The objective of this study was a) to compare patterns of drug use in
fatal and nonfatal overdoses and b) to find out if toxic drugs are ove
rrepresented in overdoses with fatal outcome. A total of 179 cases of
fatal overdoses in Switzerland (population 6.6 million) were compared
with 269 medically treated self-poisoners from the agglomeration of Be
rne (population 301,630). Because of frequent multiple drug use, all t
he different compounds taken singly or in combination with other drugs
were recorded and grouped according to drug types. The patterns of th
e frequencies of drugs used were remarkably similar in both groups. Th
e majority of the drugs were psychotropics (81% in fatal and 68% in no
nfatal overdose). Twenty-nine completed suicides were the result of dr
ug combinations specifically recommended by EXIT, In the remaining cas
es benzodiazepines were used most frequently in both attempted and com
pleted suicide, often in combination with other drugs or alcohol. Barb
iturates were the only drugs recorded significantly more often in fata
l overdoses (9% vs 3%). No significant difference was found for tricyc
lic antidepressants (13% vs 10%), or other types of drugs. The results
are consistent with our assumption that drugs with higher toxicity wo
uld be overrepresented in overdoses with fatal outcome. Barbiturates,
which are well known to be dangerous in overdose, were clearly associa
ted with fatal overdoses, but not tricyclic antidepressants. This, in
our view, suggests that the risk of prescribing tricyclic antidepressa
nts should not be overestimated. The frequent use of benzodiazepines i
n completed suicide, however, indicates that there are no truly safe d
rugs in overdose.