Opinions - Antihistamines potentiating opiates reversed!

[chrisn]

My pet dragon doesn't really know much about opiates but he had an interesting experience with them last night and has a question about it.

He heard that antihistamines both alleviate side effects of and potentiate opiates so here was his timeline of drug intake. Note that the melatonin had nothing to do with the experiment, he just takes it every night and lists it here for completion purposes.

0:00 25mg diphenhydramine
0:30 10mg oxycodone + 3mg melatonin
1:00 25mg diphenhydramine
1:15 5mg oxycodone
1:30 3mg melatonin

For a total of 50mg diphenhydramine, 15mg oxycodone, and 6mg melatonin. The experience began fairly normally, Puff became relaxed, head felt heavy. Nothing was all that strong, he just relaxed and played boggle online for a while. All of a sudden his body became incredibly cold (though he didn't really feel cold) and began having uncontrollable shivers and teeth chattering. He put on a few layers of clothes and after a few minutes this went away, which was good because it was a bit unpleasant. Apart from feeling relaxed, the only way he knew the opiates were effecting him was that his face and body were pretty itchy (I guess the diphenhydramine didn't alleviate this side effect).

Now here is the interesting part. All of a sudden Puff noticed he was having open-eye visuals. If he stared at a blank white surface he would see crisscrossing checkerboard lines moving around. His ceiling looked like a flat cloud of smoke was moving around on it. All in all, these visuals reminded him of the type he has gotten on HIGH doses of diphenhydramine (doses like 450mg, nothing like this would happen at just 50mg). These visuals persisted for a while, although he didn't really notice them unless he focused on them. Occasionally he'd see a random large blob flash in the peripherals of his vision, something also characteristic of high dose diphenhydramine.

He was getting quite tired so he decided to sleep. When he turned out the lights and closed his eyes, he had mild pattern CEVs as well, with little bits of color here and there. These reminded him of weak versions of what he gets on marijuana.

Has anyone experienced anything like this? Can opiates cause visuals? To my dragon, it feels like the opiates potentiated the diphenhydramine rather than the other way around. And doubtful, but could the melatonin have had something to do with it?