Patients with mixed intoxications (e.g. with other CNS active drugs) may show severe or life-threatening symptoms and should be hospitalized. Treatment is largely symptomatic and should be aimed at maintenance of the vital functions. Withdrawal symptoms appear to be very rare with moclobemide compared to other antidepressants; a single report of relatively mild flu-like symptoms persisting for 7 days after rapid reduction of high dose moclobemide therapy has been reported in one patient. Withdrawal of moclobemide causes a rebound in REM sleep. Moclobemide does not seem to prevent withdrawal symptoms from serotonin reuptake inhibitors. Discontinuation of moclobemide is recommended to be done gradually to minimise side effects (e.g. rapid return of condition being treated and/or the appearance of withdrawal symptoms). Tolerance to the therapeutic effects has been reported in a small number of users of MAOIs including moclobemide. Moclobemide is a benzamide, derivative of morpholine, which acts pharmacologically as a selective, reversible inhibitor of monoamine oxidase A (RIMA), a type of monoamine oxidase inhibitor (MAOI), and increases levels of norepinephrine (noradrenaline), dopamine, and especially serotonin. in neuronal cells as well as in synaptic vesicles; extracellular levels also increase which results in increased monoamine receptor stimulation and suppression of REM sleep, down regulation of Beta-3 adrenergic receptors. A single 300 mg dose of moclobemide inhibits 80% of monoamine oxidase A (MAO-A) and 30% of monoamine oxidase B (MAO-B), blocking the decomposition of norepinephrine, serotonin and, to a lesser extent, dopamine. There is also some evidence of moclobemide possessing neuroprotective properties in rodent models. There is no cumulative effect of moclobemide centrally when taken long-term. With long-term use of moclobemide, there is a significant down-regulation of B-adrenoceptors. Single or repeated dosing with 100–300 mg of moclobemide leads to a reduction in deaminated metabolites of amines such as 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenylethylglycol as well as 5-HIAA.