Diphenhydramine, (over the counter) also known as Benadryl, is an antihistamine and as such is not only used for allergies/colds but also as a sleep aide. It does have a mild anxiolytic effect. May lower blood pressure and cause irregular heartbeats. Long-term use of Benadryl often affects mental cognition, especially in the elderly. Your body does build up tolerance to it after a few weeks. There is evidence of dependence in cases of long-term heavy uses, It is a histamine H(1)R antagonist in the brain. Do not take this medicine with any other medicine that can cause sleepiness including benzos, most blood pressure medicines, ssri/snri, buspar and others. Please check for compatibility before using. This medicine has many drug interactions.
Begins working in 15 to 30 minutes
Peak levels - 2 to 2.5 hrs
Half Life – 4 to 6 hrs
Use by members for anxiety relief, brain zaps and to help sleep is too numerous to mention.
Can cause dependence with constant heavy use. Some moderate withdrawal symptoms possible.
Diphenhydramine should NOT be taken with hydroxyzine. Drugs.com
Technical information on Diphenhydramine(Benadryl)
serendipity - I found Benadryl to produce hangover effects, and cause palpitations when taken long term. Even if you wake up in the middle of the night, and can't get back to sleep, even a teeny amount (say, 15mg) can induce sleep again.
Schmb - Benadryl worked on a limited basis for me, because sometimes it makes me jittery, and that only made the zaps much worse, so just use some caution in case you are sensitive to it.
FH - One caution on benadryl. It is famous for bad reactions with other medicine so check your compatability closely. The maximum dosage of benadryl is 25 to 50 mg every 4 to 6 hours and do not surpass 300 mg in a day.
•Acetaminophen, 500 mg
•Diphenhydramine Hydrochloride, 25 mg
•Pseudoephedrine Hydrochloride, 30 mg
It contains diphenhydramine which is the active ingredient in regular Benadryl and also pseudoephedrine which is common in most cold medicines. The Diphenhydramine helps with sleep and anxiety and the pseudoephedrine helps block the action of adrenaline which produces a calming effect.
Therea re at least 75 products sold in the USA that contain diphenhydramine.
Also Kathy if you go to that thread I mentioned and did a search for brain zaps then you would find many suggestions.