Method Benzocaine as a method?

[loser4ever4life]

Hey y'all, firstly, I want to thank everyone here for being such good sports. Before I came to this forum I was really worried about how I would do this and by what means. I didn't want to traumatize anyone else and wanted a "peaceful" way out. You guys have so many amazing resources! I'm currently fixated on something that hasn't really been tried before because of the ease/speed that I can get benzocaine. I went down to my local pharmacy and was shocked to see 14 mL bottles of 20% benzocaine just sitting there (which comes out to about 2800 mg per bottle). I guess as it stands my plan is to take some antiemetics before chugging two bottles since my other plan (partial suspension) just doesn't seem as appealing for some reason.

I've search the forums for this topic, of using benzocaine as a method of inducing methemoglobinemia (the same mechanism of action that SN kills you by) and the results said that the LD50 was crazy high like in 2000 mg/kg of bodyweight. However, that was in mice. In human adults, we have seen toxic and fatal outcomes in as little as 200 mg applied.

Another very important thing that I found was that toxic effects were reported in people who used the solution as intended (spray), which would mean they have a tiny amount of benzocaine compared to someone who would drink the solution or took a giant swig and washed their mouth in it?

I know the literature is scarce on this, but I just wanted to hear what other people thought of this, seems too good to be true? Also for anyone about to suggest lidocaine, benzocaine was found to produce more severe methemoglobinemia. I'm sorry if this stupid, just trying to end things sooner rather than later

 

[Kali_Yuga13]

I read about benzocaine/lidocaine awhile back. I don't know enough about the amounts to trigger lethal methemoglobinemia but I remember reading at least one pubmed report of a ctb via this method. I've also wondered why it hasn't been mentioned much here.
From Poison Control : (Keep in mind threshold for poisoning doesn't necessarily equate with fatality)
The Threshold Dose for recommending observation or any interventions ranged from 5-40 mg/kg.· The median threshold dose for recommending observation was 22 mg/kg.

 

[loser4ever4life]

I read about benzocaine/lidocaine awhile back. I don't know enough about the amounts to trigger lethal methemoglobinemia but I remember reading at least one pubmed report of a ctb via this method. I've also wondered why it hasn't been mentioned much here.
From Poison Control : (Keep in mind threshold for poisoning doesn't necessarily equate with fatality)
The Threshold Dose for recommending observation or any interventions ranged from 5-40 mg/kg.· The median threshold dose for recommending observation was 22 mg/kg.

Wow that was a great read, thanks for introducing me to that. It seems there are too many factors that have yet to be studied at the time of that study (20 years ago). Another thing that I found crazy was "a patient could be cyanotic with methemoglobinemia, yet not require treatment". You have to maintain 70% methemoglobinemia levels in order for lethality.

P450-mediated drug metabolism is just something that I just can't control for, I won't know if I rapidly metabolize this stuff ( a non responder) until I give it a shot.

Edit: Yeah after some follow up research, I found this study; doi:10.1016/j.tripleo.2010.06.011

39 year old man used 1.5 7 mL bottles of 20% benzocaine topical cream (about 10 mL total so about 2100 mg of benzocaine) and the highest his methemoglobinemia levels got were about 34%, half of what is needed. The only thing about extrapolating this case is that he did this over 8 hours but still. Yes it is a slightly different route of administration.

Every fatality associated with benzocaine appears to be either an infant (sad) or someone with lots of comorbidities (89 year old who was on deaths bed)

 

[Kali_Yuga13]

P450-mediated drug metabolism is just something that I just can't control for, I won't know if I rapidly metabolize this stuff ( a non responder) until I give it a shot.

If I were to use this route, I'd calculate the mg/kg for my weight and how many mg's per botte. Then I'd triple or quadruple it similar to the SN method and find a secondary way to potentiate it.

Accidental ODs have occurred by people simply over using the liquid or gel. Not hard to do when one's blinded with a tooth ache. It doesn't sound like one needs gallons of it or anything.

I'll have to do some more reading or maybe someone else can chime in. People are getting scared of wellness checks in the UK and one of the only SN suppliers being monitored or possibly shut down so a new method is worth looking into.

 

[loser4ever4life]

Thanks, I don't want you to spend too much time on this, I read your other post about your sister with stage 4 cancer. While I appreciate all the information you've given me, I don't want to be a reason you spend less time with her. (I know you're an adult making your own free will choices but as I'm writing this I feel like a burden, goes to show how far gone my thinking is lol).

As much as I dislike AI, I do find its ability to synthesize literature very helpful and so I will write down what I have gathered so far;

The medical solution we are working with is 20% benzocaine, meaning roughly 200 mg/mL . Bottles are small, around 14 mL, so about 2800 mg per bottle.

The main difficulty arising with this method is there is very little direct link between the specific dose (mg/kg) and resulting methemoglobinemia levels, especially in humans. Which makes accurately calculating the needed dose damn near impossible, at this point, it is guess work. While in animals the LD50 is 2,100 mg/kg, adult humans can experience symptoms from as low as 200 mg. ChatGPT explains this is due to "idiosyncratic reactions and nonlinear toxicity mechanisms"

Another problem is something that I mentioned earlier; "a patient could be cyanotic with methemoglobinemia, yet not require treatment". So onset of symptoms does not correlate with fatal levels of methemoglobinemia. Almost all scientific literature discusses overdoses, which is onset of symptoms, most of these cases do not reach the 70% of methemoglobinemia levels necessary for a lethal response. OD =/= lethal response. The only cases in which fatality occurred had too many confounding factors, either they were infants/children (immature enzyme therefore different metabolic kinetics) or comorbidities.

In response to the question "what is a fatal dose of benzocaine for a 100 kg man", ChatGPT spits out a number of "~2–5 grams" (1-2 bottles) with "5 g is likely fatal or near-fatal in average adults without immediate treatment".

I would take this with a grain of salt, when I tried to get ChatGPT to explain how it came to this number, it does not provide good enough logic imo, it could not produce case studies that really backed up what it was saying.

TLDR; We don't know enough about this drug to even approach an accurate dose at this time. It seems that so few people have actually attempted with this method that we don't know if it produces the results necessary.