90 items (symptoms) of the Symptom Checklist (SCL-90). There were significant negative correlations between NAG levels and 23 of the SCL-90 variables (symptoms). These symptoms could be grouped into the following categories: anxiety, unusual or psychotic thinking, suicidal thinking, dysphoria, irritability, nausea, headaches, memory problems, and loss of interest. Serotonin abnormalities may play a role in the production of many of these symptoms. The hypothesis that NAG could be a marker for a serotonin activity is discussed.

Effect of lithium dosing schedule on urinary output

Lithium has been reported to induce polyuria in up to 35% of patients receiving it. It has been suggested that polyuria may be reduced by using single rather than multiple daily dosing. However, this information is based on non-randomized studies, which used higher serum lithium levels than are currently used. In fact, the incidence of polyuria may be lower at currently used lithium levels, and the benefits of a single daily dose regimen on urine volume at these levels have not been assessed. We conducted a prospective randomized study to test the hypothesis that switching patients from multiple daily dose lithium to single daily dose lithium would significantly lower urine volume. Twenty-four patients previously stabilized on multiple daily dosing were randomly allocated to either single or multiple daily dose lithium. Twenty-four-hour urine volume, serum creatinine, creatinine clearance and serum lithium were measured at study entry and completion. Switching to single daily dose lithium did not significantly reduce the 24-h urine volume.

Lithium side effects in the medically ill

OBJECTIVE

This review will include the general pharmacology of lithium and discuss its effects on various organ systems, with emphasis on the medically ill patient as well as the geriatric patient with multiple medical problems.

METHODS

A full literature review on the side effects of lithium was performed. Attention is focused on the medically ill and possible drug interactions.

RESULTS

This review points to the numerous problems which can result in toxicity in the medically ill or the geriatric patient.

CONCLUSION

Serious side effects can be avoided with proper drug monitoring and knowledge of potential drug interactions.

Practical aspects of long-term treatment with lithium

There is no increase in the overall mortality of patients undergoing long-term lithium treatment compared with those receiving short-term treatment. Lithium causes a reduction in the incidence of suicide in patients suffering from manic depressive illness. Long-term treatment with lithium is more effective than treatment with imipramine or amitriptyline. Drug interactions may cause problems during long-term therapy with lithium. A reduction in plasma levels of lithium should be considered in stable patients on long-term prophylaxis. Discontinuation of therapy often results in a relapse. The toxicity of lithium is related to its effects on calcium transport.

Kidney functioning during lithium treatment: a prospective study of patients treated with lithium for up to ten years

A cohort of 53 patients with affective disorders who originally carried through renal functional tests before start of prophylactic lithium treatment were followed up prospectively after an average period of 8.5 years (range 7-10 years). Ten patients who had continued lithium treatment were re-examined. In this subgroup, the glomerular function was unaffected by the treatment, whereas the average urine volume increased during lithium treatment (NS). Polyuria and low renal concentrating abilities were also found before start of treatment and these findings underline the importance of access to renal baseline information prior to lithium treatment.

Lithium: long-term effects on the kidney. A prospective follow-up study ten years after kidney biopsy

Forty-six patients with recurrent affective disorders, who began prophylactic treatment with lithium an average of 20 years previously, were followed up prospectively after a ten-year observation period to assess renal function. Nineteen patients had maintained lithium therapy, and eight patients had died. Tubular function was almost unchanged and patients who had continued lithium had not shown increasing urine volumes, but patients who had received lithium in a single daily dosage at night had a significantly lower urinary output than those on a multiple-dosage schedule. The GFR decreased significantly, but the decline was essentially dependent on increasing age, except in two patients who had developed renal insufficiency. Renal function during chronic lithium treatment is related to age, lithium intoxication episodes, pre-existing renal disease, and treatment schedule rather than to duration of prophylactic lithium therapy.

Elevated levels of N-acetyl-beta-glucosaminidase in affective disorders and chemical dependence

Levels of N-acetyl-beta-glucosaminidase (NAG) were examined in 575 patients with various psychiatric diagnoses and 38 non-ill controls. Ten percent of affectively disordered patients and 19% of chemically dependent patients had abnormal NAG levels, whereas none of the 38 controls did (P less than 0.05 and P less than 0.003 respectively). Other psychiatric diagnostic groups were not associated with abnormal levels of this enzyme.

Long-term effects of lithium on the kidney: functional-morphological correlations

Correlations between quantitative kidney biopsy findings and clinical renal function in 46 unselected patients treated with lithium for an average of eight years were studied. A significant relationship between maximum renal concentrating capacity and degree of tubular atrophy was found. GFR correlated significantly with sclerotic glomeruli as well as atrophic tubules in patients on a multiple dosage schedule, whereas no relationship was seen in patients receiving lithium in a single daily dose. Thus, renal dysfunction may have a structural basis in a subgroup of lithium-treated patients on a multiple dosage schedule.

Lithium therapy: from clinical trials to practical management

Controlled trials have shown that lithium significantly reduces the morbidity of recurrent affective disorders. We describe here the ongoing affective morbidity in unipolar, bipolar and schizoaffective illness treated primarily by low dosage, once daily lithium, supplemented as necessary by antidepressant or neuroleptic medication. Seventy-eight percent of unipolar patients and 73% of bipolar and schizoaffective patients had no or only slight morbidity during the study year. The treatment was equally effective for both older (age greater than 70 years) and younger patients. Unipolar patients rated as endogenous on the Newcastle Scale had significantly lower morbidity than the nonendogenous patients. Subjective side effects were minimal. These patients, whose untreated morbidity is known to be high, derive considerable benefit from regular supervision in an affective disorder clinic.

Elevation of the renal enzyme N-acetyl-beta-glucosaminidase in affectively disordered patients

A minority of patients with affective disorders experience mild elevations of the renal enzyme N-acetyl-beta-glucosaminidase (NAG). Some affectively disordered patients also have reduced concentrating ability and reduced creatinine clearance. Thirty-one affectively disordered patients were compared to 17 healthy controls, to evaluate whether these various renal abnormalities are associated with one another and to further examine the proportion of affectively disordered patients experiencing NAG elevations. Twenty-nine percent of patients had an elevated NAG, whereas none of the controls did (P less than .005). There was a trend for an association between elevated NAGs and reduced creatinine clearance (P less than .08), but no association was found between concentrating ability and either elevated NAG or reduced creatinine clearance.

Prevalence, pathogenesis, and treatment of renal dysfunction associated with chronic lithium therapy

From the analysis of several studies published from 1979 to 1986 comprising 1,172 patients, we estimated that glomerular filtration rate (GFR) was normal in 85% of unselected patients on chronic lithium therapy. The remaining 15% of patients displayed only mild reduction in GFR, clustering at approximately 60 mL/min. Thus, the data available to date do not support earlier concerns that long-term lithium therapy could eventuate into renal insufficiency. The most prevalent renal effect of lithium is impairment of concentrating ability, which we estimated to be present in at least 54% of 1,105 unselected patients on chronic lithium therapy. This defect translated into overt polyuria in only 19% of unselected cases. A renal lesion confined to the collecting tubule has been described in humans who have taken lithium for short periods of time. This lesion may represent the collecting tubule's response to the intracellular accumulation of lithium, which interferes with cAMP formation and results in an early and probably reversible inhibition of antidiuretic hormone (ADH)-mediated water transport. However, long-term lithium therapy may induce a progressive and partly irreversible defect in concentrating ability. The potential risk for dehydration associated with lithium-induced polyuria, as well as the discomfort inherent to this side effect, deserves evaluation and consideration for therapeutic intervention. Amiloride has additional advantages over conventional treatment of nephrogenic diabetes insipidus using thiazide diuretics. The action of amiloride on ADH-mediated water transport seems specific in as much as it is capable of preventing the uptake of lithium in high resistance epithelia and thereby prevents the inhibitory effect of intracellular lithium on water transport. Unlike thiazides, amiloride has a weak natriuretic effect and is less likely to increase plasma lithium levels by causing volume contraction. In addition, amiloride, by conserving potassium, obviates the need for potassium supplementation that is usually required to prevent hypokalemia when thiazides are used to treat lithium-induced polyuria. Since amiloride may prevent chronic intracellular lithium accumulation in the collecting tubule, future studies should elucidate whether amiloride also has a role in preventing lithium-induced chronic tubulo-interstitial damage.

Lithium: long-term effects on the kidney. IV. Renal lithium clearance

Renal lithium clearance was investigated in 44 patients treated with lithium for an average of 8 years as part of a functional-morphological follow-up study including a kidney biopsy. The average renal lithium clearance was 0.36 ml/s (= 21.6 ml/min). A significant correlation with age, sex and glomerular filtration rate was seen, whereas no significant relationship with urine volume, lithium treatment regimen and histopathological biopsy variables was found. The results were compared with the same renal functional tests obtained from a control group consisting of 26 patients with affective disorders never treated with lithium. The control group had a lower urine output, but no significant difference in lithium clearance was observed. In conclusion, renal lithium clearance is a specific investigation, which may provide valuable baseline information on glomerulo-tubular function in patients before and during prophylactic lithium treatment.

Lithium and impairment of renal concentrating ability

In 19 patients on lithium maintenance therapy, impairment of renal concentrating ability was found to correlate with daily lithium dose. The correlation between dose and impaired renal concentrating ability was strongest for patients on regular lithium preparations and not significant for patients on a slow release preparation. In 2 patients with severe polyuria, renal concentrating ability increased markedly with thiazide treatment. No relationship between lithium dosing parameters and other side effects was found. These results emphasize the importance of dose and type of preparation of lithium in the production of renal side effects.

Side-effects of lithium at lower therapeutic levels: the significance of thirst

The prevalence of thirst, subjective polyuria and related side-effects was investigated in 87 patients attending a lithium clinic and in a group of 52 controls. Thirst was surprisingly common, occurring in 67% of patients, in spite of the fact that they had been maintained on relatively low levels of lithium, and was due principally to the lithium rather than to other psychotropic drugs. Urine flow and impaired renal water absorption correlated with the serum lithium level and the length of treatment in the patients, despite the fact that few were clinically polyuric. The pattern of the results confirms previous suggestions that lithium may stimulate the thirst mechanism directly as well as via an increased renal resistance to vasopressin. The possible implications in terms of clinical response are discussed.

Neuroleptics, lithium and renal function

Renal function test results in 26 patients on neuroleptic treatment, who had never received lithium or antidepressants, were compared with those in a matched group, treated with lithium; also, their tubular response to DDAVP was compared with that of 25 control subjects. Measurements of serum creatinine, creatinine clearance, and urinary albumin excretion showed no abnormality attributable to either neuroleptics or lithium. The maximum urine concentrating ability after DDAVP was significantly lower in the neuroleptic group than in controls, but significantly higher than in the lithium-treated patients. There was a significant correlation between excretion of urinary beta 2-microglobulin and duration of neuroleptic treatment, but mean excretion rates were the same in both treatment groups. The results suggest that neuroleptics as well as lithium impair urine concentrating ability.

Renal function in 153 manic-depressive patients treated with lithium for more than five years

Renal function was examined in 153 manic-depressive patients treated with lithium for more than 5 years, mean 10 years. No significant change was detectable in plasma creatinine. Glomerular filtration rate (GFR) decreased slightly, but significantly, and not until after 17 years of treatment did the regression line reach the lower confidence limit in the reference material. GFR was generally only moderately decreased. Renal concentrating capacity was significantly reduced during the whole investigation period and did not change with time. GFR was independent of the dosage pattern. The diuresis did not differ markedly in patients given one or three daily doses. In a two-dose group predominantly treated with slow-release tablets, the diuresis was somewhat higher in 75% of the patients but much higher for the rest of the group. Since the prophylactic effect of lithium was the same in the one-dose group (mean dosage 21 mmol/day) as in the two-dose and three-dose groups (mean dosage 27-28 mmol/day), our data indicate that generally employed lithium doses may be reduced somewhat without loss of prophylactic efficacy.

Lithium adverse reactions in psychiatric patients

A brief review of the literature on the adverse reaction of lithium therapy in man is presented. This was aimed at both toxic and side effects of lithium on various organ systems of the body. Inconclusive, insufficient or conflicting data were found in several areas of possible lithium-induced toxicity, notably in lithium-associated nephrotoxicity. Results of prospective studies are needed to clarify this issue. Adverse reactions derived from continued administration of lithium salts with neuroleptic medications or with electroconvulsive therapy were also reviewed. Lithium-induced side effects on the endocrine and gastrointestinal systems were also summarized along with both dermatologic and ophthalmologic effects. The teratogenicity of lithium during pregnancy and its cardiovascular abnormalities were discussed. The target organs of lithium poisoning and their management were also presented.

Kidney function in lithium-treated patients. A literature survey

Twenty-three studies of the effect of lithium treatment on tubular and glomerular function are reviewed. They include about 1,450 patients from a total population of more than 2,000. One hundred and thirty-two patients were kidney biopsied. In addition, two specific questions are reviewed: 1) Does combined treatment lithium/neuroleptics affect the kidneys adversely? 2) Do different lithium preparations or treatment schedules affect the kidneys differently?

CONCLUSIONS

In a small proportion of patients long-term lithium treatment causes morphological changes of a tubulointerstitial type and partly irreversible reduction of tubular function. Glomerular function is reduced secondary to tubular atrophy. Combined treatment with neuroleptics does not increase the risk of kidney damage. Types of lithium preparation do not affect kidneys differently. Multiple-dose schedules may be associated with a higher urinary output than one-dose schedule. Reduced renal function may in the future become a problem in an increasing number of patients.

The effect of lithium on renal haemodynamic function

Renal concentrating capacity following 18 hours of fluid deprivation was measured in 75 patients receiving prophylactic lithium therapy, and in 30 affectively ill subjects receiving other drugs. The lithium-treated patients had significantly lower urine osmolality and higher serum osmolality than the control subjects. Older subjects, patients maintained at higher serum lithium levels and those with a history of previous neurotoxicity showed the most impairment. Ten patients with urine osmolalities of less than 700 mOsm/1 following this test were investigated further. Inulin and para-amino hippurate (PAH) clearance rates were determined and the effect of a subpressor challenge of dopamine on these measures was observed. Half of the patients showed some reduction in inulin and PAH clearance, which was greatest in those patients who had been taking lithium for over 10 years. However, all of the patients tested showed the expected increase in renal blood flow and sodium and water excretion in response to dopamine. Six additional patients had clearance estimations made before starting lithium treatment which were repeated after a period of 3-6 months on the drug. No consistent changes in haemodynamics were observed. Lithium clearly reduces renal concentrating capacity, but other measures of renal tubular function were well preserved in patients receiving long-term therapy. Glomerular function may be slightly reduced in patients taking lithium for long periods. The results show that prophylactic lithium treatment does not affect renal cortical function adversely in the majority of patients, but impaired renal concentrating ability is a common accompaniment.

Urinary beta-hexosaminidase excretion in patients treated with lithium, thymoleptic and/or neuroleptic drugs

In order to evaluate the nephrotoxic effect of serum lithium within the therapeutical range, the urinary excretion of beta-hexosaminidase was studied in 44 well-managed long-term lithium treated patients and in 27 healthy controls. In addition, six patients on thylmoleptic and 16 patients on neuroleptic drugs were studied. The enzyme excretion was slightly increased in the lithium treated patients, but not in the patients only treated with thymoleptic or neuroleptic drugs. The findings are consistent with the suggestion that long-term lithium treatment causes a slowly progressive nephropathy. To follow the urinary beta-hexosaminidase excretion might be a measure to identify patients at higher risk. In two cases of lithium intoxication the enzyme excretion was considerably increased.

Lithium nephrotoxicity

Lithium-induced nephrotoxicity was first predicted in laboratory animals more than 30 years ago. Evidence in humans, however, did not begin to accumulate until the 1970s. By 1977, anecdotal information was available to suggest that lithium intoxication was not necessarily a prerequisite for the development of nephrotoxicity and that renal damage also could occur as a result of chronic lithium therapy. Since then, several factors have been identified that could influence the risk of nephrotoxicity during treatment with lithium. These include number of daily doses, type of lithium formulation, and the incidence of renal disease in patients with manic-depressive illness.