Monoamine oxidase inhibitors: prescription and patient management

Acrolein as a novel therapeutic target for motor and sensory deficits in spinal cord injury

IN THE HOURS TO WEEKS FOLLOWING TRAUMATIC SPINAL CORD INJURIES (SCI), BIOCHEMICAL PROCESSES ARE INITIATED THAT FURTHER DAMAGE THE TISSUE WITHIN AND SURROUNDING THE INITIAL INJURY SITE: a process termed secondary injury. Acrolein, a highly reactive unsaturated aldehyde, has been shown to play a major role in the secondary injury by contributing significantly to both motor and sensory deficits. In particular, efforts have been made to elucidate the mechanisms of acrolein-mediated damage at the cellular level and the resulting paralysis and neuropathic pain. In this review, we will highlight the recent developments in the understanding of the mechanisms of acrolein in motor and sensory dysfunction in animal models of SCI. We will also discuss the therapeutic benefits of using acrolein scavengers to attenuate acrolein-mediated neuronal damage following SCI.

Acrolein-mediated injury in nervous system trauma and diseases

Acrolein, an α,β-unsaturated aldehyde, is a ubiquitous pollutant that is also produced endogenously through lipid peroxidation. This compound is hundreds of times more reactive than other aldehydes such as 4-hydroxynonenal, is produced at much higher concentrations, and persists in solution for much longer than better known free radicals. It has been implicated in disease states known to involve chronic oxidative stress, particularly spinal cord injury and multiple sclerosis. Acrolein may overwhelm the anti-oxidative systems of any cell by depleting glutathione reserves, preventing glutathione regeneration, and inactivating protective enzymes. On the cellular level, acrolein exposure can cause membrane damage, mitochondrial dysfunction, and myelin disruption. Such pathologies can be exacerbated by increased concentrations or duration of exposure, and can occur in normal tissue incubated with injured spinal cord, showing that acrolein can act as a diffusive agent, spreading secondary injury. Several chemical species are capable of binding and inactivating acrolein. Hydralazine in particular can reduce acrolein concentrations and inhibit acrolein-mediated pathologies in vivo. Acrolein scavenging appears to be a novel effective treatment, which is primed for rapid translation to the clinic.

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.

Neuroleptic malignant syndrome and malignant hyperthermia. Important issues for the medical consultant

Neuroleptic malignant syndrome and malignant hyperthermia share two cardinal clinical features: hypothermia and rigidity. Both syndromes can result in rhabdomyolysis and have high mortality rates if left untreated. This article reviews each syndrome and its pathogenesis and treatment.

Treatment of Panic Disorder

In 1981, panic disorder was officially recognized as a separate illness and not merely a component of generalized anxiety disorder. Panic disorder is characterized by panic attacks or unpredictable episodes of sudden and overwhelming feelings of fear or terror. The disorder has a lifetime prevalence rate of 1.6% to 2%, being more common in women than men; many patients do not seek treatment. The majority of patients who have panic disorder develop severe anxiety and agoraphobia; comorbidity with depression occurs in approximately 33%. Panic disorder seems to be chronic with significant morbidity and mortality, including suicide, in patients who are untreated. Fortunately, panic disorder can be successfully treated using several drugs, including antidepressants, imipramine and phenelzine, and the benzodiazepine, alprazolam. It is anticipated that the Federal Food and Drug Administration (FDA) will soon approve the first antipanic drug, alprazolam (Xanax, Upjohn, Kalamazoo, MI). The drug of choice for panic disorder is determined by careful evaluation of several drug and patient characteristics. Although alprazolam has some distinct advantages over the antidepressants, including faster onset of therapeutic response and greater patient acceptance, the major problem is drug dependence and withdrawal, especially after high-dose, long-term use. Alprazolam should never be abruptly discontinued, but slowly tapered according to individual response. The pharmacist can play a valuable role in educating patients regarding the efficacy of drug treatment, risks and benefits of individual therapeutic agents, as well as the risks of untreated panic disorder.

Clinical features, pathogenesis and management of drug-induced rhabdomyolysis

Striated musculature is considered unusually tolerant to all kinds of injuries, and rhabdomyolysis associated with drug overdose or chronic drug intake is a rare event. This may be because striated musculature, in contrast to other tissues such as liver and kidney, shows little affinity for most drugs. Several different types of drug-induced rhabdomyolysis may be distinguished, and the clinical features of the condition may vary widely, from moderate myalgia to involvement of groups of muscles to involvement of the total skeletal musculature. In clinically asymptomatic rhabdomyolysis, early diagnosis is only made if routine laboratory tests include determination of serum creatine kinase. Determination of myoglobin in serum and urine is more sensitive and allows earlier diagnosis of muscle necrosis. Myoglobinaemia may lead to toxin-induced tubular necrosis, and impairment of renal function or even acute renal failure. About 10% of all cases of acute renal failure are due to rhabdomyolysis. Fulminant rhabdomyolysis may be associated with excessive hyperkalaemia and hypocalcaemia which may induce further life-threatening complications. Therefore, early diagnosis of rhabdomyolysis is most important for prevention of its potentially life-threatening sequelae. Therapy of rhabdomyolysis consists of supportive and specific measures. Early diagnosis may help to prevent life-threatening sequelae like acute renal failure, electrolyte imbalance and shock. Withdrawal of the incriminated drug or detoxification in drug overdose should be followed by supportive measures including infusion therapy and correction of dehydration and electrolyte imbalances. Forced diuresis with sodium bicarbonate may protect the kidney function from acidosis and precipitation of myoglobin in tubules. Elimination of myoglobin from plasma may be enhanced by plasmapheresis. In patients with acute renal failure, haemodialysis is necessary. In malignant hyperthermia, immediate infusion of dantrolene sodium is required. This drug also seems to have a beneficial effect in neuroleptic malignant syndrome. The repair mechanisms of striated musculature function extremely well. The prognosis of muscular atrophy after the acute stage of rhabdomyolysis is excellent. The same is true for the prognosis of acute renal failure. However, the extent of complications or survival of the acute stage of rhabdomyolysis strongly depend on early diagnosis and start of adequate therapy.

Panic attacks facilitating recall and mastery: implications for psychoanalytic technique

A patient, during the course of a lengthy analysis, experienced several panic attacks. These regressive episodes, occurring only in the analytic setting, provided her with her special means for recalling and eventually mastering repressed elements of her life. This facilitating aspect of her disorganization, when identified and analyzed as such, helped deepen the patient's analytic experience. It was necessary for the analyst to define verbally and clarify her reconstructed past as it emerged as part of her panic state, transferentially, so that the patient could finally recognize, acknowledge, and understand hitherto hidden aspects of her life. The psychiatric literature in regard to panic states is briefly noted, as is the relevance of comparing the present almost exclusively organic, pharmacological orientation, with Freud's discussion of the "actual" or current neuroses of his day, almost a century ago. On the basis of this case report, the importance of understanding the content and meaning of the panic attack, by analytic means, is once again emphasized.

Is monoamine oxidase inhibitor induced myoclonus serotoninergically mediated?

In the present study a single case observation of myoclonus during sleep-wave transition was monitored in a depressed patient treated with the monoamine oxidase inhibitor, phenelzine. The myoclonus had a rhythm of 1 c/second and lasted for two years, the duration of phenelzine treatment. Myoclonus appeared neither during wakefulness nor during sleep, but at wake-sleep-wake transitions. This "switch" myoclonus was associated with phasic muscle hyperactivity during REM sleep. Methysergide a 5-HT suppressor, decreased the switch myoclonus frequency and the REM muscle hyperactivity, indicating serotoninergic involvement in the mechanism of phenelzine induced myoclonus.

Recent developments in the treatment of panic disorder

The focus of this paper is the treatment of panic disorder with alprazolam. Drug treatments alone are sometimes not sufficient by themselves, to adequately control all of the symptoms or components of this disorder. In the typical case we can identify four targets of treatment: The first target is the biological core of the condition, that is characterized by the unexpected, unprovoked attacks of anxiety. This responds best to medication. The second target is the phobic avoidance behaviour. It appears to be a conditioned or learned complication of the biological core, and appears to follow the laws of learning theory. Unlearning treatments, like behaviour therapy (notably in vivo exposure) are usually necessary to make a full impact against the phobic avoidance behaviour. Thirdly, there is no drug that reverses the psycho-social problems these patients have. Not all of them have such problems, but those that do may need psychotherapy to deal with their conflicts and stresses. Finally, the evidence in several chronic studies, suggest that this is a chronic relapsing disorder in the majority of cases. It is not enough to treat these patients acutely. They must be followed chronically and monitored carefully over many years, if they are to be protected against relapse.

The use of monoamine oxidase inhibitors in the treatment of elderly, depressed patients

Depression is an extremely common illness in the elderly, and is, at times, refractory to the usual therapies. The elderly are also particularly prone to develop toxic side effects from standard antidepressive agents. Monoamine oxidase inhibitors are rarely used in this population, although much evidence and clinical experience would indicate that they can be extremely effective and non-toxic. This paper outlines the indications and precautions for use and side effects of monoamine oxidase inhibitors in the treatment of depression in elderly patients.

Antidepressants: a clinical update for medical practitioners

Knowledge of the pharmacologic actions of antidepressants enables the physician to develop an appropriate rationale for the use of these medications in the medical setting. The appropriate choice of drug and adequate dose, duration, maintenance, termination, therapy, and alternatives should be considered.

The diagnosis and drug treatment of anxiety disorders

Anxiety, phobic and related neurotic disorders lend themselves to diagnostic confusion because of the large and variable array of symptoms associated with them. This has complicated attempts at coherent classification. This paper examines the problems in diagnosis and classification and the diversity of causal models of these disorders. It offers an alternative integrated perspective that may have heurestic merit in guiding clinicians to a practical choice of treatment and in delineating a useful starting point for the biological investigation of these disorders.