Antidepressants and antipsychotics as hypnotics?

[EN21]

I am searching for some information for the use of antidepressants and neuroleptic agents in the treatment of insomnia.
Can there be a trend observed? Can they ever displace the benzos?
During my search, I found that not only the antihistaminic properties are responsible for the hypnotic effect of such drugs. There is often the 5-HT2A antagonism speculated also to be involved in the sedation.
Has anybody a good reference for sedating effects of 5-HT antagonists?

Thanks,
EN21

 

[jasoncrest]

Some antidepressants are commonly prescribed for insomnia, mainly Amitriptyline and Mirtazapine (Remeron). They are sedative because they have a strong sedative action.

Some antipsychotics are even more often aften prescribed against insomnia.
In the past it was Thorazine/Chlorpromazine; now it's Seroquel (quietapine).
It's sedative effect are caused by it's 5-HT, adrenergic, antihistamine and dopamine antagonist properties.

From RxList:

SEROQUEL is an antagonist at multiple neurotransmitter receptors in the brain: serotonin 5HT1A and 5HT2 (IC50s=717 & 148nM respectively), dopamine D1 and D2 (IC50s=1268 & 329nM respectively), histamine H1 (IC50=30nM), and adrenergic a1 and a2 receptors (IC50s=94 & 271nM, respectively). SEROQUEL has no appreciable affinity at cholinergic muscarinic and benzodiazepine receptors (IC50s>5000 nM).

 

[Helios.]

lol,
falcon movie studios.

 

[EN21]

Thanks, jasoncrest!
30 nM for the H1 receptor sounds to me that the sedative effects simply result from the antihistaminic effect.
But some butyrophenones, like pipamperon or melperone have no significant affinity for the histamine receptors, but are also very sedative.
In secondary literature they make the 5-HT2a antagonism responsible, but I don't find a scientific article.

 

[Dr.Heckyll]

Trazodone is an antidepressant and a good sleeping aid. Mirtazapine makes you sleep only the first few days you're takling it.

 

[Helios.]

Trazodone is good, but for the truly sleep deprived there's olanzapine and clozaril.

 

[EN21]

Hey, thanks for that notes, what doses are used as a sleep inducer?
less than as antidepressant or rather the same?

 

[jasoncrest]

Hey, thanks for that notes, what doses are used as a sleep inducer?
less than as antidepressant or rather the same?

I think that most often the hypnotic doses are lower than the antidepressant doses.
(for Amitriptyline, 25mg is a good hypnotic dose, antidepressant doses go up to 100mg/day and more)
(for Mirtazapine/Remeron, 15mg is a good hypnotic dose, antidepressant doses go up to 60mg/day)

 

[rashandreflex]

^^
yes and for seroquel, doses for psychosis and bipolar disorder range from 200 mg or so (on the low end) up to sometimes as high as 1500 mg a day, but for sleep purposes 25-50 mg usually suffices

however, i think to some extent the trouble is breaking the drugs down into these categories 'antidepressant,' 'neuroleptic,' and so on because many of them affect so many neurotransmitters and have many applications....it is almost astounding to see how many disorders some medications now treat