Drug analysis of residual content of used syringes: A new approach for improving knowledge of injected drugs and drug user practices

Detection of drugs and hepatitis C virus in used syringes from a needle exchange in Gothenburg, Sweden

People who inject drugs (PWID) are exposed to serious health risks such as lethal overdoses, addiction and infections. The patterns of drug use and the prevalence of hepatitis C virus (HCV) infection vary greatly between and even within countries. Data on drugs used for injection are important to inform PWID of risks and adapt healthcare. This study aimed to determine which substances are injected in Gothenburg, Sweden, and estimate the risk of HCV transmission. A total of 150 syringes handed in at the needle and syringe exchange program (NEP) in Gothenburg over a week in November 2021 were analysed for drug content using liquid chromatography coupled with high-resolution mass spectrometry. Using a dose-adjusted comparison, the main drug(s) injected was distinguished from the impurities in the syringes containing several drugs. HCV RNA was quantified by real-time PCR in an additional set of 150 syringes. Drugs were detected in >99% of analysed syringes, and the most common drugs were amphetamine (81%), followed by buprenorphine (8.0%), heroin (6.7%) and alprazolam (4.6%). Less common findings were testosterone (2.7%), methylphenidate (2.0%), MDMA (0.7%), trenbolone (0.7%) and zopiclone (0.7%). Eleven syringes (7.3%) contained more than one drug. HCV RNA was detected in 13% of the syringes, and one in 10 contained enough to potentially transmit an infection. This study underlines the importance of access to NEPs for PWID to reduce the risks associated with drug injection.

A snapshot of injecting drug consumption from the analysis of used syringes within the Medically Supervised Injecting Centre in Sydney, Australia

INTRODUCTION

The administration of illicit drugs by injection is associated with considerable harm, including an increased risk of overdose. The chemical analysis of used syringes can enhance knowledge on injecting drug consumption beyond traditional data sources (self-report surveys). This additional information may be useful during significant global events like the COVID-19 pandemic. This study aimed to examine a snapshot of the drugs injected at the Medically Supervised Injecting Centre (MSIC) in Sydney, Australia, in 2019-2020.

METHODS

Used syringes were collected from MSIC across three periods throughout 2019 and 2020 (February 2019, March-April 2020 and June-September 2020). Drug residues were extracted from used syringes using methanol before detection by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. The chemical analysis results were compared to self-report data obtained from MSIC clients.

RESULTS

Heroin (46-53%), methamphetamine (24-34%) and pharmaceutical opioids (15-27%) were the most common drug residues detected. The chemically detected drugs had declining coherence with the drugs self-reported by MSIC clients across the time periods examined.

DISCUSSION AND CONCLUSIONS

There was no significant change in the drugs injected (heroin, methamphetamine and pharmaceutical opioids) across the three periods collected throughout varying COVID-19 lockdown restrictions. Changes in the frequency of other drugs injected and discrepancies between chemical analysis and self-report were potentially related to regulatory changes, degradation or misinformed sales. Routine chemical analysis of used syringes has provided an alternative information source to promote awareness of current drug trends and aid harm reduction.

[Which psychoactives substances are found in used syringes?]

OBJECTIVE

The aim of this study is to analyze the residual content of used syringes.

METHODS

Used syringes were collected in March 2014 at 9 sites in Marseille (automatic injection kit dispensers, streets, drug-user risk reduction centers [Centres d'accueil et d'accompagnement à la réduction de risques pour usagers de drogues [CAARUD]). Several substances (n=28) were investigated using liquid chromatography and mass spectrometry method.

RESULTS

On average, 2±1 substances in each syringe were found among 254 syringes analyzed. The most detected substances were cocaine, buprenorphine, methylphenidate and cathinones (in 57 %, 56 %, 39 % and 19 % of the syringes respectively). Heroin and morphine were found in 10 % of the syringes.

DISCUSSION-CONCLUSION

This study helps define the main substances consumed by injection drugs users. It highlighted differencies in used substances according to neighborhood and site of collection and thus help to adjust prevention and harm reduction strategies.

A culturally appropriate method for validating self-reported drug administration among indigenous people who use injection drugs

Compared with other racial/ethnic groups in the United States (US), American Indians/Alaska Natives have one of the fastest climbing rates of drug overdose deaths involving stimulants. Validating the substances self-reported by Indigenous people who use injection drugs (IPWIDs) can present logistical and cultural challenges. While the collection of biospecimens (e.g., urine, blood, hair follicle) can be one way to cross-validate the substances self-reported by IPWIDs, the collection of biospecimens has been historically problematic when conducting substance use research with Indigenous North Americans. In our National Institutes of Health (NIH)-supported pilot research conducted with IPWIDs, we have documented low willingness to provide a biospecimen to a research team. This article demonstrates an alternative method for validating self-reported substances injected by IPWIDs that does not require the extraction of biospecimens from Indigenous bodies and spaces. The method described includes:•Collecting used, unwashed syringes from IPWIDs at the time of behavioral assessment,•Sampling the used syringe by washing the syringe needle/barrel with methanol,•Analyzing the samples with gas chromatography mass spectrometry (GC-MS) and liquid chromatography coupled to triple-quadrupole mass spectrometry (LC-QQQ-MS). This method offers a more culturally appropriate alternative to validate substances self-reported by IPWIDs during behavioral assessments.

Which illicit drugs are injected in Oslo? A study based on analysis of drug residues in used injection equipment and self-reported information

BACKGROUND

People who inject drugs (PWID) have a high risk of premature death due to fatal overdoses. Newly emerged fentanyls, much more potent than heroin and other opioids, may increase this risk further. Therefore, precise information on injected drugs is critical to improving prevention strategies.

AIMS

This study aimed to analyse drug residues in used injection equipment in order to determine drug and drug combinations and compare and complement findings with self-reported information.

METHODS

Used syringes and needles (n=766) were collected at the supervised drug consumption facilities, the needle exchange service and two low-threshold health services for problem drug users in Oslo, Norway. The material was collected every third month from June 2019 to June 2020 and analysed for 64 substances using highly specific analytical methods (ultra-high performance liquid chromatography tandem mass spectrometry). Additionally, a street-recruited sample of PWID was interviewed from 2017 to 2019 regarding their drug injection habits (n=572).

RESULTS

Heroin (65.5%) or amphetamines (59.8%), often in combination (30.5%), were commonly detected in drug residues. Other opioids, stimulants or benzodiazepines were rarely detected (6.1%). Fentanyl was detected in only one syringe. Heroin was the most reported drug (77.6% during the past four weeks, 48.3% daily/almost daily), followed by amphetamines (57.5% during the past four weeks, 23.1% daily or almost daily). Injection of methadone, buprenorphine and dissolved tablets was self-reported more frequently than determined in drug residue findings.

CONCLUSIONS

Analysis of the injection equipment proved useful as a non-invasive, rapid and accurate means to obtain detailed information on injected drugs in Oslo and supplement traditional PWID survey information.

Trace residue identification, characterization, and longitudinal monitoring of the novel synthetic opioid β-U10, from discarded drug paraphernalia

Empirical data regarding dynamic alterations in illicit drug supply markets in response to the COVID-19 pandemic, including the potential for introduction of novel drug substances and/or increased poly-drug combination use at the "street" level, that is, directly proximal to the point of consumption, are currently lacking. Here, a high-throughput strategy employing ambient ionization-mass spectrometry is described for the trace residue identification, characterization, and longitudinal monitoring of illicit drug substances found within >6,600 discarded drug paraphernalia (DDP) samples collected during a pilot study of an early warning system for illicit drug use in Melbourne, Australia from August 2020 to February 2021, while significant COVID-19 lockdown conditions were imposed. The utility of this approach is demonstrated for the de novo identification and structural characterization of β-U10, a previously unreported naphthamide analog within the "U-series" of synthetic opioid drugs, including differentiation from its α-U10 isomer without need for sample preparation or chromatographic separation prior to analysis. Notably, β-U10 was observed with 23 other drug substances, most commonly in temporally distinct clusters with heroin, etizolam, and diphenhydramine, and in a total of 182 different poly-drug combinations. Longitudinal monitoring of the number and weekly "average signal intensity" (ASI) values of identified substances, developed here as a semi-quantitative proxy indicator of changes in availability, relative purity and compositions of street level drug samples, revealed that increases in the number of identifications and ASI for β-U10 and etizolam coincided with a 50% decrease in the number of positive detections and an order of magnitude decrease in the ASI for heroin.

Substances detected in used syringes of injecting drug users across 7 cities in Europe in 2017 and 2018: The European Syringe Collection and Analysis Project Enterprise (ESCAPE)

BACKGROUND AND AIMS

Injecting drug use is a matter of public health concern, associated with risks of overdoses, addiction and increased risk of bloodborne viral transmissions. Self-reported data on substances injected can be inaccurate or subject to bias or drug users might be oblivious to their injected substances or adulterations. Gathering of robust analytical information on the actual composition of substances injected might provide better information about the drugs that are being used. Therefore, this study aimed to analyse the residual content of discarded syringes collected across 7 European cities, collectively called the European Syringe Collection and Analysis Project Enterprise (ESCAPE).

METHODS

Used syringes were collected at street automatic injection kit dispensers or at harm-reduction services in Amsterdam, Budapest, Cologne, Glasgow, Helsinki, Lausanne and Paris. Two sampling periods were executed thus far, in 2017 and 2018. Qualitative chemical analysis of the content of used syringes was performed combining gas chromatographic (GC) and ultra(high)performance liquid chromatographic ((U)HPLC) analytical techniques with detection by mass spectrometry (MS).

RESULTS

Substances detected most frequently across both campaigns were cocaine, heroin, buprenorphine, amphetamines and synthetic cathinones. In Amsterdam, Cologne, Lausanne and Glasgow heroin and cocaine were the psychoactive substances most often detected, often in conjunction with each other. Helsinki showed a high presence of buprenorphine and amphetamines. In Budapest and Paris, synthetic cathinones were frequently detected. Less synthetic cathinones and cocaine was detected in 2018, whereas buprenorphine was detected almost twice as much. Inner-city variations were found, probably reflecting the types of people who inject drugs (PWID) in different areas of the city.

CONCLUSION

Overall, laboratory-confirmed local data on injected substances showed resemblance to national surveys done among PWID. However, the ESCAPE data also showed some interesting differences, showing it can be used for local interventions and complementing existing monitoring data.

HaRePo (harm reduction by post): an innovative and effective harm reduction programme for people who use drugs using email, telephone, and post service

BACKGROUND

Despite multiple harm reduction (HR) programmes worldwide, there are still an important number of people who use drugs (PWUD) who do not access those services. Their difficulties to obtain HR tools are due to their inability to reach such services (remoteness and/or limited customer service hours), costs, quantitative restrictions, fear of judgement, lack of confidentiality in pharmacy, and unfamiliarity with HR programmes. We tested an innovative approach using the power of remote online communication and the national postal distribution network to improve HR tool access and counselling.

METHODS

Based on these observations, SAFE association created HaRePo in 2011, a free and confidential programme designed for people who have difficulties accessing HR tools and counselling. PWUD can access the programme by phone and/or email. An HR professional delivers HR counselling and HR tools and connects PWUD to other HR services, medical, and social workers. HR tools are prepared and sent according to the person's needs through the French postal service to consumers across Metropolitan France and overseas territories.

RESULTS

Since 2011, 1920 PWUD have benefited from HaRePo: 10,450 parcels were sent accounting for more than 1.7 million syringes and 6 million HR-related items. HaRePo receives positive feedback from PWUD who have improved their practices through remote but trusted communication. The percentage of people that, after joining the programme, never reuse and/or share HR tools have significantly increased. On average, 71.5% of beneficiaries never reuse syringes and 81% do not reuse needles. And they are 98.5% consumers who never share syringes and 99% needles any longer. Between 44 and 80% HaRePo beneficiaries have reported that their drug-related practices (injection, inhalation, and snorting) are now safer. Finally, between 39 and 53% HaRePo consumers declared that their overall physical state has improved (e.g. venous condition, the appearance of point of injection, swelling of arms, legs, and hands).

CONCLUSION

HaRePo is an innovative HR programme efficient for hard-to-reach PWUD. It shows evidence of a positive feedback loop for PWUD in improving their practices. Finally, HaRePo represents a clear benefit for health authorities in France, who decided to expand the programme in 2016.

Analytical findings in used syringes from a syringe exchange program

BACKGROUND

Since it's first implementatation in 1984, Syringe Exchange Programs (SEP) are a critical component of harm reduction interventions among people who inject drugs.. The aim of this work was to use a scientific analytical approach to obtain drug use information through the analysis of the content of used syringes.

METHODS

357 syringes were collected in New York City and submitted to qualitative analysis. Screening analysis was performed by gas chromatography mass spectrometry (GC-MS) and confirmatory analysis by liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF).

RESULTS

Of the 357 syringes analyzed, 275 (77.0%) were positive for one or more substances. The most common drug of abuse identified was heroin/related substances (72.0%), followed by cocaine/related substance (34.9%), fentanyl/related substance (13.5%), methamphetamine/related substance (7.6%) and furanylfentanyl (3.6%). Quinine/quinidine (18.5%) was the most common cutting agent detected, followed by levamisole (12.0%), caffeine (11.6%), lidocaine (11.6%), and phenacetin (6.9%).

CONCLUSION

Analysis of samples collected from a drug street scenario allows the identification of new substances being injected and provides information to harm reduction programs to identify strategies to reduce drug abuse.

Fentanyl is used in Mexico's northern border: current challenges for drug health policies

BACKGROUND AND AIMS

Results from a recent study among 750 heroin users in three Mexico's northern border cities revealed an increase in white powder availability (also known as China white) and preference for this product among heroin users, as well as a general perception of increased overdose cases among this population. Here, we questioned whether those findings reflect an increased presence of heroin laced with fentanyl, which is associated with greater risks of overdose but that, until now, has not been described in Mexico.

DESIGN

We tested fentanyl using highly sensitive test strips in syringe plungers, metal cookers and drug wrappings associated with heroin use.

SETTING

Three injection sites in Tijuana, Baja California, México.

PARTICIPANTS

Eighty-nine heroin users who interchanged paraphernalia for new syringes.

MEASUREMENTS

We tested 59 residues of 'pure' white powder. The rest were white powder with black tar (n = 5) or white powder with crystal meth (n = 9), black tar with crystal meth (n = 1), black tar only (n = 13) and crystal meth only (n = 2).

FINDINGS

Users believed that they consumed either white powder heroin, white powder heroin with crystal meth, white powder with black tar heroin or black tar heroin only. Analyses revealed that 93% (n = 55) of the 'pure' white powder samples had fentanyl. All (n = 9) the white powder samples mixed with crystal meth and 40% (n = 2) of the white powder with black tar were also laced with fentanyl.

CONCLUSIONS

In a sample of 89 heroin users in Mexico, most white powder heroin users were unknowingly exposed to fentanyl, with fentanyl detected in 93% of white powder samples.

Hair testing for 3-fluorofentanyl, furanylfentanyl, methoxyacetylfentanyl, carfentanil, acetylfentanyl and fentanyl by LC–MS/MS after unintentional overdose

Purpose

To demonstrate the usefulness of hair testing to determine exposure pattern to fentanyls.

Methods

A 43-year-old male was found unconscious with respiratory depression 15 min after snorting 3 mg of a powder labeled as butyrylfentanyl. He was discharged from hospital within 2 days without blood or urine testing. Two locks of hair were sampled 1 month (M1 A: 0–2 cm (overdose time frame); B: 2–4 cm; C: 4–6 cm) and 1 year (Y1: A: 0–2 cm; B: 2–4 cm) later to monitor his exposure to drugs of abuse by liquid chromatography–tandem mass spectrometry after liquid-liquid extraction.

Results

Hair analysis at M1 showed a repetitive exposure to 3-fluorofentanyl (A/B/C: 150/80/60 pg/mg) with higher concentration in segment A reflecting the overdose period. The non-detection of butyrylfentanyl was consistent with the analysis of the recovered powder identified as 3-fluorofentanyl. Furanylfentanyl (40/20/15 pg/mg) and fentanyl (37/25/3 pg/mg) were also detected in hair. The second hair analysis at Y1 showed the use of three new fentanyls, with probably repetitive exposures to methoxyacetylfentanyl (A/B: 500/600 pg/mg), and single or few exposures to carfentanil (2.5/3 pg/mg) and acetyl fentanyl (1/1 pg/mg). A decreasing exposure to 3-fluorofentanyl (25/80 pg/mg), and increasing consumption of furanylfentanyl (310/500 pg/mg) and fentanyl (620/760 pg/mg) were also observed despite methadone treatment initiation. The patient claimed not consuming three out of the six detected fentanyls.

Conclusions

We report single or repetitive exposure to several fentanyls using hair testing. To our knowledge, this is the first demonstration of 3-fluorofentanyl and methoxyacetylfentanyl in hair samples collected from an authentic abuser.

New psychoactive substances: challenges for drug surveillance, control, and public health responses

The rapid emergence since the mid-2000s of a large and diverse range of substances originally designed as legal alternatives to more established illicit drugs (pragmatically clustered and termed new psychoactive substances; [NPS]) has challenged traditional approaches to drug monitoring, surveillance, control, and public health responses. In this section of the Series, we describe the emergence of NPS and consider opportunities for strengthening the detection, identification, and responses to future substances of concern. First, we explore the definitional complexity of the term NPS. Second, we describe the origins and drivers surrounding NPS, including motivations for use. Third, we summarise evidence on NPS availability, use, and associated harms. Finally, we use NPS as a case example to explore challenges and opportunities for future drug monitoring, surveillance, control, and public health responses. We posit that the current means of responding to emerging substances might no longer be fit for purpose in a world in which different substances can be rapidly introduced, and where people who use drugs can change preferences on the basis of market availability.

Prevalence of New Psychoactive Substances (NPS) and conventional drugs of abuse (DOA) in high risk populations from Paris (France) and its suburbs: A cross sectional study by hair testing (2012-2017)

BACKGROUND

The aim of the present study is to describe the prevalence of NPS and conventional DOA in Paris and its suburbs over a six-year period using hair testing approach.

METHOD

Hair was sampled in patients admitted to different departments of Paris hospitals between 2012 and 2017. Two high-risk populations were mainly considered: 1) drug-dependent and 2) acutely intoxicated patients. Segmental hair analysis was performed by validated LC-MS/MS method to screen for DOA and 83 NPS.

RESULTS

480 patients (280 M/200 F, 15-70 years) were included. 141 patients tested positive for NPS (99 M/42 F; median age: 33). NPS prevalence was 29%, that of amphetamines, cocaine and opioids were 32%, 38.5% and 52%, respectively. 27 NPS were identified, 4-MEC and mephedrone (number of cases n = 24 each) were the most detected cathinones. JWH-122 (n = 1) was the only detected synthetic cannabinoid while ketamine (n = 104) was present in numerous NPS users (67%). 3-fluorofentanyl (n = 1), furanylfentanyl (n = 1), N-ethylpentylone (n = 2), pentedrone (n = 2), mexedrone (n = 1), methcathinone (n = 3), 6-APDB (n = 2), TFMPP (n = 2), 2-CE (n = 1), 3,4-MD-αPHP (n = 1) and dextromethorphan (n = 27) were identified for the first time in hair. Users were found to have more than one NPS in 53% of cases, mostly in combination with conventional DOA. The number of detected NPS rose from 5 in 2012 to 42 in 2017. A broad range of hair concentrations (0.001-318 ng/mg) was found, but the low median concentrations seem to show an occasional exposure more than chronic use.

CONCLUSION

NPS screening should be assessed in routine clinical practice, especially in high-risk populations.

Age of Initiation and Patterns of Use among People Who Inject Drugs Welcomed in Harm Reduction Facilities in France from 2006 to 2015

This exploratory analysis of time-series cross-sectional data provides insights on trends in age at first injection among people who inject drugs in France, and on associations with recent risky injecting behaviors. Data were collected from a national survey conducted in harm reduction facilities in five phases between 2006 and 2015. Standardized questionnaires collected information on demographics, substance use, and route of administration, as well as lifetime and past-month injection. Descriptive and multilevel models were applied to account for the hierarchical structure of the data. Prevalence of lifetime and past-month injection remained stable over time, while the prevalence of daily injection increased significantly. Mean age at first injection only appeared to increase for data collected after 2010. Gender differences in mean age at first injection decreased over time, suggesting the development of converging patterns of initiation independent of sex. After controlling for covariates, early initiation of injection was unrelated to daily injection or material sharing, and associated with the number of recently injected substances. Early initiation is likely a predictor of injected polysubstance use. Findings are relevant to the planning, implementation, and evaluation of prevention programs.

Estimating the Risk of Exposure to Fentanyl in New York City: Testing Drug Residue in Used Syringes

OBJECTIVES

To estimate the risk of exposure to fentanyl among syringe exchange program (SEP) participants in New York City.

METHODS

We recruited a convenience sample from 11 SEPs in New York City between March and June 2017. Consenting participants (n = 434) received a labeled syringe for their next injection. We tested collected syringes with gas chromatography-mass spectrometry and liquid chromatography-quadrupole-time-of-flight mass spectrometry. Fentanyl or fentanyl analogs detected in quantities greater than 10% of the residue mass were reported.

RESULTS

The final analysis included 271 syringes; 46 (17.0%) contained fentanyl or a fentanyl analog. Fentanyl was the most frequently identified fentanyl compound, identified in 36 (13.3%) syringes. Furanylfentanyl was detected in 10 (3.7%) syringes, and 4-fluoroisobutyryl fentanyl was detected in 5 (1.8%) syringes.

CONCLUSIONS

The risk of exposure to fentanyl in syringes used by SEP participants was significantly lower significantly lower than the amount of fentanyls identified among overdose decedents in New York City. Further research is needed to understand how people who use drugs have adapted to fentanyl in the drug market. Understanding the risk of exposure to fentanyls is critical to development of targeted public health messaging.

Analysis of residual content of used syringes collected from low threshold facilities in Lausanne, Switzerland

BACKGROUND

For the first time in Switzerland, an analysis of residual contents from used syringes collected from low threshold facilities was performed. This preliminary study is part of a wider project aiming to understand patterns of injecting drug use over time.

METHODS

Among the 100,000 syringes exchanged annually by the ABS foundation (Accueil Bas Seuil), 113 were collected following a purposive sampling method and analysed by gas chromatography coupled with mass spectrometry (GC-MS).

RESULTS

Four syringes (4% of the sample population) contained no substances take into consideration the limit of the method. Cocaine was the most commonly observed compound and was detected in 77 syringes (68%), whilst users reported syringes with cocaine among those analysed in this study. Heroin was detected in 49 syringes (43%) and reported by 53 users returning syringes; midazolam was detected in 31 syringes (27%) and reported as the medicine Dormicum(®) in 22 occurrences. No new or unusual illicit drug was detected in the sample.

CONCLUSION

The results show the presence of cocaine in more than half of the sample, an absence of new or unusual illicit drugs, as well as very few traces of methadone, which suggests that this substitution drug is rarely injected. This preliminary study also demonstrates the potential of this developed methodology for monitoring purposes. An ongoing and more systematic approach could allow to detect modifications in drug use patterns among the target population as well as the appearance of new and hazardous substances. Such systematic and timely results could allow an adaptation of harm reduction interventions.

Data triangulation in the context of opioids monitoring via wastewater analyses

BACKGROUND

The need to contextualise wastewater-based figures about illicit drug consumption by comparing them with other indicators has been stressed by numerous studies. The objective of the present study was to further investigate the possibility of combining wastewater data to conventional statistics to assess the reliability of the former method and obtain a more balanced picture of illicit drug consumption in the investigated area.

METHODS

Wastewater samples were collected between October 2013 and July 2014 in the metropolitan area of Lausanne (226,000 inhabitants), Switzerland. Methadone, its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), the exclusive metabolite of heroin, 6-monoacetylmorphine (6-MAM), and morphine loads were used to estimate the amounts of methadone and heroin consumed.

RESULTS

Methadone consumption estimated from EDDP was in agreement with the expectations. Heroin estimates based on 6-MAM loads were inconsistent. Estimates obtained from morphine loads, combined to prescription/sales data, were in agreement with figures derived from syringe distribution data and general population surveys.

CONCLUSIONS

The results obtained for methadone allowed assessing the reliability of the selected sampling strategy, supporting its ability to capture the consumption of a small cohort (i.e., 743 patients). Using morphine as marker, in combination with prescription/sales data, estimates in accordance with other indicators about heroin use were obtained. Combining different sources of data allowed strengthening the results and suggested that the different indicators (i.e., administration route, average dosage and number of consumers) contribute to depict a realistic representation of the phenomenon in the investigated area. Heroin consumption was estimated to approximately 13 gd ay(-1) (118 g day(-1) at street level).