TTA - TeTeracyclic Antidepressant
Also referred to as a TetraCyclic Antidepressant (TCA)
The term "tetracyclic antidepressant" specifically refers to the chemical structure of the compounds in question, which structurally possess four rings. Only two drugs of this family are frequently used - maprotiline and mirtazapine.
Amoxapine
Amoxapine is classed frequently as a tricyclic antidepressant, yet it is structurally a tetracyclic drug; it is listed here for the sake of completeness. The mode of action is in the inhibition of the monoamine neurotransmitter noradrenaline and, to a far lesser extent, the monoamine neurotransmitter serotonin.
Maprotiline
Maprotiline strongly inhibits the reuptake of the monoamine neurotransmitter noradrenaline and also impact on the monoamine neurotransmitters dopamine and serotonin, albeit to a far lesser extent; this makes the drug an SSNaDRI antidepressant (this category is not presently listed here on Seratis but will be added in due course). The medication is sedative and has anxiolytic effect - it is considered to be a second generation antidepressant. Side effects-wise, the drug is comparable with typical tricyclic antidepressants but due to certain more shifty potential problems patients should undergo frequent blood tests and, in some cases, EEG and/or EKG tests as well.
Pleased note that this drug may well worsen psychotic symptoms and should be used with care.
Mianserin
An interesting drug, mianserin doesn't so much inhibit the reuptake of the monoamine neurotransmitter noradrenaline as it does encourage its production. The drug has largely been phased out at the time of writing in favour of the medication mirtazapine of the same family.
Mirtazapine
Introduced in 1996, mirtazapine is chemically a tetracyclic antidepressant but is primarily labelled as an NaSSA due to its mode of action. It is listed here for the sake of completeness.
Mirtazapine is a viable first line treatment amongst drugs; it is effective and boasts a very small side effect profile, one which mostly lacks anticholinergic, adrenolytic or serotonin related side effects (as commonly exhibited by the popular SSRI antidepressant family). It is sedative and as such is a viable treatment for anxiety and stress related disorders or where insomnia is a symptom of the illness.
Major side effects include sedation (54%), a dry mouth (25%), an increased appetite (17%), weight gain (12%) and dizziness (7%). The most serious side effect is agranulocytosis but this is very rare indeed; the chance of experiencing this is approximately one in one thousand. Mirtazapine is relatively safe in overdose.
Nefazodone
Most closely related to the tetracyclic antidepressant trazodone and a tetracyclic compound itself, nefazodone is fairly novel in its therapeutic effects; it is usually considered primarily to be an SSNaRI antidepressant. Due to a potentially fatal but small possibility of liver damage, this drug was withdrawn from sale to some extent in 2003 but is still readily available the world over. This particular antidepressant is neutral in various fields where most others are not; it tends not to cause sexual dysfunction in patients and tends not to have any impact on ones quality of sleep; it also proved to be effective where more conventional antidepressants failed.
Setiptiline
I have no information on this drug at this time.
Trazodone
No. 7 most prescribed antidepressant, 2005
Although trazodone does selectively inhibit the reuptake of the monoamine neurotransmitter serotonin, it is not typically regarded as an SSRI as it is believed that its antidepressant effect is caused by another mode of action. However, in terms of side effects it is fairly similar to SSRI antidepressants in general; in particular, it sports the usual discontinuation syndrome.
Seemingly a wonderdrug, trazodone is a sedative antidepressant that has proven useful in the treatment of anxiety related disorders. Seemingly, this drug starts to take hold within the first week of therapy, three to four times faster than typical antidepressants. The drug also has a far smaller side effects profile than typical antidepressants in virtually all facets (sexual problems, anticholinergic and adrenolytic side effects, amongst others). Curiously, it does interact with some foodstuffs, most notably grapefruit juice - whilst one glass is unlikely to have any effect whatsoever, large amounts are discouraged. The most common side effects include the said sedation, nausea and/or vomiting, headaches and a dry mouth.
Trazodone is, as was previiously mentioned, a sedative drug; as such it is useful as a treatment for insomnia and fibromyalgia, either in the short term or the long term.