Method On the Diphenhydramine Overdose Suicide Method

[PaChOnCiTo]

I analyzed 36 (n = 42) case reports of diphenhydramine (DPH) overdose. Here's what I found:

83% (n = 35) lived; 100% (n = 35) received medical assistance; 71% (n = 25) were monointoxications.
17% (n = 7) died; 86% (n = 6) received medical assistance; 57% (n = 4) were monointoxications.

The average overall dose was 5.5568 g.
The average non-lethal dose was 5.4461 g.
The average lethal dose was 6.1107 g (7.1 g in monointoxications).

The average overall dose by weight was 60.6144 mg/kg.
The average non-lethal dose by weight was 59.4412 mg/kg.
The average lethal dose by weight was 70 mg/kg in monointoxications.

LDmin is 10.1 mg/kg.
A massive ingestion is defined as a dose by weight of 20 mg/kg.
LCmin is 5 micrograms/mL.

A dose in the range of 1-1.5 g is associated with severe symptoms (seizures, coma, and death). A dose >1.5 g is associated with increased risk/frequency of severe symptoms. (Valid for monointoxications and no preexisting risk factors).

The ratio of orally ingested dose, in grams, to peak serum concentration, in micrograms/mL, is almost 1:1. 0.05 g yield 0.0822 +- 0.0315 micrograms/mL. 0.9 g yield 0.977 micrograms/mL. 1.2 g yield 1.32 micrograms/mL.

The average time to reach peak serum concentration after ingestion is 2 hours 9 minutes.

The average bioavailability is 56.25%.

A personal lethal dose must be equal to or greater than the reference values. To be sure, a personal lethal dose should at least double the reference values, if/when possible. As an example, let's see if my personal lethal dose satisfies this requirement:

Reference values (monointoxication; 60 kg)

14.2 g (2x average lethal dose).
140 mg/kg = 8.4 g (2x average lethal dose by weight).
20.2 mg/kg = 1.212 g (2x LDmin).
40 mg/kg = 2.4 g (2x massive ingestion).
10 micrograms/mL = 9.8619-6.0827-4.3975 g; 9.2118 g; 9.0909 g (2x LCmin).
>3 g (2x dose associated with increased risk/frequency of severe symptoms).

My personal lethal dose of 15 g DPH HCl does satisfy the above-stated requirement. This means that, if ingested, death is the most likely outcome. For this to be the case, though, the time it takes to reach peak serum concentration must elapse without disturbances (medical assistance). To be sure, just like with the reference values, this time should be at least doubled (4 hours 18 minutes). Although a 24-hour pre-ingestion fast to avoid emesis (vomiting) makes intuitive sense, I have no evidence to support its implementation. I also don't know how this procedure would affect bioavailability, if at all.

I won't be swallowing 600 25 mg or 300 50 mg tablets/softgels. I was able to find 50 mg hard capsules, so I have access to pure DPH HCl in powder form. I consider this to be the ideal scenario, since swallowing the aforementioned quantity of tablets/softgels would typically involve drinking a very large amount of water, increasing the likelihood of emesis. DPH powder can be easily obtained from the hard capsules, by disassembling them, allowing for direct dissolution in water, and perhaps enhanced bioavailability.

I chose this method because it is OTC where I live and relatively inexpensive.



I think that is all.

 

[MiMif]

Dph is also my overdose of choice currently...so your saying rather then taking the tablets it's best to crush them into powder before consuming them? Would you drink it with water? And you need 5 grams for a lethal dose?

 

[PaChOnCiTo]

Dph is also my overdose of choice currently...so your saying rather then taking the tablets it's best to crush them into powder before consuming them? Would you drink it with water? And you need 5 grams for a lethal dose?

I think crushing the tablets into powder and trying to dissolve it in water would be better than trying to swallow the tablets whole, assuming this would allow you to drink less water overall.

I wouldn't try this with anything other than water.

There's no "officially" established lethal dose. Best we have is estimates based on body weight and lethal concentrations based on case reports. Lowest dose that caused death, that I could find, was 1.25-2.5 g. I wouldn't risk it, though. That's why I said to double the reference values.

These calculations were made for monointoxication. I don't know about polydrug overdose. Too many variables.

 

[PaChOnCiTo]

Something funny happened. Each hard capsule was supposed to contain 50 mg DPH HCl. Instead, it appears they contain 240 mg (4.8x) each, roughly. 15 packs x 20 capsules x 50 mg = 15,000 mg = 15 g. I ended up with ~72 g (380%+). I panicked when I was disassembling the capsules, seeing the sheer amount of powder I was obtaining. "No way this is 15 g." No way indeed. Happy accident I guess. Plenty backup. Terrifying for public health. Anyway, that's what the 300 hard capsules looked like. And that's the ~72 g DPH HCl I got from them, in a jar.



Why do people keep saying DPH OD is not a method? I'm here (not for very long) to prove otherwise. And I think I have the evidence to do so. Please reply with doubts/comments.