Promethazine

[Biochemistry]

Hello,

I would like to know if anybody has used promethazine as an antipsychotic. I am aware that it is structurally related to chlorpromazine as it is in the phenothiazine class, and I also know that it is quite weak in terms of dopamine inhibition. I have melancholic depression with psychotic features (relatively mild psychosis) and OCD, but I am very aware of my psychosis. I believe that I do not need a strong typical or atypical antipsychotic, so I was going to potentially have a trial with promethazine.

Your thoughts would be appreciated.

Cheers.

 

[sekio]

I think using an antihistamine as an antispsychotic is a pretty stupid idea.

 

[Wizzle]

Just use a sufficiently dosed AP, promethazine will sedate you but it will not effectively curb psychosis.

 

[Torabora]

I think using an antihistamine as an antispsychotic is a pretty stupid idea.

ah yes? why is Quetiapin (Seroquel) one of the most prescribed anti psychotics then?

Promethazine seems to share some of its properties with way lower binding affinities but I also think that it is not a proper anti psychotic drug but of course you can try it but I would advise you to talk with you doctor and try Seroquel in low to moderate doses as it is a very good anti psychotic and really helps a lot of people

 

[sekio]

Quetiapine is an antipsychotic that happens to be an antihistamine too. Promethazine is an antihistamine that happens to be antipsychotic. Just because the two drugs share targets doesn't mean they are effective for the same purpose.

 

[Biochemistry]

I think using an antihistamine as an antispsychotic is a pretty stupid idea.

Thank you for the lame response.

Promethazine appears to moderately act on 5-HT2A, 5-HT2C, D2, which is the main reason why I am interested in trying it. Obviously antagonism of only H1 would be useless for psychosis. Therefore, judging by your response, it appears that you're ignorant of how promethazine actually works on the monoamine system.

Quetiapine does not act as an antipsychotic (D1, D2, D3, D4 antagonism) until the dose is around 200mg. I was taking 25mg, at which dose primarily acts as a powerful antihistamine, and it still worked quite well.

Hopefully you can see my logic in trying promethazine.

 

[Wizzle]

The question is why you would want to be more sedated then necessary. The sedative action of antihistamines is generally not considered as something pleasurable, if anything you'd be best of with an AP with as little sedation as possible.

Unless of course, you need the sedation for sleep..

 

[Epsilon Alpha]

Well I'm basing this under the assumption you're undergoing a bitching case of stimulant psychosis, so it might work. My only big concern is that its a local anesthetic, which means its going to be a sodium channel blocker, which means heart problems at very high doses.

Take the maximum recommended dose, and see a doctor if you're having long term issues. You don't want to up your dose one day and have a heart attack.
Also, for the love of all that is holy keep depression threads out of ADD.

Also, quetiapine mainly acts as an "anti-psychotic" via antagonism at 5HT2A at low doses. Hope this clarifies, but seriously man see a doctor.

 

[Biochemistry]

Well I'm basing this under the assumption you're undergoing a bitching case of stimulant psychosis, so it might work. My only big concern is that its a local anesthetic, which means its going to be a sodium channel blocker, which means heart problems at very high doses.

Take the maximum recommended dose, and see a doctor if you're having long term issues. You don't want to up your dose one day and have a heart attack.
Also, for the love of all that is holy keep depression threads out of ADD.

Also, quetiapine mainly acts as an "anti-psychotic" via antagonism at 5HT2A at low doses. Hope this clarifies, but seriously man see a doctor.

You assumed incorrectly; I do not consume recreational drugs. I have already seen a psychiatrist, and I am on two antidepressant medications (mirtazapine and citalopram) for the melancholic/mild psychotic depression and OCD. There are some days where I have mild hallucinations and mild delusions. I have a tremendous level of self-awareness, and I know when I am feeling psychotic.

Anyway, as regards promethazine, I tried my first pill this morning (now evening in UK), and I must say that I am pleasantly surprised with its antipsychotic efficacy. For all of you doubters out there, it is definitely a neuroleptic medication that has a moderate affinity for the D2 receptor, in terms of antagonism; I can definitely feel the antipsychotic effects of it. For instance, I am no longer having "magical" thoughts, mild hallucinations, mild delusions, paranoia or social anxiety. Maybe there is an element of placebo in there, but promethazine is definitely a mild-moderate antipsychotic, which is great because it is OTC in the UK.