potency of antihistamines

[morphiquet]

hi,

i've searched desperately on google to find something like a list for the relative potencies of antihistaminic drugs (such as we all know them from opioids, benzodiazepines and neuroleptics), but i wasn't successful.

i just know, that diphenhydramin 50mg compares to circa 25 mg doxepin regarding sedation and other antihistaminic effects.

so i could start the list like this:

- diphenhydramin 1
- doxepin 2

can someone help me to enlarge it (i'm especially interested in diphenylpyralin and dimetinden) , or, if such a list already does exist, post it in here

thank you

 

[sarbanes]

I am interested also. Like, is Meclazine comperable to cyclizine (in fine effect)? What are the reasons cyclizine is so expensive, when you can get Benadryl/Doxylamine/Meclizine relatively cheaply? would Meclizine be pretty comperable to cyclizine (aside from relative potencies)?

 

[Edurasaltat]

I'm very interested in this as well.

I can't give any REAL input, but subjectivly for sedation
4mg of Polaramine (Dexchlorpeniramine Maleate) is about as sedating as
25mg of Phenergan (Promethazine Hydrochloride)

...kinda, although Polaramine lasts for less time.

 

[morphiquet]

have you read the studies about the self-administration of mice and monkeys of certain antihistamines?

especially tripelennamin and diphenylpyralin were found to substitute for cocain, while others like pyrilamin or hydroxyzin are covered with negative effects.

i think these facts make this topic even more interesting

 

[bydefinition]

Doxepin is a tricyclicantidepressant (TCA) of yore.
Does this thread have to do with the antihistaminic potentiation of opioid agonists using different antihistamines or do you take these to make you trip or what?
For sleep, I rely on high dose depakote, large dose but only one pill per night restoril and 200mg or so of seroquel.
In a pinch should I need an OTC sleeping aid, I will reach for either DXM/doxylamine cough syrup or, like, 150mg (6 pills) of OTC diphenhydramine.
Valerian root pills and melatonin may or may not be safe or helpful but probably not more than slightly helpful any way.

 

[jasoncrest]

I am interested also. Like, is Meclazine comperable to cyclizine (in fine effect)? What are the reasons cyclizine is so expensive, when you can get Benadryl/Doxylamine/Meclizine relatively cheaply? would Meclizine be pretty comperable to cyclizine (aside from relative potencies)?

Usually, antihistamines from a same family share the same properties (for instance, phenothiazines antihistamines have all the same sedative, anticholinergic, etc... effects)

But it's not the case for antihistamines from the Piperazine.
The common Piperazine antihistamines are:
-Hydroxyzine
-Meclizine
-Cyclizine
-Buclizine

Hydroxyzine and Cyclizine are highly enjoyable with Opiates, they are among the best antihistamines opiate potentiators.
They have nice weak but noticeable sedative effect, etc..

But Meclizine and Buclizine are completelu useless for Opiate potentiation. They will supress the nausea and the itch, sure, but they add no enjoyable effect.

Besides Opiate potentiation, Cyclizine and Hydroxyzine give good effects by themselves (Hydroxyzine is prescribed as an anti-anxiety and sedative drug in many countries), while you get no effet from Meclizine or Buclizine....

 

[Adrenochrome]

I don't care about opiate potentiation I just care about helping me get to sleep and I found this information when i searched:

Four antihistamines (chlorpheniramine, diphenhydramine, hydroxyzine and promethazine) belong to the strongly sedative group. These agents were found to be quite sedating in sleep laboratory studies and/or clinical trials. Moreover, neuropsychological studies demonstrated that they lower alertness and impair performance to a considerable degree; they were also found to shorten sleep latency in the multiple sleep latency test (MSLT).Nine antihistamines (azatadine, brompheniramine, carbinoxamine, clemastine, dimethindene, ketotifen, mequitazine, phenindamine, triprolidine) were found to be relatively less sedative and are thus categorized in the mildly sedative group. Only three of them (brompheniramine, mequitazine, triprolidine) were evaluated through sleep laboratory studies; all three did not considerably affect sleep efficiency parameters, although they were found to interfere somewhat with performance and to induce a degree of sedation subjectively(...)Moreover, tolerance to the sedative effects of brompheniramine, carbinoxamine and clemastine was shown to develop after the first day of drug administration.Finally, nine drugs (astemizole, cetirizine, ebastine, loratadine, mebhydroline, mepyramine, niaprazine, temelastine, terfenadine) were found to be non sedative.

From abstract in of:
Sedation as a characteristic discriminating among antihistamines: clinical implications
Authors: Soldatos C.R.; Dikeos D.G.
Source: European Neuropsychopharmacology, Volume 5, Number 3, September 1995, pp. 379-379(1)
http://www.ingentaconnect.com/content/els/0924977x/1995/00000005/00000003/art90679

 

[jasoncrest]

I don't care about opiate potentiation I just care about helping me get to sleep

All 1st generation antistamines (Chlorpheniramine, Diphenhydramine, Meclizine, ...) are said to be sedative.

However, most of them are not really sedative. Sedation is only one of their side-effect, but they are no sleeping pills.
With most of these antihistamines, to reach the point of sedation, you have to take high doses that cause delirium...

There are only a few antihistamines that are really good sedatives, they are prescribed or sold in many countries as sleep-aid.
Sedation is their main effect, it's not one of their side-effect.

Here are the Antihistamines I'm talking about:
-Promethazine (Phenergan)
-Alimemazine (also know as Timeprazine)
-Doxylamine
-Diphenhydramine.

These are the antihistamines that will make you sleep.
Doxylamine and Diphenhydraine are OTC everywhere.
For the Promethazine and the Alimemazine, it depends on where you live

Among these 4 medications, Alimemazine is he best for sleep purpose. here in France, it is very very commonly used as a sleeping drug

(and again, I know that all the older antihistamines, such as Chlorpheniramine,
Meclizine, etc... are said to be very sedative, but they are not)