Habilitation Dr. Daunderer - Klinische Erfahrungen
mit Antidot 4-DMAP
Table of Contents
Introduction
Chemical and Physical Properties
Quantitative Composition of the Injection Solution
Information about the Analytics
Quality Control
Toxicological Properties
Teratogenic
Properties
Pharmacological Properties
Dosage and Mode of Application
Compatibility
Clinical
Examinations
Pharmacokinetics
4-DMAP INTRODUCTION
This documentation includes the description of 4-DMAP,
a preparation for the treatment of poisonings with cyanides, hydrocyanic acid
and nitriles, also possibly of poisonings with
hydrogen sulphide.
The experimental examinations with animals and the
basic clinical experiments were conducted almost exclusively at the Pharmakologisches Institut der Universität München (Pharmacological Institute of the
treatment of
cyanide poisoning for more than 10 years.
The results of relevant examinations have been recorded in numerous
publications and scientific reports for the "Sanitäts-Lehr-
und Arbeitsgruppe ABC-Schutz
("Medical, Eductional and Working Group ABC
Protection").
In the following, 4-DMAP is always understood as
4-Dimethylamino-phenol hydrochloride.
Chemical and Physical Properties
4-DMAP forms snow-white crystals which are
very readily soluble in water and which
melt at 345. ]°C.
4-DMAP is rapidly oxidized in an aqueous solution giving rise to
intensively brown to blackish-brown coloured derivatives due to polycondensation of the corresponding quinone.
The determination of the decomposition kinetics of
4-DMAP solutions
at 20°C and a pH
value of 5.0, the Standard of the active substance drops from 100 % to 96.8 %
in the course of 8.2 years. In this respect, a 4-DMAP solution can be described
äs remarkably stable.
See also:
C. Bannert and K. Weger: 4-Dimethylaminophenol für intramuskuläre
des Sanitäts- und Gesundheitswesens der Bundeswehr München 1973 (Academy of the Sanitary and Public Health
Service of the Federal Army Munich 1973)
Quantitative Composition of the Injection Solution
5 ml contain:
2500 mg
4-Dimethylaminophenol hydrochloride 2,5 mg
Sodium-disulfite, ^28205 0,5 mg Na EDTA
£1
pH = 4.7, reached with app. 10 mg Sodium-hydrogencarbonate
A patent for the procedure of the preparation of
stable aqueous 4-DMAP solutions has been applied for at the Bundespatentamt (Federal Patent Office) in
Aqueous solutions of 4-DMAP give, in the
presence of oxygen and at pH values above 3.0, intensive discolourations
within 12 hours. The rate of oxidationprocesses
hereby taking place and which are followed by colour producing polymerisation processes, is determined by the degree of dissociation of
the proton of the phenolic OH-group according to the
following equation:
Upon raising the pH value to above 3,0,
preferably above 5,0, which is necessary
for application technical reasons, the oxidation of 4-DMAP in aqueous solution
is already effected by traces of oxygen dissolved.
The complete elimination of oxygen by use of inert gas
while filling 4-DMAP solutions into ampoules is ensured only by the addition of
effective antioxidant agents because of the subsequent contact with air which
is technically only difficult to avoid during the form-turning of the ampoules
or phials. This aspect forms the basis
of the aforesaid patent application.
Information about the Analytics:
1. 4-DMAP
Pure Substance Determined are:
a) Melting point
b) Content: by
titration
by elementary
analysis
c) I. R.
-spectrum
d) Chromatogram
e) Drying loss
f) Sulphate ash
g) Heavy metals
2. 4-DMAP
Ampoules
a) Identity
b) pH value
c) Drying residue
In case of poisonings with hydrocyanic acid, cyanides and nitriles, also possibly in case of poisonings with hydrogen
sulphide.
Quality Control:
1. Sterility
The quality controls of 4-DMAP are executed according
to the Standards and terms of the DAB VII - Deutsches Arzneibuch VII (German
Pharma-copoeia VII).
The examination of the sterility is carried out with
4 filling units (ampoules) at the beginning of the
sterilising filtration, 4 filling units in the middle of the sterilising
filtration and 4 filling units at the end of the sterilising filtration.
In detail, the procedure of the proof of sterility is
as follows:
10-15 ml of Standard-I-nutrient
bouillon (Merck, Art. No.7882) is incubated with 3 ml of 4-DMAP
feed, to be examined, at 37°C for 6 days. Any turbidity must not occur.
Furthermore, a plate test is carried out äs a control:
a) Standard-I-N-agar for the detection of particular
germs
b) Sabouraud-glucose 2 %
agar for the growing and Isolation of pathogenic fungi and yeasts and
c) Thioglycolate bouillon
according to USP XVIII (Merck, Art.No.
8190 and 8191) for the test on anaerobic microorganisms
is poured into
sterile Petri dishes. The 4-DMAP feed to
be examined is spread lege artis
into these culture media.
The culture media are incubated
a) at 37°C and
b) at 25°C for 6 days.
According to the observations made so far, an aqueous
solution of 4-DMAP proves itself to be autosterile in
a therapeutically designated concentration.
2 . Absence of Pyrogens
For toxicological reasons, the execution of the pyrogenic test on rabbits according to the regulations of
the DAB VII - Deutsches Arzneibuch VII (German
Pharmacopoeia VII) cannot be realized with an adequate volume
of the 4-DMAP solution.
Toxicological Properties:
1. Acute toxicity:
According to the investigations of N. Weger et al. , the
LD for
0 U
dogs is 26 mg/kg of
animal, whereby about 85 % of ferrihaemoglobin (methaemoglobin)
is formed. The animals die of anoxia
because only 15 % of the haemoglobin is available for the transport of oxygen.
With a ferrihaemoglobin content under 80 % of the
total haemoglobin, all the animals survive.
The therapeutical dose of
3-5 mg of 4-DMAP/kg of human being oxidizes only 30-50 % of the haemoglobin to ferri-haemoglobin.
2. Chronic
toxicity:
With regard to the application of 4-DMAP according to
regulations, the examination of the active substance under the conditions of
the chronic toxicity is not necessary. Despite this, in the dog experiment, 3 mg of
4-DMAP/kg of animal was intravenously applied twice a week during a period of
13 weeks. This dose oxidizes 35 % of the
haemoglobin, but does not cause changes, either macroscopically or
microscopically, on the liver, spieen, kidney, heart,
on the blood count or transaminases and creatinine.
See also:
M. Kiese, L. Scinicz, N.
Thiel and N. Weger: Wirkung des 4-Dimethyl-
aminophenols und 4-Aminophenols auf Organe von Hunden und Ratten; scientific report from the Pharmakologische
Institut der Universität München 1973 (Pharmacological
Institute of the University of Munich
1973).
Teratogenic
Properties:
Examinations with 4-DMAP for effects which are
detrimental to the cells of propagation have not been carried out in view of
the range of indications of this active substance.
Pharmacological Properties:
The detoxification of cyanides, hydrocyanic acid and nitriles proceeds according to the following scheme:
Ist Step:
2+ 3+ 4-DMAP + haemoglobin (Fe -O )
———> ferrihaemoglobin (Fe
)
&
2nd Step:
3+ CN + ferrihaemoglobin
(Fe ) N s ferrihaemoglobin-CN-
complex
(Fe3+CN") 3rd Step:
CN + sodium thiosulphate —————> thiocyanate (SCN )
^ rhodanase
For the therapy of poisonings with cyanides,
hydrocyanic acid and nitriles, about 30 % of the
haemoglobin must be oxidized to ferrihaemoglobin. After an intravenous application of approx. 3 mg of 4-DMAP/kg of body weight, the
semi-maximum concentration of ferrihaemoglobin is
reached within one minute, the maximum concentration after 5-10 minutes.
The physiological reduction of ferrihaemoglobin
to haemoglobin can be observed already after 30 minutes, 10 % of the total haemoglobin still
being present äs ferrihaemoglobin
in the human being after approx. 4 hours after the application.
In case of an overdosage of
4-DMAP, the reduction process can be shortened to 30-15 minutes by an intravenous
application of 2-4 mg of o-toluidine blue/ kg of body
weight.
After an intravenous injection of 4-DMAP, disorders, either in the
coronary circulation System or in the carbohydrate and protein metabolism, are
not observed. Heinz inner bodies are not found.
The activity of the transaminases remains
unchanged.
After the conversion of the haemoglobin-cyanide
complex into the ferrihaemoglobin-cyanide complex by
4-DMAP, the detoxification of the cytochrome oxidase blocked by the cyanide must be completed by high
doses of sodium thiosulphate. That means, in a second step of the therapy,
the cyanide is converted into the' relatively non-toxic thiocyanate
with the help of the endogenic rhodanase. This secondary detoxification process is
decisively accelerated by intravenous administrations of 50-100 mg of sodium thiosulphate/kg of body weight. Thiocyanate is
excreted up to 80 % in the urine. Ferrihaemoglobin is
physio-logically reduced to haemoglobin.
See also:
N. Weger: Therapie der Blausäurevergiftung durch Ferrihämoglobin-bildung; Habilitations-Thesis
from the Pharmakologische
Institut der Universität München 1969 (Pharmacological
Institute of the University Munich
1969).
N. Weger: Aminophenole als Blausäureantidote; Arch.
Toxikol., 2A (1968), 49-50.
P. Eyer, M. Kiese, G. Lipowsky and N. Weger: Reactions of 4-Dimethyl-aminophenol with Hemoglobin, and autoxidation of
4-Dimethylamino-phenol; Chem.-Biol. Interactions, Q_ (1974), 41-59.
M. Kiese, R.
Klimmek,
L. Szinicz
and N. Weger: Wirkung von 4-Dimethyl-aminophenol und Co-Histidin auf Atmung,
Kreislauf und verschiedene Parameter des Blutes bei Beagle Hunden nach
akuter CyanidVergiftung; Scientific
Report from the
Pharmakologische Institut der Universität München 1974 (Pharmacological
Institute of the University of Munich
1974).
M. Kiese, R.
Klimmek, L. Szinicz
and N. Weger: Wirkung von 4-Dimethyl-aminophenol auf
Atmung, Kreislauf und verschiedene Parameter des Blutes bei Beagle Hunden; Scientific Report from the Pharmakologische Institut der Universität München 1974
(Pharmacological Institute of the
University of Munich 1974).
Dosage and Mode of Application:
After the diagnosis of a poisoning with hydrocyanic
acid, cyanides
or nitriles,
3-4 mg of 4-DMAP/kg of body weight is immediately injected intravenously
within 30 seconds, that means: For an adult,
approximately l ampoule of 5 ml containing 250 mg of active
substance.
Subsequently, 100-500 mg of sodium thiosulphate/kg of body weight is infused through the same
needle.
See also:
N. Weger: Cyanidvergiftung und
Therapie;
Wehrmed. Monats sehr. , 19 (1975), 6-11.
M. Daunderer, H.
Theml and N. Weger:
Behandlung der Blausäurevergiftung mit 4-Dimethylaminophenol (4-DMAP); Med.Klin. , 69 (1974),
1626-1631
Compatibility:
In the investigations with the animal äs well äs in the application in
man, 4-DMAP does not show any effect on the blood pressure and the flow
velocity in the blood vessels.
Wenn applied
according to the regulations, no other Symptoms occured
besides the cyanosis (formation of ferrihaemoglobin)
to be expected.
The effect of 4-DMAP on newbornes
and infants has not been investigated. Since the methaemoglobin
reductase is not yet fully effective in newborns,
there is the danger of a long lasting methaemoglobinemia.
4-DMAP does not cause any disorders in the
carbohydrate and protein metabolism. The antidote does not form Heinz inner
bodies and reacts inert in relation to the activity of the transaminases.
In experiments with dogs and rats, it was shown that a
dose of 30 mg of 4-DMAP/kg of animal does not cause pathological changes in the
kidney.
See also:
H. Offterdinger and N.
Weger: Kreislauf und Atmung bei Blausäurevergiftung
und Therapie mit Ferrihämoglobinbildnern und
Kobaltverbindungen; Naunyn-Schmiedebergs Arch. Pharmak. , 264 (1969), 289.
N. Weger: Therapie der Blausäure Vergiftung; Med. Monatsschr., _23
(1969), 436-440.
M. Kiese, L.
Szinicz, N.
Thiel and N. Weger: Wirkung des 4-Dimethyl-
aminophenols und 4-Aminophenols auf Organe von Hunden und Ratten; scientific report from the Pharmakologische
Institut der Universität München 1973 (Pharmacological
Institute of the University of Munich
1973).
Clinical Examinations:
Because the extent of action of 4-DMAP regarding the stoichiometric relations between the dose and the oxidative
conversion of haemoglobin to ferrihaemoglobin is
clarified in detail, and, on the other hand, because the detoxifying effect of ferrihaemoglobin on the cyanide-haemoglobin complex is also
very well known, the therapeutic scope of action of 4-DMAP, when applied
according to the regulations, can be exactly adjusted on this basis without
hesitation. In this respect, clinical examinations are not necessary in
case of provoked cyanide, hydrocyanic acid of nitrile
poisonings, besides the fact that clinical experiments äs
defined in the regulations of the AMG - Arzneimittelgesetz
(law governing the manufacture and prescription of medicines), under
consideration of serious ethical aspects,
cannot be realized.
See also:
M. Daunderer,
H. Theml and N. Weger:
Behandlung der Blausäurevergiftung mit 4-Dimethylaminophenol (4-DMAP) Med. Klin.,
_69 (1974) 1616-1631
M. Kiese,
J.G. Schöber
and N. Weger: Versuche am Menschen zur Kinetik der Ferrihämoglobinbildung durch Aminophenole
und Nitrit; Naunyn-Schmiedebergs Arch. Pharmak., 260
(1968), 152.
M. Kiese, N. Weger: The Treatment of
Experimental Cyanide Poisoning
by Hemiglobin Formation; Archiv für Toxikologie, 2l_ (1965), 89-100.
M. Kiese
and N. Weger: Hämiglobinbildung
zur Behandlung der Cyanid-
Vergiftung; Naunyn-Schmiedebergs Arch.
Pharmak.,
250 (1965), 263,
M. Kiese, N. Weger: Formation of Ferrihaemoglobin with Aminophenole
in the Human for the Treatment of Cyanide Poisoning; Europ. J. Pharmacology, 7 (1969),
97-105.
Pharmacokinetics:
4-DMAP is excreted through the kidneys. In the average, 16 % of a dose administered intravenously is
eliminated with the urine within 8 hours.
The following products of metabolism were detected äs metabolites by means of radioactively marked 4-DMAP i
4-Methylaminophenol, quinone,
hydroquinone, formaldehyde, dimethylamine, and a blue
äs well äs a yellow pigment
of un-known constitution.
See also:
W. Lörcher: Optimale
Konzentration von Ferrihämoglobin zur Behandlung
der
Blausäurevergiftung; Inaugural-Dissertation - Tierärztliche Hochschule der
Ludwig-Maximilians-Universität München 1973 (Veterinary
Faculty of the
Ludwig-Maximilian University of Munich 1973).