An antihistamine, primarily used to reduce mucus secretion (e.g., clear up stuffy nose) or allergic inflamation (e.g., make bug bites stop itching). It also has sedative effects and care should be taken when combining with alcohol or other depressants.

Diphenhydramine is commonly known in the U.S. as Benadryl™, which is the name used by the pharmaceutical company Warner-Lambert. It is sold over the counter in tablets or capsules.

Note that while normally a dose of Benadryl can put out a horse in about 30 seconds (very similar to NyQuil), it has an odd side effect on small children and small animals (sometimes). It causes them to be very very hyper.

Diphenhydramine, a sedative, is also the active ingredient in numerous sleep aids such as Sominex.

You might want to consider this before you take Benadryl in the mornings to prevent allergies. Prescription antihistamines such as Claritin or the much-less-expensive-though-equally-effective Allegra are usually a better choice.

Antivertigo agent

Common Dosage: 25 to 50 milligrams (mg) every four to six hours

May interact with:

Clarithromycin (e.g., Biaxin)
Erythromycin(e.g., E-Mycin)
Itraconazole(e.g., Sporanox)
Ketoconazole (e.g., Nizoral)
Bepridil (e.g., Vascor)
Disopyramide (e.g., Norpace)
Maprotiline (e.g., Ludiomil)
Pimozide (e.g., Orap)
Procainamide (e.g., Pronestyl)
Quinidine (e.g., Quinaglute Dura-tabs)
Central nervous system (CNS) depressants
HIV-protease inhibitors
Monoamine oxidase (MAO) inhibitors

This drug is also used recreationally. Due to similar chemical structure, it has the exact same effects as of Dimenhydrinate (also known as Dramamine) save that it is almost twice as strong, and causes a greater sedative effect. Under this drug you will likely feel these effects for about 3-7 hours (a common dosage is 8 pills or so):

  • A body high, so strong as to render you clumsy
  • A very strong drowsiness effect- It is a sedative
  • Intense Auditory and Visual Hallucinations - You may not even realize you are seeing things
  • Due to the high dose of antihistamine, your mucus membranes will be almost completely dried out, causing a dry throat pain.

Alternatively, one can go real hardcore and ingest upwards of 14-20 pills. DON'T DO THIS. EVER. Every one I have talked to who has done this, assuming they actually stay awake for the trip, have these types of effects:

  • All the effects of a lighter dose for about the first 2 hours, with gradual but potent intensification over time.
  • After about 3-5 hours, expect to black out and not remember anything for about the next 12 hours. If you (foolishly) popped more than 18 pills, this blackout could occur for even a few days. You may remember bits and pieces, but it will mostly be a potent, vague drunken-like blur.
  • During this period of blackout, you are likely to have a psychotic breakout. Needless to say, this may disrupt the wellness of your psyche permanently.
  • You are very likely to wake up in a hospital. Even if you don't physically hurt yourself (from the drug itself or from doing something dangerous while on it), your peers may be inclined to admit you due to your irrational state.

This is not a very safe recreational drug. There are some cases of allergic reaction to antihistamines such as diphenhydramine that only seem to occur at fairly high thresholds. In other words, even if you take this drug regularly for medical purposes, there could be a magic number of pills that induce anaphylactic shock.

Regardless of allergic reaction, high doses of antihistamines can cause very ugly effects, including difficulty breathing, seizures (rarely), nausea, extreme redness of eyes, etc. Also, expect a nasty hangover for a day at least.

Notes on diphenhydramine as a sleep aid:

There are two major points to remember when dealing with using benadryl to get to sleep. First, it is extremely potent, and a fairly small dose will knock out just about any "normal" case of insomnia. The second point is, for all of that, it is not a good way to get to sleep, even on an "emergency" basis. Even on an emergency basis, usage is never a good thing.

If you read the above writeup on the "recreational " use of benadryl, you will see some of the reasons why it is not a good idea to play around with this substance. Of course, at the doses used to cause sleep, it is not causing 24 hour long blackouts, but I have experienced some hypnogogic hallucinations while under the influence. A metallic taste in the mouth and difficulty in micturation can also be expected. Of course, for the person who really needs to sleep, sucking on some cast iron lozenges is a small price to pay. But this comes to the Catch-22 of diphendhydramine. Whatever you gain in time spent sleeping from the effects, you lose from suffering the weird hangover the next day. Four hours of straight sleep are probably going to be about as refreshing as 8 hours of drugged sleep.

If, for whatever reason, you choose to use Diphenhydramine as an emergency sleep aid (and that is about all it is good for, since it developes a tolerance quickly), there are a few things to remember.
First, it doesn't make you sleepy, it makes you drowsy. If you are already fairly well caught up on sleep, and haven't been awake for very long, there is a good chance that it will leave you droopy limbed lolling insensitate, without actually causing you to sleep. After a few hours, the effects may wear off, and you will still not be asleep.
Second, be careful with the dosage. It has a way of creeping up on you slowly. It may take a long time to onset at all, and then once it does, increase very quickly. Don't start popping pills if it doesn't work at first.
Third, it does not give especially respectful sleep. I've noticed some rather odd nightmares under the influence. If you are in an unfamiliar situation, you may be disoriented when you wake up. Prepare for this.

I would suggest other remedies for sleeplessness, such as hot cocoa with honey and soy milk, and apologizing to the people you offended.

I feel it necessary to disagree with ultima's writeup. Of course, as usual when drugs are involved, your mileage may vary, and my sources are simply my own experiences, those of a few close friends, and everything on the internet that I could get my grubby little paws on. So, this is in no way definitive, but just thought it was worth contributing a writeup to a node I actually consider myself somewhat knowledgeable about (It was necessary so I could argue intelligibly with "Getting high on Benadryl! I say, that is absurd!")

Also, it is worth noting the dosages I was working with, since this is a strange drug that behaves differently in various situations and people and amounts. I was taking around 800 mg (32 pills) per diphenhydramine experience, and also taking a quantity of pseudoephedrine to combat drowsiness. I was approximately 180 pounds and male.

One of the benefits of diphenhydramine as a deliriant in comparison to the tropane alkaloid plants is that precise dosing is simple, as opposed to a guess of how many leaves or berries or seeds are necessary to achieve the desired effects. A miscalculation with belladonna can quite easily result in death or a trip to the hospital.

I found the best way to take it is right before bed (you can omit the pseudoephedrine then), mostly just because you wake up, and have passed through the state where coordination is significantly impaired. And I find it more enjoyable and immersive to wake up hallucinating.

The primary characteristic of the trip as I experienced was attempting to interact with aspects of reality that did not exist. The most amusing example was imagining an adventure to pick up a friend and go shopping, all the while never moving from a parking lot. This was the only constant in the trip that I noticed. There was no mood change, time distortion, just imaginings. There was a faint, but definite spiritual quality that I began experiencing midway through the day, that drove me to go for a walk in the woods(with my sitter, of course), which was a very nice experience. In contrast to most of what I've read about deliriants, I found that I remembered all or most of my trips in their entirety.

I have had no health problems (that were noticeable like ultima noded about anyway) or mental problems, but as usual, there is almost certainly some long term negative health effects that are related to long-term use of recreational doses, and perhaps prolonged medical use, or even one recreational dose.

Looking back, this was perhaps the best drug I ever used recreationally. It is an experience. However, the key is preparation and respect, since that is key to all drugs. Don't take drugs when you have responsibilities you need to take care of the next day. Have someone around that you can reality check with and to take care for you if the experience becomes too intense. If you smoke cigarettes, I find it to be very soothing, since (I believe) diphenhydramine antagonises the acetylcholine receptors which are the same receptors that nicotine agonises. Primarily, what I'm saying is use common sense. Some people prefer dimenhydrinate but that's mostly a matter of taste, and I find it better to take the diphenhydramine because the pills are smaller and less are involved.

If you feel comfortable altering your state of consciousness with chemicals, it might be worth it to you to do some research and decide if it's something you would be interested in experiencing. I advise experiencing it at least once in your life, it's a beast that I've only come across once.

Happy Trails.

Damn, I really just wanted to type Benadryl as opposed to diphenhydramine. Saying it gets old fast.

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