Psychiatric comorbidity symptoms during heroin addiction treatment

Toxicological analyses carried out on a sample of workers in the period 1995-1999, with reference to Decree of the President of the Republic No. 309/90

The present article describes the experience of the Italian Air Force and the Forensic Laboratory of the Catholic University regarding the application of Article 125 of DPR 309/90. During the period 1995-2000, urine samples were examined using an immunochemical technique (KIMS) and then 222 positive samples were confirmed by GC/MS. A statistical evaluation on the kind of drug involved and on the type of user/abuser was then performed.

Article 125 of the DPR 309/90 identifies certain categories of workers that are responsible for the safety of others and who have to be controlled periodically to “ascertain the absence of drug addiction among those categories of workers with duties that present risks for the safety and health of others”.

The Institute of Forensic Medicine of the Italian Air Force (Decree of the Ministry of Defence 18-04-90 and DPR No. 566 of 18-11-1988) subjects pilots and other people working in the Air Force to programmed periodical controls to ascertain whether they are suitable for flying. The Air Force carries out these controls in its own laboratories, using immunochemical screening methods to look for traces of the main substances of abuse in urine samples.

If the samples prove positive to the tests, they are sent to the Forensic Toxicological Laboratory of the Institute of Forensic Medicine of the Sacred Heart Catholic University in Rome, where they undergo analyses to confirm the previous tests, using gas chromatography and mass spectrometry. The samples are sent to the laboratory in such a way as to guarantee that they are continuously guarded and that the privacy of the tested persons is guaranteed.

From among the examined samples, this study focused particularly on the category of pilots, which is one of the main categories included in the above mentioned Article 125 of DPR 309/90.

The Catholic University laboratory controlled approximately 0.12% of the total samples, using the gas chromatography technique. Of these, 31% proved positive to the preliminary screening and were then confirmed using the gas chromatography/mass spectrometry

During the three-year period between 1995 and 1999, the laboratory of the Italian Air Force examined 177,994 urine samples using the immunochemical technique KIMS (Kinetic Interaction of Microparticles in a Solution). The analytes and related cut-offs are presented in Table 1.

The 222 samples that proved positive to the screening were sent to the forensic toxicological laboratory to confirm this analysis using the gas chromatography and mass spectrometry. Table 1 shows the cut-offs for each analyte.

Those samples drawn by the Institute of Forensic Medicine of the Italian Air Force that proved positive to the preliminary tests were divided into two groups, which were sealed and provided with a code number to guarantee the anonymity of the tested persons. One group was then kept at the Institute of Forensic Medicine of the Italian Air Force, while the other was sent to the Institute of Forensic Medicine of the Catholic University.

All the samples from the Institute of Forensic Medicine of the Italian Air Force were placed in refrigerated containers and sent by special courier to the Institute of Forensic Medicine of the Catholic University. Each sample was sealed, provided with an identification code, and accompanied by a card requesting that the sample be analysed.

In addition to the type of analysis requested, the card also indicated any pharmacological treatment that each subject might have undergone during the period before the sample had been drawn (approximately 15 days).

The samples were preserved in the laboratory of the Catholic University at a temperature of 20°C until they were opened. The Institute of Forensic Medicine of the Italian Air Force was informed about the date when the samples were expected to be opened and the confirmation analyses carried out. This could be done even in the presence of a representative of the Institute of Forensic Medicine of the Italian Air Force .

The confirmation tests were conducted using analysis techniques that have already been validated and experimented in the Institute of Forensic Medicine (1).

In order to prepare the sample, the liquid/liquid extraction technique was used, after deuterated internal standards had been added and the extracts had been derived.

A Hewlett-Packard 5890 Model gas chromatograph was used, alongside a HP 5971A mass spectrometer which worked at an electronic impact of 70 eV in SIM mode. The chromatographic separation was carried out using a HP-5 column (12 meters x 0.2 mm i.d.) in a temperature programme.

The positive values were accompanied by the quantitative data which are always indicated in the results sent to the Institute of Forensic Medicine of the Italian Air Force, together with the cut-off value (Table 1).

Any substances other than those for which confirmation was requested were specified on the response card if they were compatible with any reported pharmacological treatment undergone before the initial test (guaranteeing the privacy of the tested persons).

Table 2 presents the number of samples examined using the immunochemical screening technique, the number of samples sent to the laboratory for confirmation tests (0.12%), and the number of confirmed positive tests (31% of the samples that were examined).

The majority of the samples that proved positive following the screening contained traces of cannabis (54%) (Figure 1). This was followed by cocaine, opioids and amphetamines, while much fewer samples contained benzodiazepine.

Figure 2 shows the distribution of the substances among the group of samples that proved positive to the KIMS technique but were not sent to the Laboratory of the Catholic University for confirmation. In this case, too, the majority of the samples contained cannabis.

Among the samples examined at the laboratory of the Catholic University, the presence of cocaine was most frequently confirmed (57%) (Figure 3) while cannabis and opiates were confirmed in a smaller percentage of the samples (35% for the cannabis and 23% for the opiates). Only 3% of the samples analysed for the presence of amphetamines proved positive for phenethylamines. In 17% of the cases sent to confirm the presence of opiates, the presence of codeine or dihydrocodeine was noted, which were compatible with the drugs that were reported in the transmission cards as having been taken prior to the preliminary test.

Regarding the type of workers that were subjected to controls, there was a predominance of males (92%) both among the samples that proved positive to the preliminary screening and among the samples confirmed by GC/MS.

As for the distribution by age and gender of the samples that proved positive to the confirmation tests (Figure 4), there was a net predominance (above all for men) of persons aged between 26 and 30 (which confirms the data revealed by the KIMS method).

As for the category of pilots that proved positive to the KIMS technique, the mostly represented age groups were, in decreasing order, 26-30, 41-50, 31-40. This trend reflects the trend that was already noted for the other categories of workers, with the exception of a slight increase in the 41-50 age group. The distribution of the presence of substances found in the urine samples is similar to that found among the other groups of workers, with a predominance of cannabis.

For all those samples that proved positive to the immunochemical screening, the category of pilots was compared with those of other workers (Figure 5). Figure 6 shows the same type of distribution for all the samples confirmed by the gas chromatographic/mass spectrometric analysis. From a comparison of Figure 5 and 6, it can be noted that approximately 20% of the pilots whose samples proved positive to the KIMS technique had actually used narcotic drugs, compared with 26% of the other categories of workers. Therefore, the two distributions do not present significantly different trends, and this allows us to reach the conclusion that the diffusion of the use of stupefying substances is not correlated with the type of work performed.

The above mentioned study statistically evaluated a wide and diversified sample with respect to work performed and age distribution. In fact, the staff subjected to control by the Italian Air Force includes both pilots and other personnel that perform various types of duties.

Our data pointed to a homogeneous diffusion of the use/abuse of stupefying substances among all the categories of workers examined. Although the percentage of positive tests it not particularly high (0.2%), nevertheless, this phenomenon should not be taken lightly, above all for those workers that are responsible for the safety of others (Article 125 of DPR 209/90).

The reported level of diffusion of the use of substances of abuse could also be lower than the real figures, since toxicological tests are always planned and the subjects to be tested informed beforehand. This could mean that occasional users might voluntarily stop taking drugs before undergoing the test. Therefore, in our opinion, it would be a good idea to constantly monitor at-risk workers, by carrying out random controls without previously informing the subjects. This is, in fact, indicated in the Italian legislation: biological samples other than urine should be used that would provide a better possibility of identifying traces of substances, compared with urine (2).

Regarding a possible cross-reactivity with the pharmacological treatment underway and the toxicological screening, our preliminary results show that it is possible to obtain false positives during immunochemical screening when the pharmacological treatment includes non steroid anti-inflammatory substances. Although this finding still has to be confirmed, it points to the need to carry out confirmation tests using more specific techniques. The majority of the samples that proved positive to the preliminary screening but that were not confirmed by the gas chromatographic/mass spectrometric analyses, contained cannabis and amphetamines. Work to identify the cases of false positive results is still underway.

1) De Giovanni N., Strano Rossi S., Fucci N., Marsili R., Chiaretti M. Protocollo operativo utilizzato per la conferma della positività di sostanze stupefacenti in campioni biologici Archivio di Medicina Legale e delle Assicurazioni – Il Fascicolo – 1996.

Nakahara Y. Hair analysis for abused and therapeutic drugs. J. Chromatogr. B. Sci. Appl. 1999, 733: 161-80.

* Istituto di Medicina Legale e delle Assicurazioni, Università Cattolica del Sacro Cuore (Institute of Forensic Medicine and Insurances, Catholic University of the Sacred Heart), Largo F. Vito, 1, 00168 Rome.

** Institute of Forensic Medicine “Aldo Di Loreto”, the Italian Air Force, Rome.

Examined substances	Cut-off
	KIMS	GC/MS
Opiates	300	50
Cocaine	300	50
Cannabis	20	15
Amphetamines	1000	200

Samples examined by the Institute of Forensic Medicine, Italian Air Force using immunochemical screening
Year	Amphetamines	Cocaine	Opiates	Cannabis	Benzodiazepines	Total
1995	9322	9322	9322	9322	0	37288
1996	7887	7887	7887	7887	0	31548
1997	7027	7027	7027	7027	259	28367
1998	11529	11529	11529	11529	221	46337
1999	8208	8208	8208	8208	1622	34454
Total	43973	43973	43973	43973	2102	177994

Samples examined by the Institute of Forensic Medicine of the Sacred Heart Catholic University
Year	Amphetamines	Cocaine	Opiates	Cannabis	Benzodiazepines	Other	Total
1995	0	6	12	25	0	0	43
1996	1	5	6	13	0	0	25
1997	4	7	2	25	0	0	38
1998	15	3	8	21	0	1	48
1999	13	9	7	36	2	1	68
TOTAL	33	30	35	120	2	2	222

Samples confirmed by GC/MS
Year	Amphetamines	Cocaine	Opiates	Cannabis	Benzodiazepines	Other	Total
1995	0	0	2	10	0	0	12
1996	1	2	0	2	0	0	5
1997	0	7	0	12	0	0	19
1998	0	3	4	7	0	1	15
1999	0	5	2	11	0	0	18
TOTAL	1	17	8	42	0	1	69