There is something I cannot figure out in the report. (My highlighting below). Aren’t these two sentences contradicting each other? If not, could someone explain to me why?
2. Toxicological examination revealed 0.12mcgs per millilitre of diphenhydramine in the commander. Diphenhydramine was also detected in samples from the handling pilot, at a level of 0.04mcgs per millilitre.
3.
The level of diphenhydramine in the commander was a therapeutic level and suggests that the drug had been taken within a few hours of his demise. The half-life of the drug is between 5-8 hours and comparable levels to those found in the commander were seen experimentally two hours after a therapeutic dose of diphenhydramine.
Technical difficulties made interpretation of the level in the handling pilot more difficult but the evidence indicated that it was highly probable that it corresponded to a therapeutic concentration of diphenhydramine.
I believe that this indicates
both pilots took the drug sometime between 12 to 24 hours before their deaths. However it must be stressed that the problem of post mortem redistribution of drugs makes the interpretation of the levels very difficult (Pounder and Jones 1990).
TG where you say “with such a tiny amount detected”, I believe 0.12 mcg/mL is not such a tiny amount. Excedrin PM that was mentioned in the report to have been found and suspected to have been taken, contains 38 mg of diphenhydramine citrate (as well as 500 mg acetaminophen <= that’s paracetamol for us UK/Aus people) per tablet, and the instruction on the package says to take two. According to one of the studies,
“A 60 mg dose intake resulted in average maximum serum concentration of 0.07 µg/ml (SD = 0.02, n = 6) at the point of 1, 2 or 3 hours”. This data was based on diphenhydramine hydrochloride, so you need to adjust it for diphenhydramine citrate. I believe diphenhydramine citrate 1.5 g is about equivalent of diphenhydramine hydrochloride 1.0 g. The recommended dose for Nytol, which is the British version of the diphenhydramine HCL based non-prescription sleeping tablet, is 2 x 25 mg tablets. So you can probably see that 0.12 or 0.04 mcg/mL isn’t such a small amount - certainly 0.12 is within the therapeutic range. It can have quite a long half life too (I understand the plasma half life to be around 3-8 hours although it varies on the individual). Anyway, what I’m trying to say is that 0.12 mcg/mL or 0.04 mcg/mL is not insignificant and that it fits in with the therapeutic level of diphenhydramine and I don’t think it would be right to write it off as being insignificant, considering the effects it can have.
Combine that with fatigue etc, it
could be a factor in impairing judgement etc.
Correct me if I’m wrong though...
P.S.
For anyone interested, CAMI’s page on diphenhydramine is here:
http://www.cami.jccbi.gov/AAM-600/To...hydramine.html
It now does have the warning -
“Warnings - may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery).” I don’t know if it was there prior to the accident.