Synergistic Effects of Tranylcypromine and NRF2 Inhibitor: A Repurposing Strategy for Effective Cancer Therapy

Drug repurposing has emerged as an attractive strategy for accelerating drug discovery for cancer treatment. In this study, we investigated combining Tranylcypromine (TCP) with a number of well-characterized drugs. Among these combinations, NRF2 inhibitor (ML385) exhibited synergistic effects in combination with TCP. Specifically, our results showed that the combination of TCP and ML385 resulted in a significant reduction in tumor proliferation while neither drug affected cancer cell growth meaningfully on its own. While further studies are needed to understand fully the extent of the synergistic efficacy, the underlying respective mechanisms and the potential side effects of this approach, our study has yielded a promising start for the development of an effective combination cancer therapy.

Classics in Chemical Neuroscience: Selegiline, Isocarboxazid, Phenelzine, and Tranylcypromine

The discovery of monoamine oxidase inhibitors (MAOIs) in the 1950s marked a significant breakthrough in medicine, creating a powerful new category of drug: the antidepressant. In the years and decades that followed, MAOIs have been used in the treatment of several pathologies including Parkinson's disease, Alzheimer's disease, and various cancers and as anti-inflammatory agents. Despite once enjoying widespread use, MAOIs have dwindled in popularity due to side effects, food-drug interactions, and the introduction of other antidepressant drug classes such as tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). The recently published prescriber's guide for the use of MAOIs in treating depression has kindled a resurgence of their use in the clinical space. It is therefore timely to review key aspects of the four "classic" MAOIs: high-dose selegiline, isocarboxazid, phenelzine, and tranylcypromine. This review discusses their chemical synthesis, metabolism, pharmacology, adverse effects, and the history and importance of these drugs within the broader field of chemical neuroscience.

Repurposing antidepressants for anticancer drug discovery

Drug repurposing is an attractive strategy for identifying new indications for existing drugs. Three approved antidepressants have advanced into clinical trials for cancer therapy. In particular, further medicinal chemistry efforts with tranylcypromine (TCP) have led to the discovery of several TCP-based histone lysine specific demethylase 1 (LSD1) inhibitors that display therapeutic promise for treating cancer in the clinic. Thus repurposing antidepressants could be a promising strategy for cancer treatment. In this review, we illustrate the anticancer mechanisms of action of antidepressants and also discuss the challenges and future directions of repurposing antidepressants for anticancer drug discovery, to provide an overview of approved antidepressant cancer therapies.

Review and meta-analysis of add-on tranylcypromine with antipsychotic drugs for the treatment of schizophrenia with predominant negative symptoms: a restoration of evidence

BACKGROUND

Treatment using add-on antidepressants with antipsychotic drugs in negative symptoms of schizophrenia has been reviewed recently in comprehensive meta-analyses. Tranylcypromine (TCP), an irreversible monoamine oxidase (MAO)-A/B inhibitor applied in treatment resistant depression, was not included because of strict requirements for quality of study design. To get a clear picture of available evidence for this resource in the treatment of schizophrenia, we conducted a review and meta-analysis of add-on TCP in the treatment of predominant negative symptoms of schizophrenia (negative schizophrenia).

METHODS

Seven controlled studies of add-on TCP in schizophrenia with predominant negative symptoms were found in a search of multiple databases. A subset of four studies of the prospective and parallel comparison of add-on TCP with antipsychotic drugs vs. antipsychotic drug monotherapy and meeting minimum quality criteria formed the primary meta-analysis. The effect size was calculated as the natural logarithm of the odds ratio (logOR) of responders and non-responders.

RESULTS

In the primary meta-analysis, a pooled logOR = 1.092 with 95%CI 0.410-1.774 (I² = 43.4%, moderate heterogeneity) was calculated according to a fixed-effect model. Heterogeneity was reduced for three double-blind studies of add-on TCP with trifluoperazine (TFP) vs. TFP-monotherapy and resulted a pooled logOR = 0.916 with 95%CI 0.216-1.616 (I² negative, no heterogeneity). A significant logOR = 1.558 with 95%CI 0.340-2.776 was found for TCP/TFP compared to placebo in one study. In a meta-analysis of extrapyramidal adverse effects, studies were very heterogeneous and revealed no significant differences between treatments. The risk of exacerbation of positive symptoms with add-on TCP was found to be very low for a duration of treatment of 12-16 weeks. No cases of hypertensive crisis were reported. The main methodical limitations were insufficient description of randomization or matching of patients without randomization. The main clinical limitation is a gap of data for add-on TCP with second-generation antipsychotics.

CONCLUSION

New studies are needed for add-on TCP with antipsychotic drugs in schizophrenia with predominant negative symptoms. Trials of this treatment may be possible in rare and selected cases. The therapeutic effect of add-on TCP may be explained by a strong dopaminergic activity.

Tranylcypromine Isomers and Parkinson's Disease: New Aspects of an Old Drug

The tranylcypromine stereoisomers have been investigated in a series of comparative trials in Parkinson's disease and the results indicate that doses below 3 mg/day, of the (+)-isomer in particular, are effective as adjuvant antiparkinsonian therapy. Biochemical results, monitoring platelet monoamine oxidase (MAO) activity and plasma concentrations of drugs and phenylethylamine, an MAO substrate, showed such low doses of the (+)-isomer to inhibit MAO without inducing the hypertensive reaction sometimes observed at higher dosage. These findings, along with the observation of substantial pharmacokinetic differences between the two isomers are discussed, particularly in relation to reports on their efficacy in depressive illness.

[Tranylcypromine and khat: a potentially fatal combination]

It is well known that the use of tranylcypromine in combination with amphetamines may induce a potentially lethal hypertensive crisis. That such a complication may also occur when tranylcypromine is combined with khat, however, is less known. We describe the case of a young patient who received a low dose of tranylcypromine combined with a small amount of khat, subsequently developing a subarachnoid hemorrhage.

Tranylcypromine in mind (Part I): Review of pharmacology

It has been over 50 years since a review has focused exclusively on the monoamine oxidase (MAO) inhibitor tranylcypromine (TCP). A new review has therefore been conducted for TCP in two parts which are written to be read preferably in close conjunction: Part I - pharmacodynamics, pharmacokinetics, drug interactions, toxicology; and Part II - clinical studies with meta-analysis of controlled studies in depression, practice of TCP treatment, place in therapy. Pharmacological data of this review part I characterize TCP as an irreversible and nonselective MAO-A/B inhibitor at low therapeutic doses of 20mg/day with supplementary norepinephrine reuptake inhibition at higher doses of 40-60mg/day. Serotonin, norepinephrine, dopamine, and trace amines, such as the "endogenous amphetamine" phenylethylamine, are increased in brain, which leads to changes in neuroplasticity by e.g. increased neurotrophic growth factors and translates to reduced stress-induced hypersecretion of corticotropin releasing factor (CRF) and positive testing in animal studies of depression. TCP has a pharmacokinetic half-life (t_1/2) of only 2h which is considerably lower than for most other antidepressant drugs. However, a very long pharmacodynamic half-life of about one week is found because of the irreversible MAO inhibition. New studies show that, except for cytochrome P450 (CYP) 2A6, no other drug metabolizing CYP-enzymes are inhibited by TCP at therapeutic doses which defines a low potential of pharmacokinetic interactions in the direction from TCP to other drugs. Insufficient information is available, however, for plasma concentrations of TCP influenced by comedication. More quantitative data are also needed for TCP metabolites such as p-hydroxytranylcypromine and N-acetyltranylcypromine. Pharmacodynamic drug interactions comprise for instance severe serotonin toxicity (SST) with serotonergic drugs and hypertensive crisis with indirect sympathomimetics. Because of the risk of severe food interaction, TCP treatment remains beset with the need for a mandatory tyramine-restricted diet. Toxicity in overdose is similar to amitriptyline and imipramine according to the distance of therapeutic to toxic doses. In conclusion, TCP is characterized by an exceptional pharmacology which is different to most other antidepressant drugs, and a more special evaluation of clinical efficacy and safety may therefore be needed.

Glycaemic control by monoamine oxidase inhibition in a patient with type 1 diabetes

We present clinical, electroencephalographic and low-resolution electromagnetic tomography data that support combined treatment with insulin and a monoamine oxidase inhibitor in a patient with type 1 diabetes. We suggest that brain imaging data can identify a subgroup of patients who are likely to benefit from an insulin regimen and monoamine oxidase inhibition to improve glycaemic control, cardiovascular function, normalize the circadian rhythm and restore perception of glycaemic awareness.

Tranylcypromine, a lysine-specific demethylase 1 (LSD1) inhibitor, suppresses lesion growth and improves generalized hyperalgesia in mouse with induced endometriosis

BACKGROUND

Growing evidence indicates that endometriosis is an epigenetic disease. Encouragingly, histone deacetylases (HDACs) and DNA methyltransferases have been shown to be promising targets by numerous in vitro studies. However, only a few studies have shown promising effects of HDAC inhibition in preclinical studies in endometriosis. While lysine-specific demethylase 1 (LSD1) is recently found to be aberrantly expressed in endometriosis, and that the treatment of endometriotic stromal cells with tranylcypromine (TC), an LSD1 inhibitor, significantly reduced cellular proliferation, cell cycle progression, and invasiveness, the in vivo effect of TC treatment is currently lacking. This study sought to evaluate the effect of TC in a mouse model of endometriosis.

METHODS

Forty-seven female C57BL/6 mice were used in this experimentation. All mice, except those randomly selected to form Sham surgery (M) and specificity control (S) groups, received an endometriosis-inducing surgery. Group S was set up mainly to ensure that the reduced generalized hyperalgesia in mice treated with TC is not due to any possible analgesic effect of TC, but rather resulting from the treatment effect specific to endometriosis. Two weeks after the surgery, mice that received surgery were further divided randomly into 3 groups: 1) untreated group (U); 2) low-dose TC group (L); 3) high-dose TC group (H). Group S received the same treatment as in group H. Two weeks after treatment, all mice were sacrificed and their ectopic endometrial tissues were harvested and analyzed by immunohistochemistry analysis. Hotplate test was administrated to all mice before the induction, treatment and sacrifice. Lesion size, hotplate latency, immunoreactivity against markers of proliferation, angiogenesis, H3K4 methylation, and of epithelial-mesenchymal transition (EMT).

RESULTS

TC treatment significantly and substantially reduced the lesion size and improved generalized hyperalgesia in a dose-dependent fashion in mice with induced endometriosis. In addition, TC treatment resulted in reduced immunoreactivity to biomarkers of proliferation, angiogenesis, and H3K4 methylation, leading to arrested EMT and lesion growth.

CONCLUSION

In light of our previously reported reduced cellular proliferation, cell cycle progression and invasiveness resulting from the LSD1 inhibition in in vitro studies, our data strongly suggest that LSD1 is a promising therapeutic target for endometriosis.

TRIAL REGISTRATION

Not applicable.

The antidepressant trans-2-phenylcyclopropylamine protects mice from high-fat-diet-induced obesity

Mice treated with the antidepressant trans-2-phenylcyclopropylamine (2-PCPA) were protected against diet-induced-obesity, and adiposity was reversed in pre-established diet-induced obese mice. Contrary to a recent report that inhibition of lysine-specific demethylase-1 by 2-PCPA results in increased energy expenditure, long-term 2-PCPA treatment had no such effect but its protection against obesity was associated with increased spontaneous locomotor activity, Moreover, pair feeding to assure equal caloric intake in wild type mice as well as in genetic hyperphagic mice (ob/ob) also resulted in weight reduction in 2-PCPA treated mice that correlated with increased activity but no change in energy expenditure. Similarly, short-term intraperitoneal injections of 2-PCPA did not affect food intake but caused a substantial increase in locomotor activity in the light cycle that correlated with increased energy expenditure, whereas activity and energy expenditure were unchanged in the dark cycle. Lastly, 2-PCPA was also effective in reducing obesity in genetic UCP1 null mice. These data suggest that 2-PCPA can reduce obesity by decreasing food intake in the long term while increasing activity in the short-term. However, the protective and weight loss effects of 2-PCPA are independent of UCP1-regulated thermogenesis or basal energy expenditure.

[The treatment of psychotic depression in patients insufficiently responsive to conventional medication and electroconvulsive therapy; what are the options?]

Two patients with a psychotic depression showed insufficient response to pharmacotherapy and electroconvulsive therapy. The problem therefore was which alternative treatment options should be considered at this stage. On the bases of the available literature the most suitable options seemed to be clozapine, a monoamine oxidase inhibitor and lithium addition. Patient A responded well to clozapine and the condition of patient B improved during treatment with tranylcypromine, lithium and quetiapine.

Tranylcypromine vs. lamotrigine in the treatment of refractory bipolar depression: a failed but clinically useful study

OBJECTIVE

To compare the efficacy and tolerability of tranylcypromine vs. lamotrigine in bipolar depression not responding to conventional antidepressants.

METHOD

Bipolar depressed patients received open randomized treatment with tranylcypromine or lamotrigine as add-on to a mood stabilizer during 10 weeks. In a second treatment phase, non-responding patients could receive the opposite drug. Outcome criteria were response (measured with CGI-BP and IDS-C), switch into mania, and completion of the study.

RESULTS

Only 20 of 70 planned patients were randomized, due to problems with recruitment, and 19 patients received any medication. During the first treatment phase 5/8 patients (62.5%) responded to tranylcypromine without switch into mania, compared with 4/11 patients (36.4%) on lamotrigine with two switches (statistically not significant). Over both treatment phases, 8/10 patients (80%) receiving tranylcypromine completed the study vs. 5/13 (38.5%) on lamotrigine (likelihood 0.02).

CONCLUSION

There still appears to be a role for tranylcypromine in the treatment of refractory bipolar depression. Larger controlled studies are demanded.

Motor cortex excitability after vagus nerve stimulation in major depression

Recent data suggest that inhibitory pathways may be involved in the pathophysiology of depression and in the mode of action of some antidepressant interventions. The aim of the present study was to test whether vagus nerve stimulation (VNS) can affect motor cortex excitability. Measures of motor cortical excitability were probed by using single-pulse and paired-pulse transcranial magnetic stimulation at baseline, after 10 weeks of left VNS, and additionally, in an on-off paradigm in 10 patients with treatment-resistant unipolar depression. Ten weeks of VNS was associated with a selective and pronounced increase in intracortical inhibition, whereas no changes occurred in the on-off paradigm. These results suggest that VNS is capable of changing motor cortical excitability in patients with depression.

Tranylcypromine versus venlafaxine plus mirtazapine following three failed antidepressant medication trials for depression: a STAR*D report

OBJECTIVE

The purpose of this study was to compare the effectiveness and tolerability of tranylcypromine and combination treatment with extended-release venlafaxine and mirtazapine in patients with treatment-resistant major depression whose current depressive episode had not responded adequately to treatment in three prior prospective medication trials.

METHOD

Adult outpatients with nonpsychotic major depressive disorder who had not achieved remission or had withdrawn from treatment because of intolerance in three previous prospective medication trials were randomly assigned to receive open-label treatment with either tranylcypromine (N=58) or extended-release venlafaxine plus mirtazapine (N=51). The primary outcome measure was whether patients achieved remission, which was defined as a score < or =7 at exit on the 17-item Hamilton Depression Rating Scale (HAM-D). The HAM-D was administered by telephone by raters to whom treatment was masked.

RESULTS

Remission rates were not significantly different between the two treatment groups (6.9% for the tranylcypromine group and 13.7% for the venlafaxine plus mirtazapine group). The mean daily dose at exit for tranylcypromine was 36.9 mg (SD=18.5); for venlafaxine, 210.3 mg (SD=95.2); and for mirtazapine, 35.7 mg (SD=17.6). Tranylcypromine was associated with significantly less symptom reduction and greater attrition due to intolerance.

CONCLUSIONS

Remission rates were modest for both the tranylcypromine group and the extended-release venlafaxine plus mirtazapine group, and the rates were not statistically different between groups. The lower side effect burden, lack of dietary restrictions, and ease of use of venlafaxine and mirtazapine suggest that this combination may be preferred over tranylcypromine for patients with highly treatment-resistant depression who have not benefited adequately from several prior treatments.

Tranylcypromine: new perspectives on an "old" drug

The irreversible inhibitor of monoamine oxidase, tranylcypromine, is a potent antidepressant, but its use is limited to special indications due to side effects and dietary restrictions. The antidepressant action of tranylcypromine is not completely explainable by its effects on monoamine oxidase. Tranylcypromine also leads to an increase in brain trace amines, which are believed to play a key role in the pathophysiology of depression. It also affects other pathophysiological pathways associated with depression. Tranylcypromine treatment leads to an up-regulation of GABA(B)-receptors and modulates the phospholipid metabolism, which is essential for normal brain function. These findings implicate that the efficacy of tranylcypromine as an antidepressant may be due to its multiple actions within the human brain.

Transdermal selegiline: the new generation of monoamine oxidase inhibitors

The clinical use of monoamine oxidase inhibitors (MAOIs) has declined due to concerns about food and drug interactions and waning physician experience. Evidence indicates that MAOIs are effective in depressive disorders, in particular depression with atypical features. Efforts to address safety issues have led to the development of more selective and reversible MAOIs, such as moclobemide. Selegiline, a selective monoamine oxidase B inhibitor, has been approved for the adjunctive treatment of Parkinson's disease at low doses. At higher doses, oral selegiline is also effective in major depressive disorder (MDD) but loses its selectivity and has the potential for tyramine interactions. To overcome these problems, a transdermal formulation of selegiline, the selegiline transdermal system (STS), was developed with novel pharmacokinetic and pharmacodynamic properties. Compared with oral administration, transdermal selegiline leads to sustained plasma concentrations of the parent compound, increasing the amount of drug delivered to the brain and decreasing metabolite production. In addition, STS allows targeted inhibition of central nervous system monoamine A (MAO-A) and monoamine B isoenzymes with minimal effects on MAO-A in the gastrointestinal and hepatic systems, thereby reducing the risk of interactions with tyramine-rich foods (the "cheese-reaction"). Clinical trials have found 6 mg/24 hours of STS to be effective in MDD without the need for dietary restrictions. The efficacy and safety profile of STS supports its use in MDD. It is possible that STS may demonstrate benefit in MDD with atypical features or MDD resistant to other antidepressants. However, more research is needed. Clinicians should familiarize themselves with the properties and indications for the new generation of MAOIs.

Efficacy and tolerability of tranylcypromine versus phenelzine: a double-blind study in antidepressant-refractory depressed inpatients

BACKGROUND

The aim of this study was to examine whether phenelzine is a suitable alternative to tranylcypromine in antidepressant-resistant depression.

METHOD

A total of 77 severely depressed in-patients, meeting the DSM-IV criteria for major depressive disorder, who failed to respond to fixed plasma level treatment with either tricyclic antidepressants or fluvoxamine were withdrawn from psychotropic medication and included in a double-blind flexible-dose 5-week comparison of tranylcypromine and phenelzine.

RESULTS

Of the 77 patients, 67 (87%) completed the trial, of whom 35 (52%) responded. No significant differences in response between both drugs were observed. Seventeen (44%) of 39 patients responded to tranylcypromine and 18 (47%) of 38 to phenelzine (> or = 50% reduction in Hamilton Rating Scale for Depression [HAM-D] score). The mean reduction in HAM-D score was 10.4 +/- 8.3 for the tranylcypromine sample versus 8.3 +/- 8.4 for the phenelzine-treated patients. Only a few patients (10%) used concomitant psychotropic medication. A substantial number of patients experienced severe side effects, mainly dizziness, agitation, and insomnia; the incidence was the same in both samples (21%).

CONCLUSION

No difference in efficacy was observed between both monoamine oxidase inhibitors in a sample of patients with severe antidepressant-refractory depression. Phenelzine appears to be a suitable alternative to tranylcypromine.

Concomitant use of modafinil and tranylcypromine in a patient with narcolepsy: a case report

This is a case report of a patient with narcolepsy treated simultaneously with modafinil and tranylcypromine. The concurrent use of these two medications is normally contraindicated based on theoretical concerns. To our knowledge this is the first report of the combined use of these two medications in a patient for any reason. This combination of medications was particularly effective in the treatment of the patient's narcoleptic symptoms and was well tolerated, with no evidence of the potential cardiovascular side effects. Due to modafinil's lack of sympathomimetic activity and unique pharmacological profile, it may be well tolerated with monoamine oxidase inhibitor's (MAOI's) in humans with respect to hemodynamic parameters and concerns of hypertensive crisis. Further investigation would help clarify cardiovascular safety issues in using this combined therapy. We believe that with proper informed consent from the patient and careful monitoring, a combination of an MAOI and modafinil may be a viable treatment alternative in refractory cases of narcolepsy.

[Elderly patients, classical monoamine oxidase inhibitors and intercurrent somatic diseases]

Three patients, a woman aged 70, a man aged 74 and a woman aged 78 years, all using tranylcypromine, a monoamine oxidase inhibitor (MAOI), to prevent the recurrence of severe depressive disorders, developed an intercurrent somatic disease. On admission to a general hospital, the first patient was initially refused her MAOI. The second patient was twice refused anaesthesia and the depression recurred twice when the MAOI was tapered off in connection with his operation. Both recovered after being given tranylcypromine. The third patient received tramadol from her surgeon and read in the directions for use that this drug should not be combined with a MAOI. After discontinuation of the MAOI the depression recurred, her medical condition deteriorated and she died. MAOIs are often a treatment of last resort. Discontinuation of an effective treatment and hence compromising the patient's psychiatric status increases the risk of medical and psychiatric complications and therefore should be avoided. Interdisciplinary consultation is essential in such cases.

[Classical monoamine oxidase inhibitor: not registered for, but still a place in the treatment of depression]

In the Netherlands monoamine oxidase (MAO) inhibitors are not registered for the treatment of patients with depression. The classical, nonselective MAO inhibitors--phenelzine and tranylcypromine--are effective but their use is associated with interactions (with tyramine in food, sympathicomimetics and serotonine re-uptake inhibitors) and side-effects (hypertension, hypotension, headache, sleep disturbances and neuromuscular symptoms in particular). Therefore, the classical MAO inhibitors are indicated only in depressive disorders that are unresponsive to the first stages of treatment. Taking this selection into account, treatment should be long-term to avoid relapse.

Does depression influence symptom severity in irritable bowel syndrome? Case study of a patient with irritable bowel syndrome and bipolar disorder

OBJECTIVE

Irritable bowel syndrome (IBS) is frequently associated with mood disorder. However, it is typically difficult to distinguish between disturbed mood as a causal agent and disturbed mood as a consequence of the experience of IBS. This report considers the association between mood and symptom severity in a patient with diarrhea-predominant IBS and stable, rapid cycling bipolar disorder with a predominantly depressive course. Such a case provides an important opportunity to determine the direction of the relationship between mood and IBS symptom severity because the fluctuations of mood in bipolar disorder are assumed to be driven largely by biological, rather than psychosocial, processes.

METHODS

The study was carried out prospectively, with ratings of mood and IBS symptom severity made daily by the patient for a period of almost 12 months.

RESULTS

The patient experienced regular and substantial changes in mood as well as fluctuations in the level of IBS symptoms during the study period. Contrary to expectation, the correlation between mood and IBS symptom severity on the same day suggested that the patient experienced less severe IBS symptoms during periods of more severe depression. However, time series analysis revealed no significant association between these two processes when serial dependence within each series was controlled for.

CONCLUSIONS

The unusual co-occurrence of IBS with bipolar disorder provides direct evidence to indicate that depression does not necessarily lead to an increase in the reported severity of IBS, at least in the context of bipolar disorder, and may under certain circumstances actually be associated with a reduction in the severity of IBS symptoms. Factors that might moderate the relationship between depression and symptom severity are discussed.

Fatal interaction between tranylcypromine and imipramine

This case report describes a patient on tranylcypromine who erroneously received a single dose of imipramine and subsequently developed a fatal serotonin syndrome. Both the clinical features and the pathophysiology of the serotonin syndrome are discussed.

Effects of tranylcypromine on the sleep of patients with anergic bipolar depression

A significant proportion of patients with bipolar disorder are hypersomnolent. It is not clear if this affects response to treatment because few studies have systematically examined treatment effects on sleep in patients with bipolar depression. Reported herein are the results of what we believe to be the first study of the effects of the monoamine oxidase inhibitor tranylcypromine (average dose=37 mg/day) on the sleep of patients with bipolar depression.Twenty-three patients with anergic bipolar depression completed sleep studies before and after pharmacotherapy. Changes in polysomnographic variables were examined using paired t tests. The patients experienced a 40% reduction in rapid eye movement (REM) sleep time, as well as significant decreases in REM percentage,REM activity, number of REM periods, and REM intensity.REM latency was prolonged by nearly 3-fold. The decrease in REM sleep was accompanied by a modest (8%) reduction in total sleep time and increased "light" sleep. There was no change in sleep continuity indices or slow wave sleep. Correlational analyses suggested that antidepressant response was only weakly associated with changes in REM sleep. These findings indicate that tranylcypromine's effects on REM sleep greatly surpass effects on sleep architecture or sleep maintenance. Moreover, effective treatment of bipolar depression did not "normalize" the hypersomnolence associated with bipolar depression.

Bipolar depression: an underestimated treatment challenge

We sought to determine whether depressive and mixed/cycling episodes were as responsive to standardized pharmacotherapeutic interventions as were manic episodes in bipolar 1 patients. As part of the Maintenance Therapies in Bipolar Disorder (MH29618, E. Frank, PI) study, forty-two acutely ill bipolar 1 patients who had been randomly assigned to one of two preliminary phase non-pharmacologic treatment strategies (interpersonal and social rhythm therapy [IPSRT] or a standard medication clinic approach) were treated according to a standardized pharmacotherapeutic protocol. Symptom severity was measured weekly with the Hamilton Depression Rating Scale and the Bech-Rafaelsen Mania Scale in order to assess symptomatic remission. Survival analysis with the proportional hazards model was performed on time to remission. Manic patients were significantly more likely to achieve clinical remission than the depressed patients (100 vs. 59%) and did so significantly more rapidly. The difference in proportion remitting and time to remission between the depressed and mixed/cycling groups was not statistically significant. No significant effect for non-pharmacologic treatment assignment was found. These results point to the need to develop more effective treatments for bipolar depression. They also suggest that psychotherapy has a limited impact in the acute phase treatment of bipolar episodes.

Exercise, antidepressant medications, and enhanced brain derived neurotrophic factor expression

Physical activity and antidepressant treatment have each separately been of significant interest for the management of Alzheimer's disease (AD); particularly the behavioral problems associated with this dementing disorder. We have found that combined antidepressant treatment and physical activity have an additive, potentiating effect on BDNF mRNA expression within several areas of the rat hippocampus. During the 20-day experimental period, animals were treated daily with imipramine (15 mg/kg) or tranylcypromine (7.5 mg/kg) by intraperitoneal injection. Exercising rat groups were given access to running wheels for the duration of the experiment. BDNF mRNA levels were assessed in several cell groups of the hippocampus by in situ hybridization, using a [35S] labelled riboprobe complementary to the full-length BDNF sequence, and computer-assisted densitometry. The combination of physical activity and antidepressant treatment for the 20-day period led to a significant potentiation of full-length BDNF mRNA levels within the dentate gyrus and CA 1, CA 3, and CA 4 cellular fields, above the levels obtained with each intervention alone. These results provide impetus for the study of physical exercise as a potential enhancer of treatment response to antidepressants.

Evidence of a possible role of altered angiotensin function in the treatment, but not etiology, of depression

BACKGROUND

Angiotensin-converting enzyme inhibitors are reportedly effective in the treatment of depression; furthermore, antidepressants decrease angiotensin function. It appears therefore that reduced angiotensin function may be important in the treatment of depression. The aims of this study were to elucidate the actions of antidepressants on angiotensin receptors; to investigate the antidepressant potential of an angiotensin antagonist; and to study angiotensin receptors in depressed puerperal women.

METHODS

The effects of antidepressant drugs on angiotensin receptors and the relationship between mood and platelet receptors in puerperal women were investigated using radioligand binding. The antidepressant potential of the angiotensin antagonist losartan was assessed using the mouse forced swim test.

RESULTS

Desipramine, but neither fluoxetine nor tranylcypromine, displaced angiotensin from its receptor; however, there was no significant relationship between receptor number and depressed mood. In the forced swim test losartan was shown to possess antidepressant like activity.

CONCLUSIONS

These findings indicate that antidepressants differ in the mechanism by which they reduce angiotensin function, but the link between antidepressants and angiotensin is reiterated by the demonstration that losartan possesses antidepressant like activity. There is, however, no evidence of abnormal angiotensin receptors in women with depressed mood postpartum.

[Use of nonopiate agents for anesthesia in ENT patients at high surgical-anesthesiological risk]

Optimal methods of endotracheal anesthesia using non-opiate drugs of four classes (clofelin, transamine, contrykal, ketanes) have been fundamentally grounded developed and tried in extensive and traumatic operations for ENT malignant and vascular tumors as well as inflammation in patients of high anesthesiological operative risk. The drugs were used in 174 patients including 13 children. 87.9% of the patients had concomitant diseases: blood hypertension, coronary heart disease, chronic nonspecific pulmonary diseases, bronchial asthma, asthmatic bronchitis, diabetes mellitus, anemia. Adequate stable anesthesia was achieved in reduced dosage of conventional anesthesiological agents.

Inhibition of monoamine oxidase type A, but not type B, is an effective means of inducing anticonvulsant activity in the kindling model of epilepsy

The anticonvulsant activity of inhibitors of monoamine oxidase (MAO) was reported early after the development of irreversible MAO inhibitors such as tranylcypromine, but was never clinically used because of the adverse effects of these compounds. The more recently developed reversible MAO inhibitors with selectivity for either the MAO-A or MAO-B isoenzyme forms have not been studied extensively in animal models of epilepsy, so it is not known which type of MAO inhibitor is particularly effective in this respect. We compared the following drugs in the kindling model of epilepsy: 1) L-deprenyl (selegiline), i.e., an irreversible inhibitor of MAO-B, which, however, also inhibits MAO-A at higher doses, 2) the novel reversible MAO-B inhibitor LU 53439 (3,4-dimethyl-7-(2-isopropyl-1,3, 4-thiadiazol-5-yl)-methoxy-coumarin), which is much more selective for MAO-B than L-deprenyl, 3) the novel reversible and highly selective MAO-A inhibitor LU 43839 (esuprone; 7-hydroxy-3, 4-dimethylcoumarin ethanesulfonate), and 4) the irreversible nonselective MAO inhibitor tranylcypromine. Esuprone proved to be an effective anticonvulsant in the kindling model with a similar potency as L-deprenyl. In contrast to esuprone and L-deprenyl, the selective MAO-B inhibitor LU 53439 was not effective in the kindling model; this substantiates the previous notion that the anticonvulsant activity of L-deprenyl is not related to MAO-B inhibition, but to other effects of this drug, such as inhibition of MAO-A. Drugs inhibiting both MAO-A and MAO-B to a similar extent (tranylcypromine) or combinations of selective MAO-A and MAO-B inhibitors (esuprone plus LU 53439) had no advantage over MAO-A inhibition alone, but were less well tolerated. The data thus suggest that selective MAO-A inhibitors such as esuprone may be an interesting new approach for the treatment of epilepsy.

Experience with tranylcypromine in early Parkinson's disease

A leading hypothesis of the pathogenesis of neuronal degeneration of the substantia nigra dopamine-containing cells in Parkinson's disease (PD) is excessive oxidative stress. In part, this oxidative stress is the result of the oxidation of dopamine by the action of monoamine oxidases (MAO) A and B to generate hydrogen peroxide and subsequent oxygen free radicals. Because of this hypothesis we have treated patients with early PD, not yet requiring any symptomatic treatment, with tranylcypromine, a drug that inhibits both MAO's. These patients were required to observe a tyramine-restricted diet. Thirty-seven patients on tranylcypromine have been followed by us for up to 33 months. Four patients discontinued the drug because of pending surgery. Of the remaining 33, six had adverse effects that lead to discontinuation of the drug, mainly impotency in men. Another common adverse effect encountered was insomnia, but this problem was not a cause of stopping the drug. Depression lifted in all five patients who had this problem at the time tranylcypromine was initiated. Only two patients have so far required treatment with levodopa or a dopamine agonist, and this need occurred within the first 6 months of treatment. The evaluation of all 37 patients revealed that parkinsonian symptoms improved slightly on introduction of tranylcypromine as measured by the United Parkinson's Disease Rating Scale, the Hoehn & Yahr Staging Scale, and the Schwab & England Activities of Daily Living Scale. Follow-up evaluations for a minimum of 6 months between the first post-tranylcypromine visit and the most recent visit revealed only slight worsening of parkinsonian signs and symptoms, with a mean interval of almost 1.5 years. A longer period of follow-up is needed to determine how long the severity of PD will remain mild in this group of patients.

Serotonin syndrome due to venlafaxine and maintenance tranylcypromine therapy

A number of novel serotonergic antidepressants have been introduced to clinical practice over the last decade. These medications are felt to be safe alternatives to the traditional tricyclic antidepressants and monoamine oxidase inhibitors, particularly in the overdose setting. Serious adverse reactions and drug interactions have been appreciated and fatalities have been reported. We describe the development of the serotonin syndrome in a 60 year old female on chronic tranylcypromine treatment following the inadvertent ingestion of a single dose of venlafaxine. Manifestations included and altered mental status that progressed to hyperthermia and coma. She recovered quickly and without complications. Health care providers and poison specialists need to be aware that this potentially serious syndrome can be precipitated by a single dose of a serotonin reuptake inhibitor in patients being treated with a monoamine oxidase inhibitor.