Newsgroups: alt.drugs,alt.psychoactives
Subject: Re: Updated version of "Marijuana Myths"
From: (Mark Thompson)
Date: 20 Jul 93 08:13:30 GMT

> I recall an earlier article which compared the LD50's of various
> substances, and it showed that the illicit drugs are no more
> dangerous, or sometimes even less dangerous, in that respect.  I think
> another useful comparison would be of the various latencies (is that
> the correct term?) of various substances, in order to expose that the
> illicit drugs are also (supposedly) no more dangerous in this respect
> as well.
> Does anyone have such a list already compiled, or at least access to
> such information or cites?
> - Paul

                     LD50s for Various Substances
          (with ratios regarding relative safety/toxicity)
                                               Typical   "Safety Ratio"
Substance      LD50        route animal       Human Dose LD50=Doses/50Kg
-------------- ------------------------------ ---------- ----------------
LSD              46   mg/Kg  iv  mice         0.25 mg o  9200
                 16.5 mg/Kg  iv  rats                    3300
                   .3 mg/Kg  iv  rabbits                 60
Psilocybin      285   mg/Kg  iv  mice         12-20 mg o 1187 - 712
                280   mg/Kg  iv  rats                    1166 - 700
                 12.5 mg/Kg  iv  rabbit                    52 - 31
DMT             110   mg/kg im mouse          60 mg im     91
DET              28   mg/kg iv mouse          60 mg im/po  23
5-MeO-DMT       115   mg/kg ip mouse          6 mg p       958
DPT              20   mg/kg iv mouse          60 mg po     16
DIPT             26   mg/kg iv mouse          30 mg o      43
THC            1270   mg/Kg  o   rats(male)   20mg o       3175
                730   mg/Kg  o   rats(female) 20mg o       1825
                105.7 mg/Kg  iv  rats         5mg(smoked)  1057
                 42   mg/Kg (inhalation) rats 5mg(smoked)  420
Caffeine        127   mg/Kg  o  mice (male)   100-200mg o    63 - 31
                137   mg/Kg  o  mice (female)                68 - 34
                230   mg/Kg  o  hamster(male)               115 - 57
                249   mg/Kg  o  hamster(female)             124 - 62
                355   mg/Kg  o  rat(male)                   177 - 88
                247   mg/Kg  o  rat(female)                 123 - 61
                246   mg/Kg  o  rabbit(male)                123 - 61
                227   mg/Kg  o  rabbit(female)              113 - 56
Nicotine        230   mg/Kg o     mice
                  9.5 mg/Kg ip    mice         .7mg(smoked)   675
                   .3 mg/Kg iv    mice                         21
Aspirin         1100  mg/Kg o     mice           325mg o      169
                1500  mg/Kg o     rats                        230
Acetaminophen    338  mg/Kg o     mice           500mg o       33.8
                 500  mg/Kg ip    mice                         50
Vitamin A       2570  mg/Kg o     mice           10-20mg o  12850 - 6425
                1510  mg/Kg ip    mice                       7550 - 3775
Strychnine        .96 mg/Kg iv    rats           .25mg o     192
                                              (relative to 1 hit of LSD)
Succinyl Choline  .45 mg/Kg iv    mice
VX (nerve gas)  .0154 mg/Kg iv    rabbits        0 mg        none
-------------- ------------------------------ ---------- ----------------
Substance      LD50        route animal       Human Dose LD50=Doses/50Kg
                                              Typical    (safety ratio)
Substance      Reckoned Safety Ratio (Closest Available Analogy)
-------------- -------------------------------------------------
Vitamin A      9637   (mice oral:human oral 15mg)
LSD            4816   (rodents iv:human oral 0.25mg),averaged
5-MeO-DMT       958   (mice intraperitoneal:human parenteral 6mg)
Psilocybin      641   (rodents iv:human oral 16mg),averaged
THC             420   (rats inhaled:human smoked 5mg)
Aspirin         199   (rodents oral:human oral 325mg),averaged
DMT              91   (mice intramuscular:human intramuscular 60mg)
Caffeine         84   (rodents oral:human oral 150mg),averaged
Acetaminophen    34   (mice oral:human oral 500mg)
Nicotine         21   (mice iv:human smoked 0.7mg)
VX (Nerve Gas)    0   (just a hunch)
    iv = intravenous     (injected into vein)
    ip = intraperitoneal (injected into body cavity)
    im = intramuscular   (injected into muscles)
     o = oral            (swallowed or eaten)
     p = parenteral      (not by mouth / usually means 'inhaled' or 
 mg/Kg = milligrams of drug per Kilogram of body weight
    mg = milligrams of drug
 All LD50's are normalized to milligrams/Kilogram of animal's body 
 All LD50 data were found in the "The Merck Index, 11th edition".
 The "LD50" is the dose of a substance that will kill a selected
 species of experimental animal 50% of the time.
"Typical Human Dose" info is taken from various sources, including
"Burger's Medicinal Chemistry", "Journal of Psychedelic Drugs",
"The Merck Manual", "NIOSH Registry of Toxic Effects of Chemical 
cigarette packages, No-Doz bottles, etc.
The "Safety Ratio" was fabricated for the purpose of this information 
based on notions of relative toxicity expressed in various pharmacology
textbooks and in a taped lecture by Andrew Weil MD.
The "Safety Ratio" is based on the dubious assumption that a human
has the same LD50 as an experimental animal in relation to body weight.
The Typical Human Dose for "recreational" or therapeutic purposes
is expressed in milligrams and the number of those doses required
to reach the corresponding LD50 for a 50 Kilogram (110 pound) human
is computed. The assumption here is that the margin of safety for a
drug is proportional to the number of typical doses a person would have
to take in order to have a 50% chance of dropping dead were they a
giant rodent. According to this reasoning, the higher the "Safety Ratio"
is, the less toxic the drug is at normal dosages.
One might well argue that it is of questionable utility to compare toxic
responses between various species using different routes of 
Needless to say, many rodents have died for our sins.
It was later pointed out that what is called above a "safety ratio"
is roughly equivalent to the pharmacological measure known as
the "Therapeutic Index". The therapeutic index is a measure of
the toxicity of a drug relative to it's usual therapeutic dose.

The NIOSH Registry of Toxic Effects of Chemical Substances also lists
most published LD50 measurements, but does so uncritically. It's
quite useful as a point of reference.