Lead Poisoning Due to Adulterated Marijuana in Leipzig Indication for chelator therapy should be defined critically: In Reply

by Dr. med. Franziska P. Busse, Dr. med. Georg Martin Fiedler, Dr. med. Alexander Leichtle, Dr. med. Helmut Hentschel, Prof. Dr. med. Michael Stumvoll in volume 44/2008

It is certainly true that values in excess of HBM-II-value do not automatically result in symptoms of lead poisoning, but "there is an increased risk for adverse health effects and, consequently, an acute need for exposure reduction measures and the provision of biomedical care (advice). The HBM-II-value should thus be regarded as an intervention or action level" (1). The situation we described, where, owing to consumption of adulterated marijuana, mainly young adults were exposed to chronic substantial lead intake by inhalation, cannot be compared with occupational exposures. In our opinion, lead poisoning is present in patients with a whole blood lead level >700 µg/L (2). In children, such a concentration is regarded as a medical emergency, which requires inpatient treatment (3). Correspondents are right to point out that the indication for chelator treatment has to be defined carefully because of the possible adverse effects. In view of the particular patient clientele (drug users with poor compliance) we had to assume that without intervention and in a scenario of continued drug use, the subsequent number of cases of severe lead poisoning would be much higher. For this reason, the decision was made to also treat users whose value was "only" in excess of the HBM-II-value. Under these circumstances, the fact that the use of chelators for chronic metal poisoning is controversial in the light of current data, was not enough to make therapeutic inactivity an option. Further, the guideline of the Association of the Scientific Medical Societies in Germany does not contain any statements of the criteria for chelator therapy (4), whereas the substance monograph on lead from the Human Biomonitoring Commission of the German Federal Environment Agency does not deem chelator therapy as indicated when whole blood levels are <400 µg/L (3). To treat our patients we recommended the chelator succimer, which is well tolerated, as 2,3-dimercaptopropane-1-sulfonate (DMPS) was not available from the manufacturer for a lengthy period of time, and D-penicillamine was assessed as too dangerous for long term treatment owing to its side effect profile (risk of agranulocytosis and nephrotic syndrome).

DOI: 10.3238/arztebl.2009.0480


Dr. med. Helmut Hentschel
Gemeinsames Giftinformationszentrums (GGIZ) der Länder Mecklenburg-Vorpommern, Sachsen, Sachsen-Anhalt und Thüringen, c/o HELIOS Klinikum Erfurt
Nordhäuser Str. 74
99089 Erfurt, Germany
[e-mail]

Conflict of interest statement
The authors of all letters and of the reply declare that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.

References

1. Umweltbundesamt: Gesundheit und Umwelthygiene. HBM- und Referenzwerte (Definitionen und Tabellen). http://www.umweltbundesamt.de/gesundheit/monitor/definitionen.htm

2. Gloxhuber C: Toxikologie. 5. Aufl. Stuttgart, New York: Georg Thieme Verlag 1994; 147.

3. Kommission „Human-Biomonitoring“ des Umweltbundesamtes: Stoffmonographie Blei; Referenz- und Human-Biomonitoring-Werte (HBM). http://www.umweltdaten.de/gesundheit/monitor/pbmono.pdf

4. Leitlinien der Deutschen Gesellschaft für Arbeitsmedizin und Umweltmedizin e.V. (DGAUM): Arbeit unter Einwirkung von Blei und seinen Verbindungen. http://www.uni-duesseldorf.de/AWMF/ll/002-001.htm

5. Busse FP, Fiedler GM, Leichtle A, Hentschel H, Stumvoll M: Lead poisoning due to adulterated Marijuana in Leipzig [Bleiintoxikationen durch gestrecktes Marihuana in Leipzig]. Dtsch Arztebl Int 2008; 105: 757–62.