Hi Summertime, Vag, Stef, and everyone,
Like Stef have mentioned, famotidine ( Pepcid), like ranitidine ( Zantac) and the likes, are type 2 histamine receptors antagonists. There are 4 known types of histamine receptors, tagged H1, H2, H3 and H4. Each one has a specific set of functions when activated, and is blocked by specific antagonists ( see
http://en.wikipedia.org/wiki/Histamine_receptor for a chart with functions and antagonists for each of the 4 types).
When people talk about an antihistamine, without any other precision, they almost always have an anti-H1 in mind, the ones against allergy symptoms like itching, watery eyes, redness, runny nose, and so on. Technically, the anti-H2, which are mainly used for reducing stomach acidity, are also antihistamines, because they block histamine receptors, only they block the H2 type. However, they are almost exclusively referred to as anti-H2, to avoid confusion, because anti-H1, who were used long before, have always been referred to as simply "antihistamine", without the precision about the H1 type.
That being said, in some case, when people has severe allergic reactions, I have already seen a few times an allergologist prescribing an anti-H2 along with a new generation antiH1 ( as cetirizine/Reactine) in the morning coupled with an first generation anti-H1 ( as diphenydramine/Benadryl) at night, in order to get the maximum possible histamine blockage. The specificity of antagonists is not always 100% for a given receptor type, so you can get a little edge with this anti-H2 add-on.
The anti-H2, like Pepcid, may help with the irritation of the stomach as well as the nausea following alcohol abuse. However, they have no benefits for the central nervous system intoxication part.
Summertime, if you have stomach soreness along with spasms, after release, you sure could try Pepcid for the soreness aspect, since it reduces acidity ( there is not much drug interactions potential and contraindications for anti-H2 use, but check anyway with your pharmacist or another health professional if it is ok for you to use it). However, lowering acidity is only indirectly addressing the spasms issue. Here in Canada, these is a drug available without prescription called dicyclomine, which is a spasmolytic ( anti-spasms ) for the digestive tract. I have been recommending it quite often over the years, because it is a simple but effective drug for stomach spasms,and intestinal hypermotility. Again, check with your pharmacist or health professional if it is appropriate for you to use it. For more information about this drug, also known by the trade name Bentylol, see
https://en.wikipedia.org/wiki/Dicycloverine . Depending of the country you live in, availability of this drug without prescription may vary. If not available, a similar drug, Buscopan, may be available OTC as it is here as well (
http://en.wikipedia.org/wiki/Butylscopolamine , but again, be sure to check for interactions and contraindications before using it ). And, in any case, as with any new drug, start with the lowest possible dose until you know your personal reaction to it. Then a slow increase is possible, till the lowest effective dosage is found, which is a safe way to find optimal dosage.
I personally do not have stomach aches or digestive problems in my list of POIS symptoms, so I can not comment about its effectiveness or not.
Hoping this will help you get better relief in your POIS acute phase !
