Læknablaðið - 01.08.1973, Blaðsíða 19

LÆKNABLAÐIÐ
141
Hann staldrar m. a. við þá staðreynd, að
langsamlega mest af þessum lyfjum er
fengið löglega hjá læknum án þess að
nokkur virðist hafa eftirlit með ávísunum
þeirra (,,... it is a remarkable fact that
patients can continue to obtain regular
supplies of sedatives for so many years
from hospitals and general practitioners,
without anyone apparently trying to re-
duce or stop the medication"). Þetta er
sýnu alvarlegra, þar eð nú er vitað, að
svefn eftir barbítúrsýrusambönd og mörg
önnur róandi lyí og svefnlyf er engan veg-
inn eðlilegur svefn (sbr. inngangsorð). Af
lestri þessarar ritgerðar má og ljóst vera,
að barbítúrsýrusambönd eru viðurhluta-
mikil lyf, jafnvel í lækningalegum
skömmtum.
Mepróbamat var í blóði tveggja ein-
staklinga í safninu (ca. 30 og ca. 45
míkróg/ml), klórdíazepoxíð hjá einum
(1-2 míkróg/ml) og díazepam hjá tveim-
ur (ca. 0,2 og ca. 1 míkróg/ml). Sam-
kvæmt Jenis et al.22 má ætla, að magn
mepróbamats í blóði sé umfram 100
míkróg/ml við alvarlegar eitranir og um
það bil 10 míkróg/ml eftir töku stórra
lækningalegra skammta. Samkvæmt eigin
athugunum (óbirtum) er magn díazepams
í blóði eftir venjulega lækningalega
skammta oft á bilinu 0,2-0,5 míkróg/mJ,
en stígandi allt að 2,0 míkróg/ml eftir
stóra skammta. Magn klórdíazepoxíðs er
4-5 sinnum meira í blóði en magn díazep-
ams eftir töku sambærilegra skammta.
Um mat á magni klórals og amítriptýlíns
eða nortriptýlíns í blóði og þvagi skortir
okkur einhlítar heimildir.
Torkell Jóhannesson, Hrafnkell Stefánsson and Ólafur Bjarnason:
Deaths due to poisoning with barbituric acid derivatives.
From The Departments of Pharmacology (T.J., H.S.) (P.O. Box 884) and Pathology (Ó.B.)
(P.O. Box 150), The University of Iceland, Reykjavík. Iceland.
Abstract: Although barbituric acid deriva-
tives have been used for decades, very little
is actually known about the usage of these
drugs and the incidence of poisoning due to
their intake in this country. However, the
first two cases of death due to ingestion of
barbituric acid derivatives in Iceland were
reported more than 50 years ago. After hav-
ing commented on the methods used for
identification and determination of barbituric
acid derivatives in blood (thin layer chromato-
graphy and ultraviolet spectrophotometry), re-
port is given of 39 cases of death that oc-
curred during a five year period from 1966
to 1971 where ingestion of barbituric acid
derivatives, with or without simultaneous in-
take of alcohol or other drugs, was involved.
The material consisted of 24 cases where
pentobarbital was involved, 7 cases involving
aprobarbital, 4 involving amobarbital, 3
cases involving phenobr.rbita! and 1 bar-
bital. Information on the amounts in-
gested were often inaccurate. In a single
conspicuous case it was, however known
that intake of only 1,3 g of pentobar-
bital (without any consumption of alcohol
or other drugs) resulted in death. A few cases
were obvious suicides. In many cases, on the
other hand, it was difficult to decide whether
death was due to a deliberate act or was the
result of more or less inadvertent events such
as intake of greater doses than usual or
simultaneous ingestion of alcohol or other
drugs. Evaluation of case reports indicated
that many individuals had started taking drugs
subsequent to surgical operations or due to
nervous disorders. Seven persons in the
material were known for sure to be dependent
on barbituric acid derivatives. On the basis of
determination of blood levels and other re-
levant information the foilowing conclusions
were forwarded:
1. Poisoning following ingestion of pento-
barbital, aprobarbital or amobarbital
is likely to be severe if blood levels of
theso drugs are in excess of 20 microg/
ml.
2. Blood levels of pentobarbital, aprobarbital
or amobarbital in the range 10-20 microg/
ml may be accompanied by a comatose
state and result in death if adequate
treatment is not available in time.
3. Ingestion of barbituric acid derivatives in
therapeutic doses may result in death if
taken simultaneously with alcohol or
other depressant drugs in amounts that
are not lethal in itself. In this connection
emphasis is put to the fact that thera-
peutic doses of barbituric acid derivatives
may also otherwise have deleterious ef-
fects in so far as normal sleeping patterns
aro consistently disturbed following their
intake.