Common side effects associated with monoamine oxidase inhibitors

A comprehensive overview of post-stroke depression treatment options

Nearly one-third of all stroke patients develop depression at any time after a stroke, and its presence is associated with unfavorable outcomes. This narrative review aims to provide a synopsis of possible pharmacological and non-pharmacological treatment modalities for post-stroke depression (PSD). Several studies have demonstrated the efficacy and safety of selective serotonin reuptake inhibitors in treating the symptoms of this clinical condition. The treatment of PSD has been recently enhanced by innovative approaches, such as cognitive-behavioral therapy, virtual reality, telehealth, repetitive transcranial magnetic stimulation, and non-conventional therapies, which might improve depression treatment in stroke survivors. Future high-quality randomized controlled trials are necessary to confirm this hypothesis.

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.

Clinical Manifestations of Subjective Sleep Disorders in Chinese Patients with Parkinson's Disease and Their Relationship with Dopaminergic Drugs

INTRODUCTION

Sleep disorders are common in Parkinson's disease (PD) and significantly impact quality of life. Herein, we surveyed the incidence and severity of sleep disorders in Chinese PD patients and observed their relationship with dopaminergic drugs.

METHODS

We collected the demographic and disease information of 232 PD patients. The incidence and severity of sleep disorders were surveyed with the Parkinson's disease sleep scale (PDSS) Chinese version. Data on dopaminergic drug intake were collected and converted to levodopa equivalent doses (LED).

RESULTS

The average total score of PDSS in 232 patients was 119.3 ± 19.7. There was a significant difference in PDSS scores between groups classified by the Hoehn-Yahr (H&Y) stage, but not between the groups classified by the type of dopaminergic drugs. Stepwise regression analysis revealed that the LED of dopaminergic drugs taken before bedtime (p < 0.00), LED of dopaminergic drugs taken over a 24-h period (p < 0.00), and scores of the Hamilton Rating Scale for Depression (HAMD) (p = 0.01) were determinants of PDSS.

CONCLUSION

Sleep disorders in PD patients may be multifactorial. High dosage of dopaminergic drugs taken prior to sleep, daily total high dosage of dopaminergic drugs, and depression exert negative effects on subjective sleep. The timing and dosage of dopaminergic drugs taken before bedtime should be considered in PD management.

Pathophysiology and Current Drug Treatments for Post-Stroke Depression: A Review

Post-stroke depression (PSD) is a biopsychosocial disorder that affects individuals who have suffered a stroke at any point. PSD has a 20 to 60 percent reported prevalence among stroke survivors. Its effects are usually adverse, can lead to disability, and may increase mortality if not managed or treated early. PSD is linked to several other medical conditions, including anxiety, hyper-locomotor activity, and poor functional recovery. Despite significant awareness of its adverse impacts, understanding the pathogenesis of PSD has proved challenging. The exact pathophysiology of PSD is unknown, yet its complexity has been definitively shown, involving mechanisms such as dysfunction of monoamine, the glutamatergic systems, the gut-brain axis, and neuroinflammation. The current effectiveness of PSD treatment is about 30-40 percent of all cases. In this review, we examined different pathophysiological mechanisms and current pharmacological and non-pharmacological approaches for the treatment of PSD.

The prescriber's guide to classic MAO inhibitors (phenelzine, tranylcypromine, isocarboxazid) for treatment-resistant depression

This article is a clinical guide which discusses the "state-of-the-art" usage of the classic monoamine oxidase inhibitor (MAOI) antidepressants (phenelzine, tranylcypromine, and isocarboxazid) in modern psychiatric practice. The guide is for all clinicians, including those who may not be experienced MAOI prescribers. It discusses indications, drug-drug interactions, side-effect management, and the safety of various augmentation strategies. There is a clear and broad consensus (more than 70 international expert endorsers), based on 6 decades of experience, for the recommendations herein exposited. They are based on empirical evidence and expert opinion-this guide is presented as a new specialist-consensus standard. The guide provides practical clinical advice, and is the basis for the rational use of these drugs, particularly because it improves and updates knowledge, and corrects the various misconceptions that have hitherto been prominent in the literature, partly due to insufficient knowledge of pharmacology. The guide suggests that MAOIs should always be considered in cases of treatment-resistant depression (including those melancholic in nature), and prior to electroconvulsive therapy-while taking into account of patient preference. In selected cases, they may be considered earlier in the treatment algorithm than has previously been customary, and should not be regarded as drugs of last resort; they may prove decisively effective when many other treatments have failed. The guide clarifies key points on the concomitant use of incorrectly proscribed drugs such as methylphenidate and some tricyclic antidepressants. It also illustrates the straightforward "bridging" methods that may be used to transition simply and safely from other antidepressants to MAOIs.

Search for safer and potent natural inhibitors of Parkinson's disease

After Alzheimer's disease, Parkinson's disease (PD) has taken second place in becoming one of the most commonly occurring neurological diseases being responsible for a number of disabling motor symptoms ranging from bradykinesia, akinesia, tremors to rigidity, that mostly targets the elderly population and severely disrupts their quality of life. The true underlying pathology of PD yet remains a mystery, however, recent advances in the field have pointed towards the production of α-synuclein aggregates, oxidative stress, and an imbalance between levels of acetylcholine and dopamine neurotransmitters in the brain that have been shown to result in loss of coordinated movement. Current treatments of PD include the gold standard dopamine precursor L-dopa, dopamine agonists pergolide and bromocriptine, catechol-o-methyl transferases inhibitors, entacapone and tolcapone and monoamine oxidase inhibitors such as Selegine and Rasagiline amongst several other drugs. While these drugs are successful in treating motor symptoms of the disease, they do so with a plethora of side effects that are especially debilitating to the elderly. In the recent years, a considerable amount of attention has been shifted towards phytocompounds such as flavonoids and green tea catechins due to promising experimental results. In this review, we have compiled phytocompounds that have shown potent activity against some of the most important targets for antiparkinsonian therapy. These compounds have exhibited activities that transcend the limits of simply attenuating mitochondrial oxidative stress and have opened doors to the discovery of novel lead compounds for newer, efficacious antiparkinsonian therapies with wider therapeutic windows.

Antidepressant-induced sexual dysfunction

Sexual dysfunction is a frequent, potentially distressing, adverse effect of antidepressants and a leading cause of medication non-adherence. Sexual function should be actively assessed at baseline, at regular intervals during treatment, and after treatment cessation. Trials comparing the risk of sexual dysfunction with individual antidepressants are inadequate, but it is reasonable to conclude that the risk is greatest with selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs), less with tricyclic antidepressants (except clomipramine) and mirtazapine, and least with moclobemide, agomelatine, reboxetine and bupropion. Management of antidepressant-induced sexual dysfunction requires an individualised approach (eg, considering other causes, dose reduction, addition of medication to treat the adverse effect, switching to a different antidepressant). Post-SSRI sexual dysfunction has been recently identified as a potential, although rare, adverse effect of SSRIs and SNRIs. Consider the possibility of post-SSRI sexual dysfunction in patients in whom sexual dysfunction was absent before starting antidepressants but develops during or soon after antidepressant treatment and still persists after remission from depression and discontinuation of the drug.

OnabotulinumtoxinA for the treatment of major depressive disorder: a phase 2 randomized, double-blind, placebo-controlled trial in adult females

This 24-week double-blind placebo-controlled multicenter randomized phase 2 trial evaluated efficacy and safety of onabotulinumtoxinA (onabotA; BOTOX) vs. placebo for major depressive disorder (MDD) [NCT02116361]. Primary endpoint was the change in Montgomery-Åsberg Depression Rating Scale (MADRS); secondary endpoints were Clinical Global Impressions-Severity and 17-item Hamilton Depression Rating Scale at week 6. A total of 255 adult females were treated. OnabotA 30 U approached significance compared to placebo on MADRS (mixed-effect model repeated measures least-squares mean difference: -3.7; P = 0.053) and reached significance [least-squares mean differences: -3.6 to -4.2; P < 0.05 (two-sided)] at weeks 3 and 9. Secondary endpoints were also significant at several time points. At week 6, onabotA 50 U did not separate from placebo in any parameters. OnabotA was generally well-tolerated: the only treatment-emergent adverse events reported in ≥5% in either onabotA group, and more than matching placebo were headache, upper respiratory infection, and eyelid ptosis. OnabotA 30 U, administered in a standardized injection pattern in a single session, had a consistent efficacy signal across multiple depression symptom scales for 12 or more weeks. OnabotA 30 U/placebo MADRS differences of (observed ANCOVA) ≥4.0 points (up to week 15) and ≥2.0 points (weeks 18-24) agree with the 2-point change threshold considered clinically relevant in MDD. OnabotA is a local therapy and is not commonly associated with systemic effects of conventional antidepressants and may represent a novel treatment option for MDD.

Tranylcypromine Causes Neurotoxicity and Represses BHC110/LSD1 in Human-Induced Pluripotent Stem Cell-Derived Cerebral Organoids Model

Recent breakthroughs in human pluripotent stem cell-derived cerebral organoids provide a valuable platform for investigating the human brain after different drugs treatments and for understanding the complex genetic background to human pathology. Here, we identified tranylcypromine, which is used to treat refractory depression, caused human-induced pluripotent stem cell-derived brain organoids neurotoxicity, leading to decreased proliferation activity and apoptosis induction. Moreover, tranylcypromine treatment affects neurons and astrocytes, which impairs cell density and arrangement. Finally, staining of histone demethylation-related genes revealed that tranylcypromine suppresses the transcriptional activity of BHC110/LSD1-targeted genes and increases the expression of histone di-methylated K4. These results show that human brain organoids can be applied as an in vitro model for CNS drug screening to evaluate structural, cellular, and molecular changes in the normal brains or brains of patients with neuropsychiatric disorders after drug treatments.

Quetiapine for Insomnia Associated with Refractory Depression Exacerbated by Phenelzine

Objective:

To report the successful treatment of phenelzine-associated insomnia with low-dose quetiapine in a patient with refractory depression.

Case Summary:

A 42-year-old white man with severe major depression unresponsive to selective serotonin-reuptake inhibitors, bupropion, and tricyclic antidepressants improved following treatment with the monoamine oxidase inhibitor (MAOI) phenelzine. Insomnia, present to a moderate degree prior to antidepressant therapy, worsened markedly following phenelzine treatment and failed to respond to diphenhydramine, temazepam, triazolam, clonazepam, Zolpidem, or trazodone given at high therapeutic doses. Sleep disturbance resolved with low-dose (50 mg) adjunctive quetiapine, with no adverse effects.

Discussion:

Major depression refractory to standard therapy is a common and serious condition. Some cases respond to MAOIs; however, orthostatic hypotension and insomnia frequently occur. Potentially serious MAOI interactions with psychotropic drugs have raised concerns about combining these agents. In this case, a failure of a number of other medications known to treat MAOI-associated insomnia safely prompted a trial of quetiapine. Despite the possibility that enhanced serotonergic activity might have resulted in serotonin syndrome, no adverse interactions between phenelzine and quetiapine were noted. The use of low-dose, once-daily quetiapine, along with its unique binding properties, may account for its increased safety in combination with phenelzine.

Conclusions:

This case illustrates that low-dose quetiapine may be an alternative treatment for phenelzine-associated insomnia. Further case reports are needed to establish the safety and effectiveness of combining these agents.

Treatment of depression with onabotulinumtoxinA: a randomized, double-blind, placebo controlled trial

Converging lines of evidence suggest a role for facial expressions in the pathophysiology and treatment of mood disorders. To determine the antidepressant effect of onabotulinumtoxinA (OBA) treatment of corrugator and procerus muscles in people with major depressive disorder, we conducted a double blind, randomized, placebo-controlled trial. In an outpatient clinical research center, eighty-five subjects with DSM-IV major depression were randomized to receive either OBA (29 units for females and 40 units for males) or saline injections into corrugator and procerus frown muscles (74 subjects were entered into the analysis). Subjects were rated at screening, and 3 and 6 weeks after OBA treatment. The primary outcome measure was the response rate, as defined by ≥ 50% decrease in score on the Montgomery-Asberg Depression Rating Scale (MADRS). Response rates at 6 weeks from the date of injection were 52% and 15% in the OBA and placebo groups, respectively (Chi-Square (1) = 11.2, p < 0.001, Fisher p < 0.001). The secondary outcome measure of remission rate (MADRS score of 10 or less) was 27% with OBA and 7% with placebo (Chi-square (1) = 5.1, p < 0.02, Fisher p < 0.03). Six weeks after a single treatment, MADRS scores of subjects were reduced on average by 47% in those given OBA, and by 21% in those given placebo (Mann-Whitney U, p < 0.0005). In conclusion, a single treatment with OBA to the corrugator and procerus muscles appears to induce a significant and sustained antidepressant effect in patients with major depression.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01556971.

A review of vilazodone, serotonin, and major depressive disorder

Objective: To review the mechanism of selective serotonin reuptake inhibitor (SSRI)–mediated serotonergic neurotransmission, focusing on serotonin 1A (5-HT_1A) autoreceptors, which are proposed to be involved in delaying therapeutic efficacy. Vilazodone was specifically designed to function both as an SSRI and a partial agonist at 5-HT_1A receptors. This combined mechanism is proposed to decrease time to efficacy, minimize sexual side effects, and provide concomitant anxiolytic properties.

Data Sources: A PubMed search of all English-language articles from January 1990 to January 2013 was conducted using the search terms depression and 5-HT_1A, depression and buspirone, depression and pindolol, and vilazodone.

Study Selection: We found 47 articles and abstracts that were selected for inclusion on the basis of information about the pharmacology of 5-HT_1A receptors and the clinical data on pindolol, buspirone, and vilazodone in depression.

Data Extraction: This review summarizes current literature involving antidepressant activity, the role of 5-HT_1A autoreceptors, and clinical trials involving serotonin reuptake inhibition in conjunction with 5-HT_1A agonists and partial agonists, with a focus on vilazodone.

Results:Vilazodone has demonstrated efficacy in 2 large, randomized, double-blind, placebo-controlled trials in major depressive disorder. Results suggest that vilazodone has a low incidence of sexual side effects and is effective in patients with high levels of anxiety. A pooled analysis shows evidence of significant symptom reduction after only 1 week of therapy.

Conclusions: If future studies corroborate the clinical benefits attributed to its mechanism of action, vilazodone may show potential advantages in terms of onset of action, sexual side effects, and anxiolytic activity in patients with major depressive disorder.

MAO-inhibitors in Parkinson's Disease

Monoamine oxidase inhibitors (MAO-I) belong to the earliest drugs tried in Parkinson's disease (PD). They have been used with or without levodopa (L-DOPA). Non-selective MAO-I due to their side-effect/adverse reaction profile, like tranylcypromine have limited use in the treatment of depression in PD, while selective, reversible MAO-A inhibitors are recommended due to their easier clinical handling. For the treatment of akinesia and motor fluctuations selective irreversible MAO-B inhibitors selegiline and rasagiline are recommended. They are safe and well tolerated at the recommended daily doses. Their main differences are related to (1) metabolism, (2) interaction with CYP-enzymes and (3) quantitative properties at the molecular biological/genetic level. Rasagiline is more potent in clinical practise and has a hypothesis driven more favourable side effect/adverse reaction profile due to its metabolism to aminoindan. Both selegiline and rasagiline have a neuroprotective and neurorestaurative potential. A head-to head clinical trial would be of utmost interest from both the clinical outcome and a hypothesis-driven point of view. Selegiline is available as tablet and melting tablet for PD and as transdermal selegiline for depression, while rasagiline is marketed as tablet for PD. In general, the clinical use of MAO-I nowadays is underestimated. There should be more efforts to evaluate their clinical potency as antidepressants and antidementive drugs in addition to the final proof of their disease-modifying potential. In line with this are recent innovative developments of MAO-I plus inhibition of acetylcholine esterase for Alzheimer's disease as well as combined MAO-I and iron chelation for PD.

Is unrecognized bipolar disorder a frequent contributor to apparent treatment resistant depression?

BACKGROUND

There is widespread clinical belief that unrecognized bipolar disorder (BD) is a frequent contributor to apparent treatment resistant depression (TRD). This review attempts to assess the degree to which prevailing empirical data supports that view.

METHODS

All English-language articles published between January 1998 and January 2008 that focused on adults with major depressive disorder (MDD) and BD bearing on the question "Is unrecognized BD a frequent contributor to apparent TRD in patients initially diagnosed with MDD?" were reviewed.

RESULTS

196 articles were reviewed; the preponderance of the data suggested: 1) TRD populations demonstrate high rates of hidden bipolar disorder, 2) there is not sufficient evidence to unequivocally support or reject the hypothesis that patients who relapse despite continued antidepressant treatment are likely to have bipolar spectrum disorder, 3) patients initially diagnosed with MDD do not demonstrate high rates of switching to mania or hypomania when treated with antidepressants and 4) in patients diagnosed with BD, antidepressants are not robustly effective and are poorly tolerated.

LIMITATIONS

The main limitation of this review is that none of the individual studies were designed to test our primary hypothesis.

CONCLUSIONS

This review provides at least moderate support to the hypothesis that BD is a contributor to apparent TRD. Thus, clinicians treating MDD are urged to search for "soft" signs of bipolarity and to be prepared to alter diagnosis and treatment strategies accordingly.

Bilateral ankle oedema in a patient taking escitalopram

Escitalopram (ESC) is the S-isomer of the racemic compound citalopram, and has been shown to be an efficacious treatment for major depressive disorder. Several studies or case reports are available describing its side effects, none of which however refer to its potential to induce ankle oedema. We report the case of a 69-year-old female depressed patient who, after approximately 1 month of therapy with ESC, progressively titrated up to 30 mg/day, developed a bilateral ankle oedema, which resolved completely within the first week following its discontinuation.

Antidepressant phenelzine alters differentiation of cultured human and mouse preadipocytes

Change in body weight is a frequent side effect of antidepressants and is considered to be mediated by central effects on food intake and energy expenditure. The antidepressant phenelzine (Nardil) potently inhibits both monoamine oxidase and semicarbazide-sensitive amine oxidase activities, two enzymes that are highly expressed in adipose tissue, raising the possibility that it could directly alter adipocyte biology. Treatment with this compound is rather associated with weight gain. The aim of this work was to examine the effects of phenelzine on differentiation and metabolism of cultured human and mouse preadipocytes and to characterize the mechanisms involved in these effects. In all preadipocyte models, phenelzine induced a time- and dose-dependent reduction in differentiation and triglyceride accumulation. Modulation of lipolysis or glucose transport was not involved in phenelzine action. This effect was supported by the reduced expression in the key adipogenic transcription factors peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and CCAAT/enhancer binding protein-alpha, which was observed only at the highest drug concentrations (30-100 microM). The PPAR-gamma agonists thiazolidinediones did not reverse phenelzine effects. By contrast, the reduction in both cell triglycerides and sterol regulatory element-binding protein-1c (SREBP-1c) was detectable at lower phenelzine concentrations (1-10 microM). Phenelzine effect on triglyceride content was prevented by providing free fatty acids to the cells and was partially reversed by overexpression of a dominant-positive form of SREBP-1c, showing the privileged targeting of the lipogenic pathway. When considered together, these findings demonstrate that an antidepressant directly and potently inhibits adipocyte lipid storage and differentiation, which could contribute to psychotropic drug side effects on energy homeostasis.

Associations of a regulatory polymorphism of monoamine oxidase-A gene promoter (MAOA-uVNTR) with symptoms of depression and sleep quality

OBJECTIVE

To examine the relationships among the variable number of tandem repeats in the monoamine oxidase-A linked polymorphic region allelic variation (MAOA-uVNTR) and the symptoms of depression and sleep quality. The monoamine oxidase-A (MAOA) gene, which plays a vital role in degradation of neurotransmitters such as serotonin, norepinephrine, and dopamine, contains a polymorphism in its promoter region (MAOA-uVNTR) that affects transcriptional efficiency. MAOA-uVNTR genotype has been associated with both psychological and physical measures.

METHODS

The sample consisted of 74 males enrolled in a case/control study of caregivers for relatives with dementia. Age- and race-adjusted linear regression models were used to examine the association between low versus high MAOA-uVNTR activity alleles, symptoms of depression (Center for Epidemiological Studies of Depression), and sleep quality ratings (Pittsburgh Sleep Quality Index).

RESULTS

MAOA-uVNTR alleles associated with less transcriptional activity were related to increased symptoms of depression (p < .04; Cohen's d = 0.52) and poorer sleep quality (p < .04; Cohen's d = 0.31).

CONCLUSIONS

Individuals with less active MAOA-uVNTR alleles may be at increased risk for depressive symptoms and poor sleep.

Tocotrienols reverse IKAP and monoamine oxidase deficiencies in familial dysautonomia

Familial dysautonomia (FD), a recessive neurodegenerative disease, is caused by mutations in the IKBKAP gene that result in the production of nonfunctional IKAP protein. Manifestations of FD include autonomic crises characterized by hypertension, tachycardia, diaphoresis, and vomiting. Elevated plasma levels of norepinephrine (NE) and dopamine observed during autonomic crises and an exaggerated hypertensive response to low doses of NE prompted an examination of monoamine oxidase (MAO) levels, key isoenzymes responsible for degrading biogenic and dietary monoamines, in individuals with FD. Fetal tissue homozygous for the common FD-causing mutation and peripheral blood cells of individuals with FD have reduced MAO A mRNA levels. FD-derived cells, stimulated with tocotrienols or EGCG to produce increased levels of functional IKAP, express increased amounts of MAO A mRNA transcript and protein. Administration of tocotrienol to individuals with FD results in increased expression of both functional IKAP and MAO A transcripts in their peripheral blood cells. These findings provide new insight into the pathophysiology of FD and demonstrate the value of therapeutic approaches designed to elevate cellular levels of functional IKAP and MAO A.

A review of antidepressant-induced hypomania in major depression: suggestions for DSM-V

OBJECTIVES

To determine if the classification of 'antidepressant-induced hypomania' in DSM-IV is supported by available data.

METHODS

We reviewed the available scientific literature to examine the incidence of mania and hypomania in non-bipolar patients who were treated with antidepressants.

RESULTS

Eighty-nine per cent of studies of antidepressants in major depressive disorder patients reported no cases of treatment-induced hypomania. No instances of treatment-induced hypomania were reported in three large studies of patients with chronic forms of depression.

CONCLUSIONS

The rate of antidepressant-induced hypomania in major depressive disorder is within the rate of misdiagnosis of bipolar depression as unipolar. Depressed patients who experience antidepressant-associated hypomania are truly bipolar.

Disruption of the activity-rest cycle by MAOI treatment: dependence on light and a secondary visual pathway to the circadian pacemaker

The disruptive effects on the activity-rest cycle of the monoamine oxidase inhibitor (MAOI) clorgyline and of continuous light were examined in Syrian hamsters. When administered in dim and moderate light intensities, clorgyline delayed the daily onset of wheel-running. When administered in bright light, it dissociated the circadian rhythm of wheel-running. This dissociation was prevented by lesions of the intergeniculate leaflet of the ventral lateral geniculate nucleus. Constant darkness restored the circadian rhythm of wheel-running in hamsters with disrupted circadian rhythms. The phase of the restored rhythm of wheel-running was shifted 6-12 h later than the phase of wheel-running prior to dissociation. Our results suggest that MAOI treatment weakens the coupling between oscillators that comprise the circadian pacemaker, and augments the disruptive effects of continuous light acting via the intergeniculate leaflet region of the ventral lateral geniculate nucleus. These effects on the circadian pacemaker may be responsible for disruptions of the sleep-wake cycle that occur as side effects when MAOIs are used clinically to treat depression and might play a role in the induction of mania and rapid cycling by antidepressants.

Circadian rhythms and the pharmacology of affective illness

The chronic effects of antidepressant drugs (ADs) on circadian rhythms of behavior, physiology and endocrinology are reviewed. The timekeeping properties of several classes of ADs, including tricyclic antidepressants, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, serotonin agonists and antagonists, benzodiazepines, and melatonin are reviewed. Pharmacological effects on the circadian amplitude and phase, as well as effects on day-night measurements of motor activity, sleep-wake, body temperature (Tb), 3-methoxy-4-hydroxyphenylglycol, cortisol, thyroid hormone, prolactin, growth hormone and melatonin are examined. ADs often lower nocturnal Tb and affect the homeostatic regulation of sleep. ADs often advance the timing and decrease the amount of slow wave sleep, reduce rapid eye movement sleep and increase or decrease arousal. Together, AD effects on nocturnal Tb and sleep may be related to their therapeutic properties. ADs sometimes delay nocturnal cortisol timing and increase nocturnal melatonin, thyroid hormone and prolactin levels; these effects often vary with diagnosis, and clinical state. The effects of ADs on the coupling of the central circadian pacemaker to photic and nonphotic zeitgebers are discussed.

Spontaneous hypertensive reactions with monoamine oxidase inhibitors

Despite long-standing concerns over hypertensive reactions, monoamine oxidase inhibitors (MAOIs) have grown in popularity and are now used in a variety of psychiatric disorders. The risk of hypertensive episodes is less than 1%. This is most likely the result of careful dietary instructions and prudent prescribing of concomitant medications. The possibility exists of spontaneous or unprovoked hypertensive crises in patients receiving MAOIs. In this report, we review the literature on spontaneous hypertensive episodes and present a case report. There has been a total of 11 cases described in six separate reports. We discuss the possible mechanism, risk factors, treatment, and safety of rechallenging the patients with the MAOI. Further research is needed to clarify this reaction. For now, it remains a rare but worrisome phenomenon. It should stand as an additional source of concern for clinicians who are already well aware of the risk of hypertensive episodes in patients receiving MAOIs.

Drug-induced male sexual dysfunction. An update

Impotence, defined as the consistent inability to maintain an erect penis of sufficient rigidity for sexual intercourse, has been estimated to affect 10 million American men. An age dependence has been shown to exist, with 25% of men over age 65 affected. A large body of clinical experience and published reports in the literature link many commonly prescribed drugs with sexual dysfunction. Drugs can affect sexual function at a variety of points such as inhibition of ejaculation or sedation/depression leading to reduced libido. Antihypertensive drugs have been most commonly associated with impotence. There have been reports of sexual dysfunction with almost all classes of antipsychotics, but little clinical investigation has been performed. Other drugs associated with sexual dysfunction include digoxin, clofibrate, cimetidine and various hormonal agents and antineoplastics. An important first step in approaching all impotent patients is the taking of a detailed medical, surgical, sexual and drug/substance abuse history. The least invasive form of therapy should be employed. Recent studies have shown intracavernous injections of alprostadil (prostaglandin E1) to be safe and effective for long term use. Vacuum constriction devices may also be of help. Better and more durable prostheses are now available should other treatment be unsuccessful.