Lamotrigine in the treatment of schizoaffective disorder

Lamotrigine Uses in Psychiatric Practice

BACKGROUND

Lamotrigine (LAM), an antiepileptic, with panoply of indications and uses in neurology, is FDA approved, in psychiatry, for bipolar prophylaxis. Apart from this indication, trend of its use in psychiatry is on the rise addressing a multitude of disorders.

STUDY QUESTION

LAM remains one of only few psychotropic drugs with antiglutamate activity. This might render LAM a potential therapeutic option in treatment-resistant major psychiatric disorders. We reviewed LAM pharmacology and its diverse indications while examining the extant evidence.

METHODS

EMBASE, Ovid MEDLINE, PubMed, Scopus, Web of Science, and Cochrane Database of Systemic Reviews were searched for all relevant studies up to date of June 2016.

RESULTS

Sound evidence supports use of LAM for acute bipolar depression and prophylaxis, treatment-resistant schizophrenia, treatment-resistant obsessive-compulsive disorder, posttraumatic stress disorder, depersonalization disorder, and affective dysregulation and behavioral dyscontrol domains of borderline personality disorder. Less compelling evidence is present for use in behavioral and psychological symptoms of dementia and neuropsychiatric sequelae of traumatic brain injury. No evidence supports use in autism spectrum disorder or acute unipolar depression.

CONCLUSIONS

LAM is an important addition to the psychopharmacological armamentarium. Level of evidence supporting the use of LAM in off-label indications is highly variable, and hence, sound clinical judgment is necessary for its proper use and placement in real-life psychiatric practice and psychopharmacotherapy algorithms.

Use and safety of antiepileptic drugs in psychiatric inpatients-data from the AMSP study

The psychiatric utilization patterns and risks of antiepileptic drugs (AEDs) were assessed by using data from the drug safety programme Arzneimittelsicherheit in der Psychiatrie over the time period 1993-2013. In a total of 432,215 patients, the main indications for AED use were acute mania, schizoaffective disorder, and schizophrenic and organic psychoses. Valproic acid (VPA) was the most common substance across all of those groups, reaching administration rates of up to 50% since 2005, at which time carbamazepine (CBZ) administration consistently dropped below a rate of 10%. Lamotrigine (LTG) and pregabalin (PGB) increased in relevance after 2005 and 2010, respectively (with administration rates of up to 9%), whereas oxcarbazepine (OXC) was least prevalent (<3%). The mean rates of severe adverse drug reactions (ADRs) ranged from 6 cases per 1000 patients treated (VPA) to 19/1000 (OXC) and were significantly lower with treatment with VPA compared to OXC and CBZ. Hyponatremia was the leading ADR during treatment with OXC; severe allergic skin reactions were most often observed during treatment with CBZ and LTG, and severe oedema was most common during treatment with PGB. Severe hyponatremia induced by OXC was observed significantly more often in female patients than in male patients.

Down-Regulation of Hippocampal Genes Regulating Dopaminergic, GABAergic, and Glutamatergic Function Following Combined Neonatal Phencyclidine and Post-Weaning Social Isolation of Rats as a Neurodevelopmental Model for Schizophrenia

BACKGROUND

Dysfunction of dopaminergic, GABAergic, and glutamatergic function underlies many core symptoms of schizophrenia. Combined neonatal injection of the N-methyl-D-aspartate (NMDA) receptor antagonist, phencyclidine (PCP), and post-weaning social isolation of rats produces a behavioral syndrome with translational relevance to several core symptoms of schizophrenia. This study uses DNA microarray to characterize alterations in hippocampal neurotransmitter-related gene expression and examines the ability of the sodium channel blocker, lamotrigine, to reverse behavioral changes in this model.

METHODS

Fifty-four male Lister-hooded rat pups either received phencyclidine (PCP, 10mg/kg, s.c.) on post-natal days (PND) 7, 9, and 11 before being weaned on PND 23 into separate cages (isolation; PCP-SI; n = 31) or received vehicle injection and group-housing (2-4 per cage; V-GH; n = 23) from weaning. The effect of lamotrigine on locomotor activity, novel object recognition, and prepulse inhibition of acoustic startle was examined (PND 60-75) and drug-free hippocampal gene expression on PND 70.

RESULTS

Acute lamotrigine (10-15mg/kg i.p.) reversed the hyperactivity and novel object recognition impairment induced by PCP-SI but had no effect on the prepulse inhibition deficit. Microarray revealed small but significant down-regulation of hippocampal genes involved in glutamate metabolism, dopamine neurotransmission, and GABA receptor signaling and in specific schizophrenia-linked genes, including parvalbumin (PVALB) and GAD67, in PCP-SI rats, which resemble changes reported in schizophrenia.

CONCLUSIONS

Findings indicate that alterations in dopamine neurotransmission, glutamate metabolism, and GABA signaling may contribute to some of the behavioral deficits observed following PCP-SI, and that lamotrigine may have some utility as an adjunctive therapy to improve certain cognitive deficits symptoms in schizophrenia.

Anticonvulsant drugs in bipolar disorder

Although much progress has been made in successfully treating bipolar disorder, there is increasing awareness of the limitations of traditional treatment regimens such as lithium and neuroleptics. The large family of anticonvulsant drugs, however, appears to be capable of providing new treatment options, not only as medication of second choice in patients refractory to treatment, but often as a treatment standard with high efficacy and low incidence of side effects. Besides established mood stabilizers such as carbamazepine and valproate, new antiepileptic drugs are entering the field with promising initial results in the treatment of bipolar patients. Furthermore, bringing to light the mechanisms of action of anticonvulsants and the similarities between anticonvulsants effective in bipolar disorder may also deepen our understanding of the pathophysiological basis of the disorder.

What we know and what we don't know about the treatment of schizoaffective disorder

Schizoaffective disorder (SAD) is a chronic, severe and disabling illness consisting on the concurrent presentation of symptoms of schizophrenia and affective disorders (depression and/or mania). Evidence for the treatment of SAD mostly derives from studies based on mixed samples (i.e. schizophrenic and schizoaffective patients) or on extrapolations from studies on schizophrenia or bipolar disorder. The objective of the present review is to systematically consider and summarize the best evidence-based approaches to the treatment of SAD and extensively point out the gap between treatment research and clinical practice of this disorder. The complex problem of controlling the pleomorphic presentation of SAD's syndromic construct is reflected in the lack of evidence on key topics, including: diagnostic consistency, pharmacological approaches (mood stabilizers, antidepressants, both in acute and maintenance treatment as well as their possible combination), and the adjunctive role of psychosocial and biophysical interventions. Finally, treatment strategies for SAD, both unipolar and bipolar type, are proposed.

Psychotropic effects of antiepileptic drugs

Antiepileptic drugs are important psychotropic agents that are commonly used to treat psychiatric disorders. The behavioral effects of antiepileptic drugs may differ between epilepsy and psychiatric patient populations. Randomized, double-blind, controlled data on the psychotropic efficacy of antiepileptic drugs are limited mainly to bipolar disorder.

Antidepressant-like effect of lamotrigine is reversed by veratrine: a possible role of sodium channels in bipolar depression

Lamotrigine has been found to be efficacious in the acute management of bipolar depression and long-term management of bipolar disorder, especially in delaying depressive recurrence, either as monotherapy or as adjunctive therapy. Lamotrigine is also an antiepileptic drug, and is efficient in the treatment of focal epilepsies. It is thought to act by inhibition of glutamate release through blockade of voltage-sensitivity sodium channels and stabilization of the neuronal membrane.

OBJECTIVES

The scope of this study was to determinate if sodium channels are important for lamotrigine and other antidepressant to exert their antidepressant-like function.

METHODS

This study assessed the effects of veratrine, a Na(+) channel opener on antidepressant effect of lamotrigine and others antidepressants: two tricyclic antidepressants (TCAs): imipramine, a mixed serotonergic noradrenergic reuptake inhibitor, desipramine, a specific noradrenergic reuptake inhibitor and a SSRI: paroxetine, the most potent selective serotonergic reuptake inhibitor, using an animal model of depression, the forced swimming test. Veratrine (0.125 mg/kg) and lamotrigine (16, 32 mg/kg) or antidepressants (16, 32 mg/kg) were given i.p. 45 and 30 min, respectively, before the test.

RESULTS

We observed that when combined with veratrine the antidepressant-like effect of lamotrigine was reversed, but the antidepressant-like effect of the imipramine, desipramine and paroxetine was not changed, indicating that the mechanism of action of lamotrigine is different from that of antidepressants.

Lamotrigine in psychiatry: pharmacology and therapeutics

Following the introduction of lamotrigine in 1994 as a treatment for epilepsy in the United States, the drug has seen progressively greater application in psychiatry, particularly as a treatment for bipolar disorder. This review critically evaluates the support for lamotrigine use across a broad range of psychiatric disorders as well as discuss its pharmacology, side-effect profile, and interactions with other medications.

Cognitive side effects of antiepileptic drugs

Antiepileptic drugs produce global changes in the excitation levels in the central nervous system and often lead to cognitive and behavioral deficits. These deficits vary and must be considered independently in every patient. A number of consistent risk factors have been established. Polypharmacy and high blood levels of an antiepileptic drug (AED) increase the risk of cognitive side effects. Different effects have been demonstrated for some AEDs, but comparative data are incomplete across all of them. Other factors such as patient age and type/frequency of seizures may also be important contributors to the patient's cognitive state. AEDs can have positive or negative effects on mood, providing another consideration in choosing the course of treatment.

The evolution of antiepileptic drugs for mood stabilization and their main mechanisms of action

Although much progress has been made in successfully treating bipolar disorder, there is increasing awareness of the limitations of traditional treatment regimes, such as lithium or antipsychotics and the possible beneficial use of antiepileptic drugs. After the first generation of antiepileptic drugs such as phenytoin and clonazepam, the second generation is comprised of the frequently-used substances carbamazepine/oxcarbazepine and valproate. Lamotrigine, gabapentin, tiagabine, levetiracetam, zonisamide and topiramate will represent the third generation 5 years from now. Drugs such as retigabine might represent the next generation. However, the efficacy of antiepileptic drugs investigated in the treatment of bipolar disorder differs and most promising effects are seen in combination therapy with mood stabilizers. The authors review the main mechanisms of action of these drugs which may, in turn, improve our understanding of the pathophysiology of bipolar disorder.

Newer antiepileptic drugs in bipolar disorder: rationale for use and role in therapy

Antiepileptic drugs (AEDS) are used regularly in the treatment of patients with bipolar disorders. Carbamazepine and valproic acid (sodium valproate) are effective as antimanic treatments, and the success of these medications has prompted investigation of other AEDs as possible treatments in patients with mood disorders. Lamotrigine appears to be the most promising of the newer AEDs with respect to effects in mood disorders. Current evidence suggests efficacy of this drug both as monotherapy and as an adjunctive agent in bipolar depression, and studies are underway to clarify its efficacy in mood stabilisation and rapid cycling, as currently available data are equivocal. Use of gabapentin is not as well supported in the literature, although data from open trials using it as an adjunctive agent suggest that it may be helpful in patients with bipolar depression. There have been some open trials and case reports supporting the use of topiramate as an adjunctive agent for the treatment of mania; however, data from controlled trials are not yet available. Further controlled trials of lamotrigine, gabapentin or topiramate as monotherapy and adjunctive treatment are needed to clarify their potential roles in the treatment of patients with mood disorders.

Psychiatric uses of antiepileptic treatments

Antiepileptic drugs (AEDs) possess potent negative or positive psychotropic effects. Clear evidence of benefit exists for valproate, carbamazepine, and lamotrigine in bipolar disorder. Reports of benefit from various AEDs in mood, anxiety, impulse control, and personality disorder are reviewed. Further research is needed to clarify which patients are likely to benefit. Clinicians must closely attend to the ongoing risk/benefit analysis and consider possible iatrogenic worsening of neuropsychiatric symptoms.

Lamotrigine update and its use in mood disorders

OBJECTIVE

To provide a qualitative, systematic update and review of the pharmacology, pharmacokinetics, efficacy in mood disorders, adverse effects, and costs of lamotrigine.

DATA SOURCES

Citations obtained from MEDLINE searches (1985-September 2001) using lamotrigine as a text word, articles identified in reference lists of pertinent articles, abstracts presented at conferences, and research data from GlaxoSmithKline.

DATA EXTRACTION

English-language articles were considered for possible inclusion. Each title and abstract was examined to determine whether the publication contained up-to-date information relevant to the objective. Twenty clinical trials that provided data on response rates in mood disorders were tabulated.

DATA SYNTHESIS

Lamotrigine's primary action is to modulate voltage-gated sodium channels. Evidence suggests that it decreases glutamate transmission, directly reduces calcium influx, mildly blocks transmitter reuptake, and alters intracellular mechanisms of resting transmitter release. The average half-life of lamotrigine is approximately 24 hours, but decreases to approximately 7.4 hours when used concurrently with phenytoin, and increases to approximately 59 hours with valproic acid. Seven of the 20 clinical trials were randomized, double-blind, and controlled. Existing data are inadequate to evaluate lamotrigine use in major depression. The pooled response rates for patients with depressed, manic, mixed, and rapid cycling bipolar disorder were similar, ranging from 52% to 63%. Adverse effects are infrequent when the drug is used alone, but become more frequent when lamotrigine is combined with other anticonvulsants. While most rashes are mild, approximately 1 in 500 patients develops exfoliative dermatitis. A slow upward dose titration is recommended to reduce the incidence of serious rash, but this may delay the attainment of adequate dosage for 6 weeks. Lamotrigine has positive effects on cognitive function, but occasionally produces insomnia. Lamotrigine costs 2-4 times more than lithium, carbamazepine, and generic valproic acid.

CONCLUSIONS

When efficacy, adverse effects, and cost are considered, lamotrigine should probably be reserved as a second-line agent for bipolar depression.

Lamotrigine induced selective changes in 5-HT(1A) receptor mediated response in rat brain

A new anticonvulsant drug lamotrigine (LTG) has recently been reported to be effective in treating patients with bipolar affective disorder, depression and schizoaffective disorder, suggesting that it is a mood stabilizer. However, the mechanism of action underlying its efficacy in mood disorders is not understood. This study examined the in vivo effect of LTG on 5-HT(1A) receptor-mediated adenylyl cyclase (AC) response in regions of rat brain, as this pathway has been implicated in the therapeutic action of various classes of mood stabilizers. The density of 5-HT(1A) receptors was measured by radioligand binding assay using [(3)H]8-OH-DPAT (0.05-0.8nM) in frontal cortex and hippocampus of rats treated orally with LTG (5mg/kg) for 7 days. AC activity was assayed using [(3)H]ATP. The oral administration of LTG significantly decreased the density of cortical (50%, P<0.001) but not hippocampal 5-HT(1A) receptors, without significant change in the affinity of [(3)H]8-OH-DPAT to 5-HT(1A) receptor in these regions. There was no significant alteration in basal or forskolin-stimulated AC activity in either of regions. However, a significant decrease (P<0.01) in the inhibition of forskolin-stimulated AC activity by 8-OH-DPAT was observed only in cortical membranes of LTG treated rats when compared to control. These results suggest that one mode of action of LTG may be by the downregulation of cortical 5-HT(1A) receptor-mediated AC response.

Lamotrigine reduces spontaneous and evoked GABAA receptor-mediated synaptic transmission in the basolateral amygdala: implications for its effects in seizure and affective disorders

Lamotrigine (LTG) is an antiepileptic drug that is also effective in the treatment of certain psychiatric disorders. Its anticonvulsant action has been attributed to its ability to block voltage-gated Na(+) channels and reduce glutamate release. LTG also affects GABA-mediated synaptic transmission, but there are conflicting reports as to whether inhibitory transmission is enhanced or suppressed by LTG. We examined the effects of LTG on GABA(A) receptor-mediated synaptic transmission in slices from rat amygdala, a brain area that is particularly important in epileptogenesis and affective disorders. In intracellular recordings, LTG (100 microM) reduced GABA(A) receptor-mediated IPSPs evoked by electrical stimulation in neurons of the basolateral nucleus. In whole-cell recordings, LTG (10, 50 and 100 microM) decreased the frequency and amplitude of spontaneous IPSCs, as well as the amplitude of evoked IPSCs, but had no effect on the kinetics of these currents. LTG also had no effects on the frequency, amplitude or kinetics of miniature IPSCs recorded in the presence of TTX. These results suggest that in the basolateral amygdala, LTG suppresses GABA(A) receptor-mediated synaptic transmission by a direct and/or indirect effect on presynaptic Ca(++) influx. The modulation of inhibitory synaptic transmission may be an important mechanism underlying the psychotropic effects of LTG.

Emerging options in the treatment of bipolar disorders

Bipolar disorder is a common and severe condition, and has a clinical outcome that is frequently sub-optimal. Only a small number of therapeutic options are currently available for the disorder. A growing range of novel therapeutic options for the treatment of bipolar disorder are under investigation. These include the anticonvulsants, atypical antipsychotics and options such as the omega-3 fatty acids and transcranial magnetic stimulation. Of the anticonvulsants, lamotrigine is currently the agent for which the greatest amount of controlled clinical data is accumulating, particularly in the depressed and rapid cycling phases of the illness. Olanzapine is currently the atypical antipsychotic with the largest body of evidence in mania, although data is emerging on other atypical antipsychotics including risperidone and ziprasidone. Data regarding the atypical agents in other phases of the illness are awaited. The options available for this difficult to treat condition is increasing with the new range of agents.

Behavioural effects of the new anticonvulsants

Of the 9 new anticonvulsants that have been marketed recently in the UK or US, a number appear to have either adverse or beneficial effects on behaviour. There is now a considerable database of information, in terms of the number of patients treated and/or the number of published reports, on vigabatrin, lamotrigine, gabapentin and topiramate. Oxcarbazepine has been available in some centres for several years and there is extensive experience with the drug in Scandinavia. It appears that the profile of adverse and beneficial effects is similar to that of carbamazepine. Behavioural effects have probably been greatest with vigabatrin, with psychosis, depression and other behavioural problems recorded, but the use of this drug has been limited because of the concern about visual field constriction. The cognitive and behavioural effects of topiramate have caused concern, but these may be much less of a problem if lower starting dosages and escalation rates are used. Psychosis and depression have been associated with topiramate, as they have with another carbonic anhydrase inhibiting drug, zonisamide. Although zonisamide has been used for many years in Japan and Korea, experience elsewhere with this drug is currently very limited. Gabapentin seems to be less associated with adverse behavioural effects than some of the other new anticonvulsant drugs. The reports of behavioural disturbance with gabapentin in children may be related to dose escalation. Behavioural disturbance as a direct result of lamotrigine seems to be uncommon, although indirect effects on behaviour, through the so-called 'release phenomenon' from improved seizure control and consequent ability to misbehave, can occur. Positive behavioural effects have been described with several of the new anticonvulsants, particularly gabapentin, lamotrigine and oxcarbazepine; all of these drugs may have mood-levelling effects that could be of value in treating affective disorders. The information on tiagabine and levetiracetam is too limited to allow any firm conclusions to be drawn with regard to positive or negative behavioural effects. When interpreting reports of behavioural changes with anticonvulsants, it is important to avoid attributing the effect to the drug when one or more of the other multiple causes of behavioural disturbance in people with epilepsy may be responsible or when an indirect effect such as 'forced normalisation' may be the cause. Many of the published studies are retrospective and unblinded rather than double-blind, placebo-controlled, prospective trials, implying that much of the data must be interpreted with caution at this stage.

Topiramate monotherapy in the maintenance treatment of bipolar I disorder: effects on mood, weight and serum lipids

Topiramate is a newly developed anticonvulsant agent with possible mood-stabilizing properties. Little is known about the short- and long-term effects of topiramate monotherapy in bipolar disorder. We here present the case of a 60-year-old female bipolar patient who received topiramate alone as maintenance treatment after recovering from euphoric mania. During 7 months, she was free from new manic symptomatology and she was able to reduce her overweight by 16.5 kg. The patient who is known to have a strongly hyperthymic temperament described symptoms of fatigue and sedation and eventually discontinued topiramate monotherapy. When she presented again in our bipolar clinic, severe euphoric mania had developed. After hospitalization, she slowly responded to oral sodium valproate loading plus zotepine. Her weight increased again and so did her triglyceride serum levels. Topiramate treatment and discontinuation did not seem to affect cholesterol serum levels.

Lamotrigine Monotherapy Improves Depressive Symptoms in Epilepsy: A Double-Blind Comparison with Valproate

Depressive symptoms are highly prevalent in patients with epilepsy. The antiepileptic drug lamotrigine has been shown to be an effective treatment for the depressive phase of bipolar disorder and to enhance mood and well-being in epilepsy patients. The effects of lamotrigine monotherapy on depressive symptoms in epilepsy have not been evaluated to date in a controlled clinical trial. A recently completed double-blind epilepsy trial comparing the effects of lamotrigine monotherapy and valproate monotherapy on weight change incorporated a battery of standard mood assessments. Mean screening Beck Depression Inventory scores showed that both lamotrigine and valproate groups suffered from mild depression at baseline. Lamotrigine monotherapy was reliably associated with earlier and larger improvements than valproate in mood assessed with the Beck Depression Inventory, the Cornell Dysthymia Rating Scale, and the Profile of Mood States. Considered in the context of other data showing lamotrigine's antidepressant efficacy in bipolar depression, these results suggest that lamotrigine improves mood in mildly depressed patients with epilepsy. Lamotrigine may be particularly useful in treating epilepsy patients with comorbid depression, the most common psychiatric illness in epilepsy.

Lamotrigine for the treatment of bipolar disorder

OBJECTIVE

To describe the available data regarding the clinical efficacy of lamotrigine for the treatment of bipolar disorder.

SUMMARY

Anticonvulsants have emerged as alternative mood-stabilizing agents for patients with bipolar disorder who do not respond to lithium. Data regarding the efficacy of lamotrigine have been generated primarily from case reports, small open trials, and one large, randomized, placebo-controlled trial. These reports suggest that lamotrigine may be effective for the management of bipolar disorder.

CONCLUSIONS

Although current data are limited, treatment-refractory patients with bipolar disorder may benefit from lamotrigine therapy. Several studies are currently underway to determine the appropriate role of lamotrigine in the treatment of bipolar disorder.