Phenelzine Health Dictionary

Phenelzine: From 3 Different Sources


A monoamine oxidase inhibitor antidepressant drug usually given when other antidepressant drugs are ineffective.

Possible side effects include dizziness, drowsiness, and rash, and, when taken with certain foods or other drugs, a dangerous rise in blood pressure.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
An example of the widely used ANTIDEPRESSANT DRUGS which are classi?ed as MONOAMINE OXIDASE INHIBITORS (MAOIS). The drug is particularly useful because its stimulant e?ect is less than that of most other MAOIs.
Health Source: Medical Dictionary
Author: Health Dictionary

Antidepressant

Literally, substances meant to oppose depressions or sadness, and generally heterocyclic types such as Elavil, MAO inhibitors like phenelzine, or lithium carbonate. This category of substances formerly included stuff like amphetamines and other stimulants. Our only plants that could fit the current definition would be Hypericum, Peganum and perhaps Oplopanax.... antidepressant

Antidepressant Drugs

These widely used drugs include a range of different preparations which relieve DEPRESSION. All the antidepressants available at the time of writing are more or less equally e?ective. In studies where patients agree to take either antidepressants or identical dummy PLACEBO pills (without knowing which), at least two-thirds of those who receive antidepressants feel much better within three months, while fewer than one-third of those on placebos recover naturally in the same period. In general these drugs are useful for severe and moderate depression including postnatal illness; they are not e?ective in milder forms of depression although they may be tried for a short time if other therapies have failed.

The most widely prescribed type of antidepressants are the tricyclics, so-called because their molecular structure includes three rings. The other commonly used types are named after the actions they have on chemicals in the brain: the SELECTIVE SEROTONIN-REUPTAKE INHIBITORS (SSRIS) and the MONOAMINE OXIDASE INHIBITORS (MAOIS) – see also below. All types of antidepressant work in similar ways. Tricyclic antidepressants have cured depression in millions of people, but they can cause unpleasant side-effects, particularly in the ?rst couple of weeks. These include SEDATION, dry mouth, excessive sweating, CONSTIPATION, urinary problems, and impotence (inability to get an erection). Up to half of all people prescribed tricyclic drugs cannot tolerate the side-effects and stop treatment before their depression is properly treated. More seriously, tricyclics can upset the rhythm of the heart in susceptible people and should never be given in the presence of heart disease.

The SSRIs are newer, coming into wide use in the late 1980s. They increase the levels in the brain of the chemical messenger SEROTONIN, which is thought to be depleted in depression. Indeed, the SSRIs are as e?ective as tricyclics and, although they can cause nausea and excessive sweating at ?rst, they generally have fewer side-effects. Their main disadvantage, however, is that they cost much more than the most commonly used tricyclic, amitriptyline. On the other hand, they are more acceptable to many patients and they cause fewer drop-outs from treatment – up to a quarter rather than a half. The money saved by completed, successful treatment may outweigh the prescribing costs. SSRIs have been reported as associated with an increased risk of suicide.

Another group of antidepressants, the MAOIs, have been in use since the late 1950s.

They are stimulants, rather than sedatives, and are particularly helpful for people who are physically and mentally slowed by depression. They work well but have one big disadvantage – a dangerous interaction with certain foods and other drugs, causing a sudden and very dangerous increase in blood pressure. People taking them must carry an information card explaining the risk and listing the things that they should avoid. Because of this risk, MAOIs are not used much now, except when other treatments have failed. A new MAOI, moclobemide, which is less likely to interact and so cause high blood pressure, is now available.

LITHIUM CARBONATE is a powerful antidepressant used for intractable depression. It should be used under specialist supervision as the gap between an e?ective dose and a toxic one is narrow.

St John’s Wort is a popular herbal remedy which may be e?ective, but which is handicapped by di?erences of strength between di?erent preparations or batches. It can interact with a number of conventional drugs and so needs to be used cautiously and with advice.

In general, antidepressants work by restoring the balance of chemicals in the brain. Improved sleep and reduced anxiety are usually the ?rst signs of improvement, particularly among people taking the more sedative tricyclic drugs. Improvement in other symptoms follow, with the mood starting to lift after about two weeks of treatment. Most people feel well by three months, although a few residual symptoms, such as slowness in the mornings, may take longer to clear up. People taking antidepressants usually want to stop them as soon as they feel better; however, the risk of relapse is high for up to a year and most doctors recommend continuing the drugs for around 4–6 months after recovery, with gradual reduction of the dose after that.

Withdrawal reactions may occur including nausea, vomiting, headache, giddiness, panic or anxiety and restlessness. The drugs should be withdrawn gradually over about a month or longer (up to six months in those who have been on maintenance treatment).

A wide range of antidepressant drugs is described in the British National Formulary. Examples include:

Tricyclics: amitryptyline, imipramine, doxepin.

MAOIs: phenelzine, isocarboxazid.

SSRIs: citalopram, ?uoxetine, paraxtene. (Antidepressant drugs not in these three

groups include ?upenthixol, mertazapine and venlafaxine.)... antidepressant drugs

Monoamine Oxidase Inhibitors

Also known as MAOIs, one of the 3 main types of antidepressant drug.

They work by preventing the breakdown of certain neurotransmitters by the enzyme monoamine oxidase.

The increased levels of neurotransmitters that result are associated with improved mood.

Common drugs include phenelzine and isocarboxazid.

All MAOIs interact with certain other drugs and foods such as cheese and red wine; but moclobemide is known as a reversible , which makes the adverse reactions less likely to occur.... monoamine oxidase inhibitors

Cacao

Chocolate (Theobroma cacao).

Plant Part Used: Leaf, seeds.

Dominican Medicinal Uses: The seeds are traditionally prepared as a tea by decoction (i.e. hot chocolate) taken orally for fatigue and weakness. The leaf decoction is used for kidney and urinary tract disorders.

Safety: Chocolate is widely consumed and generally regarded as safe. No data on the safety of the leaf has been identified in the available literature.

Contraindications: Avoid use in individuals with a history of heart disorders (due to cardiac stimulant effects) or hypersensitivity (due to potential skin reactions or migraines).

Drug Interactions: Avoid concomitant use with phenelzine due to potential for high blood pressure. The following medications may inhibit caffeine metabolism or clearance: oral contraceptives, cimetidine, furafylline, verapamil, disulfiram, fluconoazole, mexiletine, phenylpropanolamine, numerous quinolone antibiotics (i.e. enoxacin, pipemidic acid, ciprofloxacin, norfloxacin), idrocilamide and methoxsalen.

Clinical Data: The following effects of the seed extract have been investigated in human clinical trials: anti-ulcer, antioxidant and decreased platelet function.

Laboratory & Preclinical Data: In animal studies the seed extract has shown anti-ulcer effects. In vitro the seed extracts and/or constituents have shown antibacterial, antioxidant, anti-tumor, cardio-protective, dopaminergic, immunomodulatory and red blood cell production stimulant effects.

* See entry for Cacao in “Part 3: Dominican Medicinal Plant Profiles” of this book for more information, including references.... cacao

Monoamine Oxidase Inhibitors (maois)

These are drugs that destroy, or prevent the action of, monoamine oxidase (MAO). Monoamines, which include NORADRENALINE and tyramine, play an important part in the metabolism of the BRAIN, and there is some evidence that excitement is due to an accumulation of monoamines in the brain. MAO is a naturally occurring ENZYME which is concerned in the breakdown of monoamines. MAOIs were among the earliest ANTIDEPRESSANT DRUGS used, but they are now used much less than tricyclic and related antidepressants, or SELECTIVE SEROTONIN-REUPTAKE INHIBITORS (SSRIS) and related antidepressants, because of the dangers of dietary or drug interactions – and because MAOIs are less e?ective than these two groups.

An excessive accumulation of monoamines can induce a dangerous reaction characterised by high blood pressure, palpitations, sweating and a feeling of su?ocation. Hence the care with which MAOI drugs are administered. What is equally important, however, is that in no circumstances should a patient receiving any MAOI drug eat cheese, yeast preparations such as Marmite, tinned ?sh, or high game. The reason for this ban is that all these foodstu?s contain large amounts of tyramine which increases the amount of certain monoamines such as noradrenaline in the body. (See MENTAL ILLNESS.)

There are also certain drugs, such as AMPHETAMINES and PETHIDINE HYDROCHLORIDE, which must not be taken by a patient who is receiving an MAOI drug. The MAOIs of choice are phenelzine or isocarboxazid because their stimulant effects are less than those of other MAOIs, making them safer.... monoamine oxidase inhibitors (maois)

Mao Inhibitor

(MAOI) a drug that prevents the activity of the enzyme *monoamine oxidase (MAO). MAO inhibitors include phenelzine, isocarboxazid, and tranylcypromine. These drugs are irreversible inhibitors of monoamine oxidase A, whose use as antidepressants is now restricted because of the severity of their side-effects. These include interactions with other drugs (e.g. ephedrine, phenylephrine) and with foods or drinks containing *tyramine (e.g. cheese or red wine) to produce a sudden and dangerous increase in blood pressure. *Moclobemide is a reversible inhibitor of monoamine oxidase A (RIMA), with less severe side-effects. See also selegiline.... mao inhibitor

Depression

Depression is a word that is regularly misused. Most people experience days or weeks when they feel low and fed up (feelings that may recur), but generally they get over it without needing to seek medical help. This is not clinical depression, best de?ned as a collection of psychological symptoms including sadness; unhappy thoughts characterised by worry, poor self-image, self-blame, guilt and low self-con?dence; downbeat views on the future; and a feeling of hopelessness. Su?erers may consider suicide, and in severe depression may soon develop HALLUCINATIONS and DELUSIONS.

Doctors make the diagnosis of depression when they believe a patient to be ill with the latter condition, which may affect physical health and in some instances be life-threatening. This form of depression is common, with up to 15 per cent of the population suffering from it at any one time, while about 20 per cent of adults have ‘medical’ depression at some time during their lives – such that it is one of the most commonly presenting disorders in general practice. Women seem more liable to develop depression than men, with one in six of the former and one in nine of the latter seeking medical help.

Manic depression is a serious form of the disorder that recurs throughout life and is manifested by bouts of abnormal elation – the manic stage. Both the manic and depressive phases are commonly accompanied by psychotic symptoms such as delusions, hallucinations and a loss of sense of reality. This combination is sometimes termed a manic-depressive psychosis or bipolar affective disorder because of the illness’s division into two parts. Another psychiatric description is the catch-all term ‘affective disorder’.

Symptoms These vary with the illness’s severity. Anxiety and variable moods are the main symptoms in mild depression. The sufferer may cry without any reason or be unresponsive to relatives and friends. In its more severe form, depression presents with a loss of appetite, sleeping problems, lack of interest in and enjoyment of social activities, tiredness for no obvious reason, an indi?erence to sexual activity and a lack of concentration. The individual’s physical and mental activities slow down and he or she may contemplate suicide. Symptoms may vary during the 24 hours, being less troublesome during the latter part of the day and worse at night. Some people get depressed during the winter months, probably a consequence of the long hours of darkness: this disorder – SEASONAL AFFECTIVE DISORDER SYNDROME, or SADS – is thought to be more common in populations living in areas with long winters and limited daylight. Untreated, a person with depressive symptoms may steadily worsen, even withdrawing to bed for much of the time, and allowing his or her personal appearance, hygiene and environment to deteriorate. Children and adolescents may also suffer from depression and the disorder is not always recognised.

Causes A real depressive illness rarely has a single obvious cause, although sometimes the death of a close relative, loss of employment or a broken personal relationship may trigger a bout. Depression probably has a genetic background; for instance, manic depression seems to run in some families. Viral infections sometimes cause depression, and hormonal disorders – for example, HYPOTHYROIDISM or postnatal hormonal disturbances (postnatal depression) – will cause it. Di?cult family or social relations can contribute to the development of the disorder. Depression is believed to occur because of chemical changes in the transmission of signals in the nervous system, with a reduction in the neurochemicals that facilitate the passage of messages throughout the system.

Treatment This depends on the type and severity of the depression. These are three main forms. PSYCHOTHERAPY either on a one-to-one basis or as part of a group: this is valuable for those whose depression is the result of lifestyle or personality problems. Various types of psychotherapy are available. DRUG TREATMENT is the most common method and is particularly helpful for those with physical symptoms. ANTIDEPRESSANT DRUGS are divided into three main groups: TRICYCLIC ANTIDEPRESSANT DRUGS (amitriptyline, imipramine and dothiepin are examples); MONOAMINE OXIDASE INHIBITORS (MAOIS) (phenelzine, isocarboxazid and tranylcypromine are examples); and SELECTIVE SEROTONIN REUPTAKE INHIBITORS (SSRIS) (?uoxetine – well known as Prozac®, ?uvoxamine and paroxetine are examples). For manic depression, lithium carbonate is the main preventive drug and it is also used for persistent depression that fails to respond to other treatments. Long-term lithium treatment reduces the likelihood of relapse in about 80 per cent of manic depressives, but the margin between control and toxic side-effects is narrow, so the drug must be carefully supervised. Indeed, all drug treatment for depression needs regular monitoring as the substances have powerful chemical properties with consequential side-effects in some people. Furthermore, the nature of the illness means that some sufferers forget or do not want to take the medication. ELECTROCONVULSIVE THERAPY (ECT) If drug treatments fail, severely depressed patients may be considered for ECT. This treatment has been used for many years but is now only rarely recommended. Given under general anaesthetic, in appropriate circumstances, ECT is safe and e?ective and may even be life-saving, though temporary impairment of memory may occur. Because the treatment was often misused in the past, it still carries a reputation that worries patients and relatives; hence careful assessment and counselling are essential before use is recommended.

Some patients with depression – particularly those with manic depression or who are a danger to themselves or to the public, or who are suicidal – may need admission to hospital, or in severe cases to a secure unit, in order to initiate treatment. But as far as possible patients are treated in the community (see MENTAL ILLNESS).... depression




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