Hypertensive crisis People taking<unk> s generally need to change their diets to limit or avoid foods and beverages containing tyramine, which is found in products such as cheese, soy sauce, and salami. If large amounts of tyramine are consumed, they may suffer a hypertensive crisis, which can be fatal. Examples of foods and beverages with potentially high levels of tyramine include animal liver and fermented substances, such as alcoholic beverages and aged cheeses. Excessive concentrations of tyramine in blood plasma can lead to hypertensive crisis by increasing the release of norepinephrine (NE), which causes blood vessels to constrict by activating alpha-1 adrenergic receptors. Ordinarily, MAO-A would destroy the excess NE; when MAO-A is inhibited, however, NE levels get too high, leading to dangerous increases in blood pressure. RIMAs are displaced from MAO-A in the presence of tyramine, rather than inhibiting its breakdown in the liver as general<unk> s do. Additionally, MAO-B remains free and continues to metabolize tyramine in the stomach, although this is less significant than the liver action. Thus, RIMAs are unlikely to elicit tyramine-mediated hypertensive crisis; moreover, dietary modifications are not usually necessary when taking a reversible inhibitor of MAO-A (i.e., moclobemide) or low doses of selective MAO-B inhibitors (e.g., selegiline 6 mg/24 hours transdermal patch). Drug interactions The most significant risk associated with the use of<unk> s is the potential for drug interactions with over-the-counter, prescription, or illegally obtained medications, and some dietary supplements (e.g., St. John's wort, tryptophan). It is vital that a doctor supervise such combinations to avoid adverse reactions. For this reason, many users carry an<unk> -card, which lets emergency medical personnel know what drugs to avoid (e.g. adrenaline epinephrine dosage should be reduced by 75%, and duration is extended.) Tryptophan supplements can be consumed with<unk> s, but can result in transient serotonin syndrome.<unk> s should not be combined with other psychoactive substances (antidepressants, painkillers, stimulants, including prescribed, OTC and illegally acquired drugs, etc.) except under expert care. Certain combinations can cause lethal reactions, common examples including SSRIs, tricyclics, MDMA, meperidine, tramadol, and dextromethorphan. Drugs that affect the release or reuptake of epinephrine, norepinephrine, or dopamine typically need to be administered at lower doses due to the resulting potentiated and prolonged effect.<unk> s also interact with tobacco-containing products (e.g. cigarettes) and may potentiate the effects of certain compounds in tobacco. This may be reflected in the difficulty of smoking cessation, as tobacco contains naturally occurring<unk>  compounds in addition to the nicotine. While safer than general<unk> s, still possess significant and potentially serious drug interactions with many common drugs; in particular, they can cause serotonin syndrome or hypertensive crisis when combined with almost any antidepressant or stimulant, common migraine medications, certain herbs, or most cold medicines (including decongestants, antihistamines, and cough syrup). Ocular alpha-2 agonists such as brimonidine and apraclonidine are glaucoma medications which reduce intraocular pressure by decreasing aqueous production. These alpha-2 agonists should not be given with oral<unk> s due to the risk of hypertensive crisis. Withdrawal Antidepressants including<unk> s have some dependence-producing effects, the most notable one being a discontinuation syndrome, which may be severe especially if<unk> s are discontinued abruptly or too rapidly. The dependence-producing potential of<unk> s or antidepressants in general is not as significant as benzodiazepines, however. Discontinuation symptoms can be managed by a gradual reduction in dosage over a period of days, weeks or sometimes months to minimize or prevent withdrawal symptoms.<unk> s, as with most antidepressant medication, may not alter the course of the disorder in a significant, permanent way, so it is possible that discontinuation can return the patient to the pre-treatment state. This consideration complicates prescribing between an<unk>  and an SSRI, because it is necessary to clear the system completely of one drug before starting another. One physician organization recommends the dose to be tapered down over a minimum of four weeks, followed by a two week washout period. The result is that a depressed patient will have to bear the depression without chemical help during the drug-free interval. This may be preferable to risking the effects of an interaction between the two drugs.
Monoamine oxidase inhibitor
Acetylcholinesterase inhibitor
Dopamine antagonist
Enkephalinase inhibitor
Monoamine reuptake inhibitor
Norepinephrine reuptake inhibitor
Glycine reuptake inhibitor
Opioid antagonist