Background: The authors present a case illustrating a mechanism leading directly to death which
is not rare but has received little attention.
Case presentation: The case was evaluated by autopsy, investigation of morphine concentration
in the blood, and clinical data. The heroin dose causing the ‚overdose‘ death of a young man who
had previously been treated a number of times for heroin addiction did not differ from his dose of
the previous day taken in the accustomed circumstances. The accustomed dose taken in a strange
environment caused fatal complications because the conditioned tolerance failed to operate. The
concentration of morphine in the blood did not exceed the level measured during earlier
Conclusion: These results are in line with the data in the literature indicating that morphine
concentrations measured in cases of drug-related death do not differ substantially from those
measured in cases where the outcome is not fatal. A knowledge of the conditioning mechanism can
contribute to prevention of fatal cases of a similar type. The harm reduction approach places great
stress on preventive intervention based on data related to drug-related death.
A case report: Pavlovian conditioning as a risk factor of heroin ‚overdose‘ death