Pressor response to tyramine after single 24-hour application of a selegiline transdermal system in healthy males

DSM-IV depression with atypical features: is it valid?

Atypical features were incorporated into the American Psychiatric Association's Diagnostic and Statistical Manual, Fourth Edition (DSM-IV, 1994) as an illness specifier for major depression and dysthymia. The validity of depression with atypical features was supported by differences relative to depression with melancholic features in syndromal symptoms, course of illness, biology, family history, and treatment response. This paper reviews post-DSM-IV literature relevant to the validity of depression with atypical features. Most studies support the pre-DSM-IV findings. Again, course of illness, biological, family, and treatment differences are shown between melancholia and depression with atypical features. Several biologic studies report nondepressed controls have mean values between depressed subjects having atypical features and other depressed patients. This suggests atypical depression is a distinct depressive group rather than a milder form of melancholia. In addition, some studies show distinctions between depressed subjects with atypical features and those having neither atypical nor melancholic features. As depression with atypical features separates not only from melancholia but also from other depressed groups and controls over a range of meaningful distinctions, we conclude it is a valid clinical syndrome, useful both heuristically and in driving treatment decisions.

Selegiline transdermal system: a novel treatment option for major depressive disorder

BACKGROUND

The use of monoamine oxidase inhibitors has declined owing to the risk of hypertensive crisis following the consumption of tyramine-rich foods and the consequent need for dietary tyramine restriction. However, owing to their superior efficacy in treating depression, continued efforts have been made to develop more selective and reversible monoamine oxidase inhibitors. Oral selegiline, at low doses, is a selective monoamine oxidase B (MAO-B) inhibitor, but at higher doses it loses its selectivity and can potentially interact with tyramine. Unfortunately, antidepressant effects of selegiline have been observed only at higher doses. The selegiline transdermal system was developed to deliver sustained selegiline blood concentrations sufficient to selectively inhibit MAO-A and MAO-B in the brain, producing antidepressant effects, without substantially inhibiting MAO-A in the gastrointestinal tract, thereby reducing the risk of hypertensive crisis.

OBJECTIVES

This article reviews the basic pharmacology, as well as efficacy and safety data of selegiline transdermal system for the treatment of depression.

CONCLUSIONS

Selegiline transdermal system is safe and effective in treating major depressive disorder at the dose range of 6 - 12 mg/24 h, without the need for dietary precautions at the 6 mg/24 h dose. No cases of hypertensive crisis were reported in clinical trials, even without dietary restrictions.

Selegiline transdermal system in the treatment of depressive disorders

Selegiline is a selective irreversible inhibitor of monoamine oxidase (MAO)-B during low-dose oral treatment. Additional MAO-A inhibition occurs in higher dose ranges. Selegiline transdermal system (STS) shows a more potent MAO inhibition in comparison with orally administered selegiline, and at minimum doses of 20 mg/20 cm2 patch delivering 6 mg/24 h, no dietary restrictions, including low-tyramine food, are necessary. While oral selegiline has been used for years in the treatment of Parkinson’s disease, the US FDA recently approved the STS for use in treating major depression. Data from three randomized controlled trials showed a significantly better efficacy of STS in the treatment of unipolar major depression in comparison with placebo during 6–8 weeks of treatment. In addition, one long-term randomized controlled trial demonstrated the efficacy of the STS in relapse prevention of unipolar depression over 1 year. A total number of 515 depressed patients received STS during these studies. The tolerability profile of STS without dietary restrictions was excellent. The only side effects that were more frequent than with placebo were application-site reactions. No change in vital parameters and no hypertensive crisis have been recorded. Comparative studies including treatment with established antidepressants and the investigation of bipolar depressed patients and of specific patient subgroups (e.g., anergic and atypical depression) have to follow. The combination of the well-known effectiveness of irreversible MAO inhibitors with a good tolerability profile and a new pharmaceutical form, possibly enhancing compliance, represents a promising further expansion of the pharmacotherapeutic repertoire in the treatment of depression.

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.

Treatment of Primary Progressive Freezing of Gait With High Doses of Selegiline

We report the case of a 76-year-old, right-handed woman with progressive primary freezing of gait. Despite several therapeutic strategies, she continued to worsen to the point that she became confined to a wheelchair. Treatment with selegiline in doses up to 20 mg/d led to marked improvement of the gait disorder. This case illustrates that selegiline can be an option for patients with freezing of gait other than those with Parkinson's disease.