Antihistamine to treat menstrual symptoms?

I was looking for something to help with my pre-menstrual back pain and water retention so I thought I’d try out Midol.
Extra Strength PMS Midol® Complete purports to help with the following issues
[ul]
[li]Irritability[/li][li]Body aches[/li][li]Bloating[/li][li]Breast tenderness[/li][li]Cramps[/li][li]Backaches[/li][li]Headaches[/li][li]Temporary water weight gain[/li][li]Tension[/li][/ul]
And contains the ingredients

Acetaminophen 500 mg
Pamabrom 25 mg
Pyrilamine maleate 15 mg

I can understand that the Acetaminophen will help treat body aches, backaches, cramps and headaches. The Pamabrom which is a diuretic should treat temporary water weight gain and bloating. So presumably the Pyrilamine maleate is the ingredient which will treat irritability, breast tenderness, and tension (whatever that means).
What perplexes me is that Pyrilamine maleate is an antihistimine. So are these symptoms caused by a histamine response? Or does this drug happen to help with these symptoms while also being an antihistammine? or, since this drug commonly causes drowsiness are they hoping that you’ll just take a nap and forget about it? Any thoughts?

Histamines are indeed released at a higher rate just before and during menses.

Whether or not antihistamines really do blunt the PMS and menstrual symptoms is debatable.

That’s interesting, I didn’t realize that. I suppose when you get all of your medical education from watching medical dramas on TV something there ends up being a few holes in your knowledge.

So does this mean that if a woman has allergies that her symptoms are worse before and during menses?

I assumed the sedative effect of the antihistamine is how Midol gets to claim their drug helps with tension and irritability.

It seems at least one individual did in this study.

Histamine metabolism during the menstrual cycle.

More study needs to be done, surely.