Withdrawal from high-dose tranylcypromine

Abuse and misuse of antidepressants

BACKGROUND

Rates of prescription drug abuse have reached epidemic proportions. Large-scale epidemiologic surveys of this under-recognized clinical problem have not included antidepressants despite their contribution to morbidity and mortality. The purpose of this review is to look specifically at the misuse of antidepressants and how this behavior may fit into the growing crisis of nonmedical use of prescription drugs.

METHODS

We conducted a comprehensive search on PubMed, Medline, and PsycINFO using the search terms "antidepressant", "abuse", "misuse", "nonmedical use", "dependence", and "addiction", as well as individual antidepressant classes (eg, "SSRI") and individual antidepressants (eg, "fluoxetine") in various combinations, to identify articles of antidepressant misuse and abuse.

RESULTS

A small but growing literature on the misuse and abuse of antidepressants consists largely of case reports. Most cases of antidepressant abuse have occurred in individuals with comorbid substance use and mood disorders. The most commonly reported motivation for abuse is to achieve a psychostimulant-like effect. Antidepressants are abused at high doses and via a variety of routes of administration (eg, intranasal, intravenous). Negative consequences vary based upon antidepressant class and pharmacology, but these have included seizures, confusion, and psychotic-like symptoms.

CONCLUSION

The majority of individuals prescribed antidepressants do not misuse the medication. However, certain classes of antidepressants do carry abuse potential. Vulnerable patient populations include those with a history of substance abuse and those in controlled environments. Warning signs include the presence of aberrant behaviors. Physicians should include antidepressants when screening for risky prescription medication use. When antidepressant misuse is detected, a thoughtful treatment plan, including referral to an addiction specialist, should be developed and implemented.

Intoxications with the monoamine oxidase inhibitor tranylcypromine: an analysis of fatal and non-fatal events

Tranylcypromine (TCP) is a non-selective and irreversible monoamine oxidase inhibitor and an effective agent in the treatment of major depression. It features a complex pharmacologic profile and overdoses might induce severe intoxications. To identify typical clinical presentations of TCP-intoxications, range of associated TCP-dosages and possible differences between fatal and non-fatal intoxications a systematic review of all previously published cases of TCP-intoxications was conducted. We detected n=20 reports of TCP-intoxications in the literature (fatalities n=10). Mean age was 36.7 years (median 37); the majority of patients were female (60%). Frequent findings in patients with TCP-intoxications were disturbance of consciousness/cognitive dysfunction (90%), cardio-vascular symptoms (55%), hyperthermia (50%), respiratory distress (45%), delirium (45%), muscular rigidity (30%) and renal failure (20%). Suicidal intent was present in n=18 (90%) patients. First clinical symptoms related to TCP-intoxication developed on average in less than 1 day. The average dosage related to TCP-intoxication was 677 mg. The highest survived TCP-dosage was 4000 mg and the lowest fatal dosage was 170 mg. Patients with fatal intoxications were on average older (40.5 vs. 32.8 years) and developed a more rapid onset of symptoms (0.2 vs. 0.8 days). Death occurred after a mean time of 0.6 days; symptom relief in patients with non-fatal intoxications developed on average after 3.2 days. Considering the large dose spectrum between survived and lethal TCP-dosages individual susceptibility factors might play a role regarding the severity of clinical symptoms independently of the ingested dosage.

Lysine-specific demethylase 1 is a therapeutic target for fetal hemoglobin induction

Enhanced fetal γ-globin synthesis alleviates symptoms of β-globinopathies such as sickle cell disease and β-thalassemia, but current γ-globin-inducing drugs offer limited beneficial effects. We show here that lysine-specific demethylase 1 (LSD1) inhibition by RNAi in human erythroid cells or by the monoamine oxidase inhibitor tranylcypromine in human erythroid cells or β-type globin-transgenic mice enhances γ-globin expression. LSD1 is thus a promising therapeutic target for γ-globin induction, and tranylcypromine may serve as a lead compound for the development of a new γ-globin inducer.

Advances pertaining to the pharmacology and interactions of irreversible nonselective monoamine oxidase inhibitors

Recent advances clarifying the pharmacology and interactions of irreversible nonselective monoamine oxidase inhibitors that have not been considered in depth lately are discussed. These new data elucidate aspects of enzyme inhibition and pharmacokinetic interactions involving amine oxidases, cytochrome P450 enzymes, aminotransferases (transaminases), and decarboxylases (carboxy-lyases) and the effects of tyramine. Phenelzine and tranylcypromine remain widely available, and many publications have data relevant to this review. Their effect on CYP 450 enzymes is less than many newer drugs. Tranylcypromine only inhibits CYP 450 2A6 (selectively and potently). Phenelzine has no reported interactions, but, like isoniazid, weakly and irreversibly inhibits CYP 450 2C19 and 3A4 in vitro. It might possibly be implicated in interactions (as isoniazid is). Phenelzine has some clinically relevant inhibitory effects on amine oxidases, aminotransferases, and decarboxylases, and it lowers pyridoxal phosphate levels. It commonly causes pyridoxal deficiency, weight gain, sedation, and sexual dysfunction, but only rarely causes hepatic damage and failure, or neurotoxicity. The adverse effects and difficulties with monoamine oxidase inhibitors are less than previously believed or estimated, including a lower risk of hypertension, because the tyramine content in foods is now lower. Potent norepinephrine reuptake inhibitors have a strong protective effect against tyramine-induced hypertension. The newly discovered trace amine-associated receptors probably mediate the pressor response. The therapeutic potential of tranylcypromine and L-dopa in depression and Parkinson disease is worthy of reassessment. Monoamine oxidase inhibitors are not used to an extent proportionate with their benefits; medical texts and doctors' knowledge require a major update to reflect the evidence of recent advances.