Dangerous monoamine oxidase inhibitor interactions are still occurring in the 1990s

Efficacy and Adverse Effects of Tranylcypromine and Tricyclic Antidepressants in the Treatment of Depression: A Systematic Review and Comprehensive Meta-analysis

PURPOSE

We conducted a comprehensive meta-analysis of the comparison of tranylcypromine (TCP) and tricyclic antidepressants (TCAs) in the treatment of depression because such work is lacking in medical scientific literature.

METHODS

Literature was searched for studies of TCP controlled by TCAs in multiple databases and in reviews of TCP and monoamine oxidase inhibitors. The natural logarithm of the odds ratio (logOR) and the pooled logOR according to a fixed effect model were calculated for the numbers of responders and nonresponders.

RESULTS

A total of 227 studies of TCP were found including 75 controlled studies of TCP-monotherapy. Twelve of 23 studies of TCP monotherapy and TCAs were excluded for several reasons (duplicates, safety studies, retrospective, cross-over), leaving 11 prospective and parallel controlled studies of TCP monotherapy versus TCAs (6 randomized double-blind). One study was excluded from the meta-analysis because of low quality of study design according to the Food and Drug Administration guidelines of studies of antidepressant drugs and high risk of bias according to the Cochrane's tool. Two studies with equal efficacy of TCP and TCAs in continuous endpoints did not provide dichotomous response data. A pooled logOR of 0.480 (95% confidence interval, 0.105-0.857, P = 0.01) resulted for the remaining eight studies in the primary meta-analysis, which favors TCP significantly over TCAs (test for heterogeneity: Х = 8.1, df = 7, P > 0.3, not heterogenous; I = 13.6%, heterogeneity not important). The result is robust with respect to inclusion of hypothetical response data of the 2 studies with continuous data only: pooled logOR, 0.350 (95% confidence interval, 0.028-0.672, P = 0.03). Visual inspection of forest plots and subgroup analysis suggest that superiority of TCP over TCAs is determined by 2 studies in psychomotor-retarded (anergic) depression.

CONCLUSIONS

Tranylcypromine and TCAs have an equal antidepressant effect in a mean sample of depressed patients with mixed psychomotor symptoms. Tranylcypromine might be superior to TCAs in depression with predominant psychomotor retardation.

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.

Evidence in immunotherapy for paediatric respiratory allergy: Advances and recommendations

Allergic respiratory diseases are major health problems in paediatric population due their high level of prevalence and chronicity, and to their relevance in the costs and quality of life. One of the most important risk factors for the development of airway diseases in children and adolescents is atopy. The mainstays for the treatment of these diseases are avoiding allergens, controlling symptoms, and preventing them through sustained desensitization by allergen immunotherapy (AIT). AIT is a treatment option that consists in the administration of increasing amounts of allergens to modify the biological response to them, inducing long-term tolerance even after treatment has ended. This treatment approach has shown to decrease symptoms and improve quality of life, becoming cost effective for a large number of patients. In addition, it is considered the only treatment that can influence the natural course of the disease by targeting the cause of the allergic inflammatory response. The aim of this publication is to reflect the advances of AIT in the diagnosis and treatment of allergic respiratory diseases in children and adolescents reviewing articles published since 2000, establishing evidence categories to support the strength of the recommendations based on evidence. The first part of the article covers the prerequisite issues to understand how AIT is effective, such as the correct etiologic and clinical diagnosis of allergic respiratory diseases. Following this, the article outlines the advancements in understanding the mechanisms by which AIT achieve immune tolerance to allergens. Administration routes, treatment regimens, dose and duration, efficacy, safety, and factors associated with adherence are also reviewed. Finally, the article reviews future advances in the research of AIT.

Adverse Psychiatric Effects Associated with Herbal Weight-Loss Products

Obesity and overeating are among the most prevalent health concerns worldwide and individuals are increasingly using performance and image-enhancing drugs (PIEDs) as an easy and fast way to control their weight. Among these, herbal weight-loss products (HWLPs) often attract users due to their health claims, assumed safety, easy availability, affordable price, extensive marketing, and the perceived lack of need for professional oversight. Reports suggest that certain HWLPs may lead to onset or exacerbation of psychiatric disturbances. Here we review the available evidence on psychiatric adverse effects of HWLPs due to their intrinsic toxicity and potential for interaction with psychiatric medications.

Clinical contraindications to allergen immunotherapy: an EAACI position paper

Clinical indications for allergen immunotherapy (AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as 'absolute' or 'relative'. EAACI Task Force on 'Contraindications to AIT' was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β-blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT-related side-effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient.

The pharmacological properties of antidepressants

Antidepressant drugs represent one of the main forms of effective treatment for the amelioration of depressive symptoms. Most available antidepressants increase extracellular levels of monoamines. However, it is now recognized that monoamine levels and availability are only part of the story, and that antidepressants whose mechanism of action is mainly based on the modulation of monoaminergic systems may not be able to satisfy the unmet needs of depression. Therefore, a number of compounds, developed for their potential antidepressant activity, are endowed with putative mechanisms of action not affecting traditional monoamine targets. This article briefly reviews, within a mechanistic perspective, the pharmacological profiles of representative antidepressants from each class, including monoamine oxidase inhibitors, tricyclics, norepinephrine reuptake inhibitors, selective serotonin reuptake inhibitors, norepinephrine and serotonin reuptake inhibitors, antidepressants interacting with dopaminergic, melatonergic, glutamatergic, or neuropeptide systems. The undesirable side effects of currently used antidepressants, which can often be a reason for lack of compliance, are also considered.

Evaluation of the potential for pharmacodynamic and pharmacokinetic drug interactions between selegiline transdermal system and two sympathomimetic agents (pseudoephedrine and phenylpropanolamine) in healthy volunteers

Selegiline transdermal system is a recently approved monoamine oxidase inhibitor antidepressant. Medications that inhibit monoamine oxidase type A can augment the pressor effects of sympathomimetic amines, increasing the potential for hypertensive crisis. This study examined the potential for drug-drug interactions during treatment with selegiline transdermal system and pseudoephedrine or phenylpropanolamine. Two studies were conducted with 25 healthy volunteers to assess changes in blood pressure and heart rate during administration of pseudoephedrine or phenylpropanolamine alone or together with selegiline transdermal system. No significant differences in mean maximum changes in vital signs occurred with pseudoephedrine. No significant differences were found in mean maximum changes in systolic heart rate with phenylpropanolamine; however, 4 of 12 subjects each experienced 1 isolated protocol-defined minimal pressor response without concurrent adverse effects (1 with phenylpropanolamine alone; 3 with phenylpropanolamine + selegiline transdermal system). Pharmacokinetic parameters obtained following selegiline transdermal system and pseudoephedrine or phenylpropanolamine were unremarkable. The results suggest that selegiline transdermal system 6 mg/24 h does not significantly alter the pharmacodynamics or pharmacokinetics of either pseudoephedrine or phenylpropanolamine when administered to healthy volunteers; however, it is prudent to avoid coadministration of selegiline transdermal system and sympathomimetics.

An evidence-based systematic review of herb and supplement interactions by the Natural Standard Research Collaboration

Reported utilisation of prescription drug use concurrently with herbal or vitamin products have increased, placing an estimated 15 million patients at risk of potential drug-supplement interactions. This systematic review aims to consolidate relevant herb and supplement interactions data available for some of the more common classes of interactions experienced by clinicians. These classes include: hypoglycaemic/hyperglycaemics; hypotensive/hypertensives, diuretics, sedatives, cardiac glycosides, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, laxatives, immunomodulators, agents that may increase the risk of bleeding or clotting, agents that may be hepatotoxic, agents that may have hormonal properties, and agents with cytochrome P450 enzyme activity. The format is designed to promote use as a decision support tool for healthcare providers.

Safety of ephedra: lessons learned

The safe use of ephedra represents the best possible outcome of a convergence of variables, some with troubling potential outcomes. Commercially used ephedra and its products is prepared from Ephedra spp. and as such is subject to a variety of influences (including differences in species and strain; growth, harvest and storage conditions) all of which may influence the content of constituents (which may, in turn, affect the absorption, distribution, and metabolism of active constituents) and taken together, influences the net pharmacological effect. Further, as a natural substance with an easily perceived and desirable (i.e. weight-loss) pharmacological effect, ephedra is also susceptible to a variety of adulterants, both economic and efficacious. All of the foregoing represent potential for misadventure before ephedra even reaches the consumer. The consumer introduces a constellation of variables as well, including, but not limited to, acute and chronic diseases, inborn errors in metabolism, simultaneous use of prescription and over-the-counter drugs, dietary supplements, alcohol, illicit substances and certain foods (e.g. chocolate, caffeinated drinks), all or some of which may exert synergistic, additive or even antagonistic influences on the desired physiologic outcome. The foregoing not withstanding, the majority of the published nonclinical and clinical studies, and history of use, support the safety of ephedra at the proposed use levels. However, the reports of adverse events submitted to FDA raise concern about the risk associated with ephedra without establishing a direct causal relationship. Given the foregoing, how best can a decision on safety be made? Should the question actually be "can ephedra be as toxic as reported?"

Herbal and alternative medicine

An extensive range of herbal and dietary supplements is now available, and use of these products by ED patients is fairly common. Emergency physicians should be familiar with some of the products used more frequently for common complaints. Emergency personnel also should be vigilant for toxic syndromes resulting from ingestion of certain of these products and be wary of possible toxicity from any of these supplements owing to their minimal quality control and absence of FDA regulation.