Lithium discontinuation and subsequent effectiveness

Lithium-discontinuation-induced treatment refractoriness revisited

BACKGROUND

Lithium is effective in the long-term treatment of bipolar disorder. Concerns have been raised about non-responsiveness after discontinuation and resuming previously effective lithium prophylaxis. We reviewed the available literature on this so-called lithium-discontinuation-induced treatment refractoriness (LDITR).

RESULTS

We found 11 case reports and six cohort studies including 403 patients addressing LDITR, and one nation-wide register study providing some additional data on LDITR. Pooling all cohort studies, the percentages of non-responders during re-treatment with lithium ranged from 3.6 to 27.7%, with an average of 17.3%. Non-responsiveness was associated with longer duration of lithium treatment before discontinuation, longer duration of bipolar disorder before start of lithium, faster tapering off lithium, and longer duration of discontinuation.

CONCLUSIONS

There may be a subgroup in whom lithium discontinuation-induced treatment refractoriness exists. However, the vast majority of people respond when lithium is restarted. Moreover, it may be necessary to continue lithium beyond the first relapses to restore long-term prophylactic efficacy.

Old drug, new data

New data have emerged over the past 10 years regarding the efficacy and mechanisms of action of lithium. This article briefly summarises the evidence for the use of lithium to treat affective disorders and psychosis, reviews its putative anti-suicidal effect, highlights new research on its mechanism of action and provides an update on some important side-effects and consequences of its use.

Decreased responsiveness following lithium discontinuation in bipolar disorder: A naturalistic observation study

Lithium is a cornerstone in treatment of bipolar disorder. Findings are conflicting as to whether acquired unresponsiveness occurs following the discontinuation. Retrospective life chart data were evaluated to investigate the incidence of loss of response. Sixty-five patients chosen from a larger cohort, followed with prospective life charts, who discontinued lithium and had a second lithium treatment. Patients who had at least 2 mood episodes when they were drug naïve to describe the natural frequency of illness and 3 mood episodes before the discontinuation were included. The type of response was defined as excellent, partial, or poor according to mirror design method. Eighteen of 65 patients (27.6%) had a decreased response to lithium following its discontinuation. Nine of these patients (13.8%) were unresponsive and nine patients (13.8%) had attenuated response to second lithium treatment. The mean time of discontinuation was longer in the patients who show decreased response (245.8+268.2 vs. 117.9+149.8 days, p=.01). Those who had episode recurrences during the discontinuation were more likely to show reduced responsiveness upon re-treatment. After discontinuation of lithium treatment, more than a quarter of the patients showed an attenuated response or unresponsiveness, and initial partial responders more likely to show unresponsiveness than excellent responders.

Does the "Silver Bullet" Lose its Shine Over the Time? Assessment of Loss of Lithium Response in a Preliminary Sample of Bipolar Disorder Outpatients

Background:

Though often perceived as a “silver bullet” treatment for bipolar disorder (BD), lithium has seldom reported to lose its efficacy over the time.

Objective:

The aim of the present study was to assess cases of refractoriness toward restarted lithium in BD patients who failed to preserve maintenance.

Method:

Treatment trajectories associated with re-instituted lithium following loss of achieved lithium-based maintenance in BD were retrospectively reviewed for 37 BD-I patients (median age 52 years; F:M=17:20 or 46% of the total) over an 8.1-month period on average.

Results:

In our sample only 4 cases (roughly 11% of the total, of whom F:M=2:2) developed refractoriness towards lithium after its discontinuation. Thirty-three controls (F:M=15:18) maintained lithium response at the time of re-institution. No statistically significant difference between cases and controls was observed with respect to a number of demographic and clinical features but for time spent before first trial ever with lithium in life (8.5 vs. 3 years; U=24.5, Z=-2.048, p=.041) and length of lithium discontinuation until new therapeutic attempt (5.5 vs. 2 years; U=8, Z=-2.927, p=.003) between cases vs. controls respectively. Tapering off of lithium was significantly faster among cases vs. controls (1 vs. 7 days; U=22, Z=-2.187), though both subgroups had worrisome high rates of poor adherence overall.

Conclusion:

Although intrinsic limitations of the present preliminary assessment hamper the validity and generalizability of overall results, stating the clinical relevance of the topic further prospective research is warranted. The eventual occurrence of lithium refractoriness may indeed be associated with peculiar course trajectories and therapeutic outcomes ultimately urging the prescribing clinicians to put efforts in preserving maintenance of BD in the absence of any conclusive research insight on the matter.

Outcome of mood stabilizer discontinuation in bipolar disorder after 5 years of euthymia

OBJECTIVE

The objective was to study the outcome of mood stabilizer discontinuation on recurrence in patients with bipolar disorder after at least 5 years of euthymia.

METHODS

Twenty-three patients diagnosed with bipolar affective disorder according to the International Classification of Diseases, 10th Revision Diagnostic Criteria for Research, receiving mood stabilizer prophylaxis for at least 5 years, had undergone planned discontinuation, and the rates and time to recurrence were studied.

RESULTS

Twenty (87%) of 23 patients had recurrence, and all of the episodes were manic. Kaplan-Meier survival analysis showed median time to recurrence following discontinuation of mood stabilizer prophylaxis was 10 months (SE, 6.06 months; 95% confidence interval, 0 to 21.89 months).

CONCLUSION

Four fifths of our patients had recurrence following discontinuation of mood stabilizer prophylaxis within 10 months.

The effectiveness of restarted lithium treatment after discontinuation: reviewing the evidence for discontinuation-induced refractoriness

OBJECTIVES

We sought to determine whether the risk of relapse in patients with bipolar disorder is higher after discontinuation and restart of lithium treatment as compared to continuous lithium treatment in these same patients.

METHODS

We conducted literature searches in the Pubmed, Embase, Cochrane, and PsycINFO databases with cross-reference checks. Relevant data were extracted and pooled for meta-analysis.

RESULTS

Five relevant studies were included for review, of which three studies qualified for the meta-analysis and included a total of 212 analyzed cases. Two studies found lithium to be less effective after discontinuation and reintroduction and three studies found no decreased effectiveness. The pooled odds ratio for the occurrence of one or more relapses after interruption of lithium treatment compared to continuous treatment was 1.40 (95% confidence interval: 0.85-2.31; p = 0.19).

CONCLUSIONS

Although studies are scarce, review and meta-analysis of the available literature does not provide convincing evidence that lithium is less effective when treatment is discontinued and restarted, compared to uninterrupted treatment.

Acquired lithium resistance revisited: discontinuation-induced refractoriness versus tolerance

BACKGROUND

While some patients fail to respond to lithium from the outset, others are initially responsive and then develop treatment resistance. These acquired forms of lithium resistance have received relatively little clinical attention.

METHODS

We review the literature on the two different forms of acquired treatment resistance lithium that occur following an initial good response to lithium-discontinuation-induced refractoriness and tolerance- and discuss the possible neurobiological mechanisms involved.

RESULTS

Multiple investigators have reported cases of discontinuation-induced refractoriness, where following a good long-term response, patients discontinue lithium, suffer a major recurrence, and then do not again respond as well or at all to lithium once it is reinstituted at previously effective doses. The development of tolerance has similarly been multiply documented where lithium doses are consistently maintained, but after an extended period of excellent responsiveness, affective episodes of increasing severity, frequency, or duration begin to break through. These two forms of acquired treatment resistance appear to have different underlying neurobiological mechanisms and require differential treatment strategies.

LIMITATIONS

Recognition of acquired forms of lithium resistance depends on careful case descriptions and longitudinal monitoring of patients who are usually treated naturalistically and not in controlled clinical trials.

CONCLUSION

To the extent that these forms of acquired lithium resistance can be better recognized and their development slowed, prevented, or ameliorated, it could yield substantial clinical and public health benefits in avoiding the morbidity and mortality that can accompany lithium non-responsive bipolar disorder.

The mechanisms of tolerance in antidepressant action

There is increasing awareness that, in some cases, long-term use of antidepressant drugs (AD) may enhance the biochemical vulnerability to depression and worsen its long-term outcome and symptomatic expression, decreasing both the likelihood of subsequent response to pharmacological treatment and the duration of symptom-free periods. A review of literature suggesting potential side effects during long treatment with antidepressant drugs was performed. Studies were identified electronically using the following databases: Medline, Cinahl, PsychInfo, Web of Science and the Cochrane Library. Each database was searched from its inception date to April 2010 using "tolerance", "withdrawal", "sensitization", "antidepressants" and "switching" as key words. Further, a manual search of the psychiatric literature has been performed looking for articles pointing to paradoxical effects of antidepressant medications. Clinical evidence has been found indicating that even though antidepressant drugs are effective in treating depressive episodes, they are less efficacious in recurrent depression and in preventing relapse. In some cases, antidepressants have been described inducing adverse events such as withdrawal symptoms at discontinuation, onset of tolerance and resistance phenomena and switch and cycle acceleration in bipolar patients. Unfavorable long-term outcomes and paradoxical effects (depression inducing and symptomatic worsening) have also been reported. All these phenomena may be explained on the basis of the oppositional model of tolerance. Continued drug treatment may recruit processes that oppose the initial acute effect of a drug. When drug treatment ends, these processes may operate unopposed, at least for some time and increase vulnerability to relapse. Antidepressant drugs are crucial in the treatment of major depressive episodes. However, appraisal and testing of the oppositional model of tolerance may yield important insights as to long-term treatment and achievement of enduring effects.

Tolerance to the prophylactic effects of carbamazepine and related mood stabilizers in the treatment of bipolar disorders

Tolerance development after successful long‐term treatment of bipolar disorder is under recognized, as are ways to prevent or show its occurrence or reverse it once it has occurred. We review the clinical literature which suggests that tolerance can develop to most treatment approaches in bipolar illness and present an animal model of tolerance development to anticonvulsant effects of carbamazepine or lamotrigine on amgydala‐kindled seizures. In this model tolerance does not have a pharmacokinetic basis, but is contingent upon the drug being present in the brain at the time of amygdala stimulation. The occurrence of seizures in the absence of drug is sufficient to reverse tolerance and re‐establish anticonvulsant efficacy. Based on the model, we hypothesize that some episode‐induced compensatory adaptive changes in gene expression fail to occur in tolerant subjects and that episodes off medication re‐induce these changes and renew drug effectiveness. Approaches that slow or reverse tolerance development in the animal model are reviewed so that they can be tested for their applicability in the clinic. Criteria for assessing tolerance development are offered in the hope that this will facilitate a more systemic literature about its prevalence, prevention, and reversal. Careful longitudinal monitoring of episode occurrence is essential to understanding tolerance development in the affective disorder and its treatment.

Lithium: updated human knowledge using an evidence-based approach. Part II: Clinical pharmacology and therapeutic monitoring

After a single dose, lithium, usually given as carbonate, reaches a peak plasma concentration at 1.0-2.0 hours for standard-release dosage forms, and 4-5 hours for sustained-release forms. Its bioavailability is 80-100%, its total clearance 10-40 mL/min and its elimination half-life is 18-36 hours. Use of the sustained-release formulation results in 30-50% reductions in peak plasma concentrations without major changes in the area under the plasma concentration curve. Lithium distribution to the brain, evaluated using 7Li magnetic resonance spectroscopy, showed brain concentrations to be approximately half those in serum, occasionally increasing to 75-80%. Brain concentrations were weakly correlated with serum concentrations. Lithium is almost exclusively excreted via the kidney as a free ion and lithium clearance is considered to decrease with aging. No gender- or race-related differences in kinetics have been demonstrated. Renal insufficiency is associated with a considerable reduction in renal clearance of lithium and is considered a contraindication to its use, especially if a sodium-poor diet is required. During the last months of pregnancy, lithium clearance increases by 30-50% as a result of an increase in glomerular filtration rate. Lithium also passes freely from maternal plasma into breast milk. Numerous kinetic interactions have been described for lithium, usually involving a decrease in the drug's clearance and therefore increasing its potential toxicity. Clinical pharmacology studies performed in healthy volunteers have investigated a possible effect of lithium on cognitive functions. Most of these studies reported a slight, negative effect on vigilance, alertness, learning and short-term memory after long-term administration only. Because of the narrow therapeutic range of lithium, therapeutic monitoring is the basis for optimal use and administration of this drug. Lithium dosages should be adjusted on the basis of the serum concentration drawn (optimally) 12 hours after the last dose. In patients receiving once-daily administration, the serum concentration at 24 hours should serve as the control value. The efficacy of lithium is clearly dose-dependent and reliably correlates with serum concentrations. It is now generally accepted that concentrations should be maintained between 0.6 and 0.8 mmol/L, although some authors still favour 0.8-1.2 mmol/L. With sustained-release preparations, and because of the later peak of serum lithium concentration, it is advised to keep serum concentrations within the upper range (0.8-1 mmol/L), rather than 0.6-0.8 mmol/L for standard formulations. It is controversial whether a reduced concentration is required in elderly people. The usual maintenance daily dose is 25-35 mmol (lithium carbonate 925-1300 mg) for patients aged <40 years; 20-25 mmol (740-925 mg) for those aged 40-60 years; and 15-20 mmol (550-740 mg) for patients aged >60 years. The initial recommended dose is usually 12-24 mmol (450-900 mg) per day, depending on age and bodyweight. The classical administration schedule is two or three times daily, although there is no strong evidence in favour of a three-times-daily schedule, and compliance with the midday dose is questionable. With a modern sustained-release preparation, the twice-daily schedule is well established, although one single evening dose is being recommended by a number of expert panels.

Pediatric bipolar disease: current and future perspectives for study of its long-term course and treatment

AIM AND METHODS

Findings from recent long-term, prospective longitudinal studies of the course, outcome and naturalistic treatment of adults with bipolar illness are highlighted as background for long-term developmental study of pediatric bipolar illness.

RESULTS

Accumulating knowledge of bipolar illness in adults underscores a high risk for multiple recurrences through the lifespan, significant medical morbidity, high rates of self-harm, economic and social burden and frequent treatment resistance with residual symptoms between major episodes. At present, there is no empirical foundation to support any assumption about the long-term course or outcome of bipolar illness when it arises in childhood or adolescence, or the effects of conventional pharmacotherapies in altering its course and limiting potentially adverse outcomes. The proposed research articulates specific descriptive aims that draw on adult findings and outlines core methodological requirements for such an endeavor.

CONCLUSIONS

Innovations in the description and quantitative analysis of prospective longitudinal clinical data must now be extended to large, systematically ascertained pediatric cohorts recruited through multicenter studies if there is to be a meaningful scientific advance in our knowledge of the enduring effects of bipolar illness and the potential value of contemporary approaches to its management.

Combination lithium and divalproex sodium in pediatric bipolar symptom re-stabilization

OBJECTIVE

It has been reported that bipolar disorder may become less responsive to previously effective treatment with each symptomatic relapse. The primary goal of this study was to assess the rate of re-stabilization after the resumption of lithium (Li) plus divalproex (DVPX) following relapse on either agent as monotherapy.

METHOD

This is a prospective, 8-week, open-label outpatient Li/DVPX combination therapy trial. Patients ages 5 to 17 years with bipolar disorder type I or II, who had achieved symptom remission with Li/DVPX combination therapy and subsequently relapsed during treatment with Li or DVPX monotherapy were enrolled between January 1999 and January 2003.

RESULTS

Thirty-eight patients with a mean age of 10.5 years entered the study. Thirty-four (89.5%) patients responded to treatment with Li/DVPX mood stabilizer therapy alone, but four patients required adjunctive antipsychotic treatment to address residual symptomatology. Overall, reinitiation of Li/DVPX combination therapy was well tolerated with no subjects discontinuing because of a medication-related adverse event.

CONCLUSIONS

It appears that most youths with bipolar disorder who stabilize on combination Li/DVPX therapy and subsequently relapse during monotherapy can safely and effectively be re-stabilized with the reinitiation of Li/DVPX combination treatment.

The effect of lithium in bipolar disorder: a review of recent research evidence

Recently published clinical research on lithium is briefly reviewed. The antimanic effect of lithium is supported by recent evidence. It is confirmed that a drastic reduction of affective morbidity is very frequent in bipolar patients receiving lithium prophylaxis regularly for several years, but that the impact of prophylaxis on the course of bipolar disorder is significantly limited by the high drop-out rate. Lithium does seem to be efficacious also in bipolar disorder with mood-incongruent psychotic features or with rapid cycling. The effect of lithium prophylaxis does not seem to decrease over time, at least in the large majority of patients. The recurrence risk is increased in the months following lithium discontinuation. Lithium seems to exert an antisuicidal effect in bipolar patients.

The significance of psychotic features in manic episodes: a report from the NIMH collaborative study

BACKGROUND

Psychotic features in the context of major depressive syndromes have correlates in symptom severity, acute treatment response and long-term prognosis. Little is known as to whether psychotic features have similar importance when they occur within manic syndromes.

METHODS

These data derive from a multi-center, long-term follow-up of patients with major affective disorder. Raters conducted follow-up interviews at 6-month intervals for the first 5 years and annually thereafter. A sub-set of probands participated in a family study in which all available, adult, first-degree relatives were interviewed as well.

RESULTS

Of 139 who entered the study in an episode of mania, 90 patients had psychotic features. Symptom severity ratings at intake were more severe for this group. Though time to first recovery and time to first relapse did not distinguish the groups, psychotic features were associated with a greater number of weeks ill during follow-up and the strength of this association was similar to that seen for psychotic features within depressed patients described in an earlier publication. Patients with psychotic mania at intake did not differ significantly from those with nonpsychotic mania by response to acute lithium treatment, suicidal behavior during follow-up, or risks for affective disorder among first-degree relatives. Psychotic features within manic syndromes were not associated with high psychosis ratings during follow-up. In contrast, when psychotic features accompanied depressive syndromes, they strongly predicted the number of weeks with psychosis during follow-up, particularly among individuals whose episodes at intake were less acute.

CONCLUSIONS

As with major depressive syndromes, psychotic features in mania are associated with greater symptom severity and higher morbidity in the long-term. Psychotic features are much less predictive of future psychosis when they occur within a manic syndrome than when they occur within a depressive syndrome.

Emerging trends in the treatment of rapid cycling bipolar disorder: a selected review

Recent evidence suggests that lithium therapy (even as supplemented by antidepressants and neuroleptics) is inadequate for the majority of patients with bipolar illness, and particularly those with rapid cycling. Valproate and carbamazepine have emerged as adjuncts and alternatives, but they, too, often require additional approaches with lithium, thyroid hormones, and other putative mood stabilizers, including nimodipine (and related dihydropyridine calcium channel blockers), lamotrigine, gabapentin, topiramate, and the atypical neuroleptics. Evaluating how these agents and the unimodal antidepressants are optimally applied and sequenced in the treatment of bipolar illness with its multiple subtypes, patterns and comorbidities will require much future investigation and the development of new methodological clinical trial approaches.

Psychotropic drug prescription patterns among patients with bipolar I disorder

INTRODUCTION

Combination treatment, rather than monotherapy, is prevalent in the treatment of subjects with bipolar disorder, probably due to the complex and phasic nature of the illness. In general, prescription patterns may be influenced by the demographic characteristics of patients as well. We evaluated prescription patterns and the influence of demographic variables on these patterns in a voluntary registry of subjects with bipolar disorder.

METHODS

A subset of data from a larger voluntary registry was extracted for demographic variables and psychotropic medication use that had been reported in the month prior to registration by ambulatory, non-hospitalized subjects with bipolar I disorder in 1995/96 (n = 457).

RESULTS

Among the thymoleptic agents, lithium was prescribed in over 50% of subjects, valproate in approximately 40%, and carbamazepine in 11% of subjects. Eighteen percent of subjects had no prescription for thymoleptic agents. Nearly one-third of all subjects were receiving antipsychotic agents, of whom two-thirds were receiving the traditional neuroleptic agents. More than half of all subjects were receiving concomitant antidepressants, of whom nearly 50% received the SSRI antidepressants and nearly 25% received buproprion. Approximately 40% of subjects received benzodiazepines. Only 18% of subjects received monotherapy, and nearly 50% received three or more psychotropic agents. In general, no associations were noted between demographic parameters including age, gender, marital or educational status, and psychotropic prescriptions.

CONCLUSION

Consistent with the anecdotal reports, these data confirm that combination treatment is far more common than monotherapy. Demography appears to have a minimal impact on cross-sectional prescription patterns in subjects with bipolar disorder. Given that combination treatments are the rule rather than the exception, we should strive to achieve rational, yet pragmatic, treatment guidelines and algorithms to minimize the risks while maximizing the benefits of these combination treatments for patients with bipolar disorder.

The impact of lithium prophylaxis on the course of bipolar disorder: a review of the research evidence

A critical review is provided of the available research evidence concerning the efficacy and effectiveness of lithium prophylaxis in bipolar disorder. It is emphasized that, in spite of the limitations of available placebo-controlled trials and naturalistic studies, lithium is the only drug whose prophylactic activity in bipolar disorder is convincingly proved, and remains the first-choice medication in the long-term treatment of bipolar patients. The impact of lithium prophylaxis is likely to be less significant on atypical and comorbid cases of bipolar disorder than in typical manic depressive illness, but the superiority of other medications over lithium in the long-term treatment of those cases is at present not convincingly proved by research. Currently available research evidence does not seem to support the idea that lithium exerts its prophylactic effect on relapses but not on recurrences of bipolar disorder. Clinicians should be aware of the fact that the drop-out rate in bipolar patients receiving long-term lithium prophylaxis is high even if treatment surveillance is accurate, and that complete suppression of recurrences is a relatively rare outcome of prophylaxis.

Methodological considerations for the development of new treatments for bipolar disorder

Lithium has been the drug of choice in treating bipolar disorder for 50 years and, therefore, patterns of response associated with its use define what we expect from treatment. Although efforts to establish some other agents as antimanic have been successful, it is difficult to assess their overall efficacy in relation to that of lithium without a better understanding of inclusion/exclusion criteria, subtypes, definitions of remission, relapse and recurrence, and duration of study. All of these factors need to be carefully addressed to identify the most important clinical targets for new drug development. Additional relevant information emerges from studies on combinations of mood stabilisers, efficacy of antimanic agents in different patient populations, analysis of rates of drop-out, non-compliance, suicide, drug abuse, and discontinuation especially with long-term treatment. Agents other than lithium that are effective in the acute phase treatment are still not well characterised as mood stabilisers. New agents need to be evaluated in the context of long-term treatment and the targeting of specific components of the syndrome beyond mania.

Discontinuing lithium maintenance treatment in bipolar disorders: risks and implications

OBJECTIVE

To review research findings on clinical effects of discontinuing lithium maintenance treatment.

METHODS

Data from studies reported since 1970 plus our recent findings were updated.

RESULTS

Discontinuing lithium maintenance treatment led to marked increases of early affective morbidity and suicidal risk. Gradual discontinuation markedly reduced early recurrences of mania or depression, did so more in bipolar II than I disorder patients, and also tended to reduce suicidal risk. Similar effects were found in pregnant and nonpregnant women after lithium discontinuation. Long-term retreatment with lithium following discontinuation was only slightly less effective than in initial trials.

CONCLUSIONS

Recurrences increased sharply soon after discontinuing lithium, but were markedly limited and not merely delayed, by slow discontinuation. Similar reactions may follow discontinuation of other drugs, evidently as responses to long-term pharmacodynamic adaptations. Discontinuing treatment is not equivalent to not-treating. Post-discontinuation relapse risk has implications for the design, management, and interpretation of protocols involving discontinuation of long-term treatments that should be considered in both clinical management and research.

Differential effect of number of previous episodes of affective disorder on response to lithium or divalproex in acute mania

OBJECTIVE

The authors investigated the relationship between number of lifetime episodes of affective disorder and the antimanic response to lithium, divalproex, or placebo.

METHOD

The subjects were 154 of the 179 inpatients with acute mania who entered a 3-week parallel group, double-blind study. The primary efficacy measure was the manic syndrome score from the Schedule for Affective Disorders and Schizophrenia. The relationship between improvement and number of previous episodes was investigated by using nonlinear regression analysis.

RESULTS

An apparent transition in the relationship between number of previous episodes and response to antimanic medication occurred at about 10 previous episodes. For patients who had experienced more episodes, response to lithium resembled the response to placebo but was worse than response to divalproex. For patients who had experienced fewer episodes, however, the responses to lithium and divalproex did not differ and were better than the response to placebo. This differential response pattern was not related to rapid cycling or mixed states.

CONCLUSIONS

A history of many previous episodes was associated with poor response to lithium or placebo but not to divalproex.