!Inexplicable + antihistamine --- agk's diary 27 May 2026 @ 15:30 UTC --- written on GPD MicroPC in vi on the cluster as usual before driving roommate to motorcycle safety class --- Divarin asked what inexplicable experiences others had. He also stated he can't remember the difference between H1 and H2 histamine blockers. If my first story is too sad, I provided a heading for my second (on blocking histamine receptors) to aid those who wish to turn the page. 1. Not inexplicable, but providential Lonely, homeless, odd, and young, I regularly walked from my squatted apartment in an otherwise vacant building in a provincial deindustrialized city's slum district three hours to the mission where I volunteered. Volunteering got me out of the fear and loneliness of where I lived, built my skills on spreadsheets, and gave me dignity, collegial relationships, and physical safety during the time I was "at work." I had a hard couple years in my late teens and early 20s. Pretty severe police abuse (torture in custody and witnessing torture of friends, many house raids), physical complaints of homelessness (near-death stuff like dehydration til unconsciousness when dumped in deep desert by state troopers, advanced hypothermia wrapped in a tarp soaking wet in wild woods, disfiguring near-misses like bad frostbite near a truck stop and infected rope-burn blisters on both palms) -- poverty grooms one to tolerate stuff one should recoil from. There's a false consciousness went with it for me: I thought I was utterly resourceful. I lied to myself I could outwait, escape, or nurse myself back from any adversary. I'd done it before. On one of my long walks to where I volunteered, a man paced me and started in with the flattery. One part of me was entertained. I could enjoy his lies and his danger at the same time. Both fed my pride. Somehow I followed him into an abandoned two-story house across the street from where we walked, the sole survivor on a once-residential street cut off by an expressway. He just had to get something, of course. Inside the door was a man with a shotgun and other men and women smoking crack. Upstairs in a room with a broken-out window and bare mattress on the floor I disassociated to save my pride as he made me suck his cock while he smoked crack, then left (he said his lighter broke). Alone in there I tried to figure out how to escape. I'd break a long bone if I jumped from the window. I had a knife, but surprising somebody with their unexpected blood only did any good against one isolated adversary, and I was hemmed in. You can just step in a crack in your world and fall through into another. Sometimes you can't go back. A different man came through the door. "You don't really want to be doing this, do you?" he asked. Once so resourceful me just shook my head dumbly. "I didn't think so," he said. "Come on." I went with him down the stairs, through the throng perfumed with the burnt-plastic odor of crack smoke, past the gunmen at the door. A short walk away I kept going with him, suddenly so meek and obedient, and sat in the passenger seat of his work truck. I rode with him to his jobsite, where he was re- mortaring and sealing a brick wall. When my rescuer'd done enough to take another break, he asked politely if I'd like to suck his dick. I told him I did not. He was gracious. "I didn't think you would. Just wanted to be sure." Then he drove me to the place where I volunteered. I got there a half-hour early, booted up the computer, and dove into the spreadsheets. It was years later, when questioning my false self-sufficiency, that I remembered that forgotten guy. I couldn't, in fact, get out of everything I could wander into. But sometimes an angel was dispatched. Sometimes a way was made. 2. Notes on blocking histamine receptors There are, in fact, not two but four major histamine receptors, unhelpfully called H1, H2, H3, and H4. H1 = allergic response H2 = gastric acid secretion H3 = neurotransmitter release regulation H4 = immune regulation (wasn't discovered til 2000) The difference is partly just where the things are located. H2 receptors are mostly in your stomach lining, for example. A drug that gets H2s has to stay active and resident in your stomach without degrading or passing too quick. The first commercial antihistamine entered use in the 1940s. Diphenhydramine's a shotgun that targets all the histamine receptors. Generally the Benadryl brand name is diphenhydramine. Sometimes, confusing- ly, it's a newer antihistamine. Side effects are effects you don't want. Drugs are just molecules with effects, some of which you want, the rest tolerable. The second generation of anti- histamines tried to each target only one class of receptor. H1 = cetirizine (Zyrtec), loratidine (Claritin), etc suppress allergic response. Entered use in 1980s. H2 = famotidine (Pepcid) decreases stomach acid production. Entered use in 1980s. H3 = hydroxyzine (Vistaril, Atarax) counters anxiety, insomnia, and itchiness. Entered use in 1960s. No drug's a platonic ideal. The second generation are more targeted than diphenhydramine, but not perfectly selective. That's why allergy medicine can make you drowsy and part of why anxiety medicine helps with itches. An incandescent lightbulb and an electric stove element are just resistors. The first glows, but it also gives off heat. The second heats, but it also glows. Molecules are the same way. Nothing's purely an antihistamine. Diphenhydramine's also, alarmingly, anticholinergic, like atropine. Some anti-allergy H1-antagonists are similar to tricyclic anti- depressants. No human's a platonic ideal either. Any antihistamine can have paradoxical effects depending how you're wired. So your H3-antagonist anti-anxiety pill makes a small proportion of people terribly anxious. No medicine's a panacea. Too much antihistamine can give you dry mouth, heart rhythm problems, panic anxiety, and eventually very dark hallucinations (Satan scratching at your windows, involuntary visions of dismembering people you meet with a chainsaw, obsessive perseveration on cannibalism). Extended use for too long can probably cause cognitive decline and maybe eventually dementia. And you can get dependent on Pepcid. Those caveats aside: Antihistamines are nice drugs. Diphenhydramine gelcaps pierced with a safety pin and squeezed under the tongue can save a life when you need to slow the closing of the airway and buy precious literal breathing room during rapid transport, if you don't have epinepherine to counter an anaphylaxis allergic reaction. A B52 shot of diphenhydramine, haloperidol, and lorazepam is a last-resort (and arguably cruel and unusual) chemical restraint that will stop most people who have confused themselves with charging elephants. After sleep or at least rest, they can try again to be chill of their own, assisted accord. Anti-anxiety hydroxyzine isn't for everyone (some people do better, for example, with a repurposed blood pressure medicine, propanolol, to limit their heart rate below panicky rhythms), but gosh it gives a lot of my patients some relief. Diphenhydramine's cheaper than newer antihistamines. And clever folks mix second-generation anti- histamines to target a few receptors while avoiding heavy downregulation of other receptors, diphenhydr- amine's anticholinergic effects, or its effect of making some people wake up evil after the sleep it can induce. For example, I've given my share of loratidine and famotidine for non-prescription neurodermatitis treatment following a loading dose of diphenhydramine. This seems to be more or less what Divarin's wife is doing. Well, that's a little antihistamine lore for the curious.