Deficit of circulating stem--progenitor cells in opiate addiction: a pilot study

What are the characteristics of vitamin D metabolism in opioid dependence? An exploratory longitudinal study in Australian primary care

OBJECTIVE

Compare vitamin D levels in opioid dependence and control population and adjust for relevant confounding effects. Nuclear hormone receptors (including the vitamin D receptor) have been shown to be key transducers and regulators of intracellular metabolism and comprise an important site of pathophysiological immune and metabolic dysregulation potentially contributing towards pro-ageing changes observed in opioid-dependent patients (ODPs).

DESIGN

Longitudinal prospective comparing ODPs with general medical controls (GMCs).

SETTING

Primary care.

PARTICIPANTS

Prospective review comparing 1168 ODP (72.5% men) and 415 GMC (51.6% men, p<0.0001). Mean ages were 33.92±0.31 (mean±SEM) and 41.22±1.32 years, respectively (p<0.0001). Opioid use in the ODP has been previously reported and shown to be typical.

INTERVENTIONS

Nil. Observational study only.

PRIMARY AND SECONDARY OUTCOMES

Serum vitamin D levels and relevant biochemical parameters.

RESULTS

Vitamin D levels were higher in the ODP (70.35±1.16 and 57.06±1.81 nmol/L, p<0.0001). The difference in ages between the two groups was handled in an age-matched case-control subanalysis and also by multiple regression. Sexes were analysed separately. The age:status (or age:time:status) was significant in case-control, cross-sectional and longitudinal analyses in both sexes (p<0.05). Modelled vitamin D was 62.71 vs 57.81 nmol/L in the two groups. Time-dependent mixed-effects models quadratic in age outperformed linear-only models (p=0.0377). ODP vitamin D was shown to vary with age and to correlate with alanine aminotransferase establishing it as a biomarker of age in this group. Hepatitis C seronegativity was significant in regression models (from p=0.0015).

CONCLUSION

Vitamin D was higher in ODP in both sexes in bivariate, cross-sectional, case-control and longitudinal analyses and was robust to the inclusion of metabolic and immune biomarkers. That Hepatitis C seronegativity was significant suggests opioid dependence has an effect beyond simply that of its associated hepatitides. This finding may relate to the accelerated ageing process previously described in opioid dependence.

Sex-specific linkage scans in opioid dependence

Sex influences risk for opioid dependence (OD). We hypothesized that sex might interact with genetic loci that influence the risk for OD. Therefore we performed an analysis to identify sex-specific genomic susceptibility regions for OD using linkage. Over 6,000 single nucleotide polymorphism (SNP) markers were genotyped for 1,758 African- and European-American (AA and EA) individuals from 739 families, ascertained via affected sib-pairs with OD and/or cocaine dependence. Autosomewide non-parametric linkage scans, stratified by sex and population, were performed. We identified one significant linkage region, segregating with OD in EA men, at 71.1 cM on chromosome 4 (LOD = 3.29; point-wise P = 0.00005; empirical autosome-wide P = 0.042), which significantly differed from the linkage signal at the same location in EA women (empirical P = 0.002). Three suggestive linkage signals were identified at 181.3 cM on chromosome 7 (LOD = 2.18), 104 cM on chromosome 11 (LOD = 1.85), and 60.9 cM on chromosome 16 (LOD = 1.93) in EA women. In AA men, four suggestive linkage signals were detected at 201.1 cM on chromosome 3 (LOD = 2.32), 152.9 cM on chromosome 6 (LOD = 1.86), 16.8 cM on chromosome 7 (LOD = 1.95), and 36.1 cM on chromosome 17 (LOD = 1.99). The significant region, mapping to 4q12-4q13.1, harbors several OD candidate genes with interconnected functionality, including VEGFR, CLOCK, PDCL2, NMU, NRSF, and IGFBP7. In conclusion, these results provide an evidence for the existence of sex-specific and population-specific differences in OD. Furthermore, these results provide positional information that will facilitate the use of targeted next-generation sequencing to search for genes that contribute to sex-specific differences in OD. © 2016 Wiley Periodicals, Inc.

Impact of lifetime opioid exposure on arterial stiffness and vascular age: cross-sectional and longitudinal studies in men and women

OBJECTIVE

To characterise and compare the potentiation of arterial stiffness and vascular ageing by opioids in men and women.

DESIGN

Cross-sectional and longitudinal studies of 576 clinical controls and 687 opioid-dependent patients (ODP) on 710 and 1305 occasions, respectively, over a total of 2382 days (6.52 years), 2006-2011. Methodology Radial pulse wave analysis with Atcor SphygmoCor system (Sydney).

SETTING

Primary care.

CONTROLS

General practice patients with non-cardiovascular disorders, and university student controls. ODP: Patients undergoing clinical management of their opioid dependence. CONTROLS had lower chronological ages (CAs) than ODP (30.0±0.5 vs 34.5±0.3, mean±SEM, p<0.0001). 69.6% and 67.7% participants were men, and 16% and 92.3% were smokers (p<0.0001) for controls and ODP, respectively. 86.3%, 10.3% and 3.4% of ODP were treated with buprenorphine (6.98±0.21 mg), methadone (63.04±4.01 mg) or implant naltrexone, respectively. Body mass index (BMI) was depressed in ODP.

INTERVENTIONS

Nil.

PRIMARY OUTCOME MEASURES

Vascular Reference Age (RA) and the ratio of vascular age to chronological age (RA/CA).

SECONDARY OUTCOME MEASURES

Arterial stiffness including Augmentation Index.

RESULTS

After BMI adjustment, RA in ODP was higher as a function of CA and of time (both p<0.05). Modelled mean RA in control and ODP was 35.6 and 36.3 years (+1.97%) in men, and 34.5 and 39.2 years (+13.43%) in women, respectively. Changes in RA and major arterial stiffness indices were worse in women both as a factor (p = 0.0036) and in interaction with CA (p = 0.0040). Quadratic, cubic and quartic functions of opioid exposure duration outperformed linear models with RA/CA over CA and over time. The opioid dose-response relationship persisted longitudinally after multiple adjustments from p=0.0013 in men and p=0.0073 in women.

CONCLUSIONS

Data show that lifetime opioid exposure, an interactive cardiovascular risk factor, particularly in women, is related to linear, quadratic, cubic and quartic functions of treatment duration and is consistent with other literature of accelerated ageing in patients with OD.

Prenatal buprenorphine exposure decreases neurogenesis in rats

Perinatal opioid exposure has a negative effect on neurogenesis and produces neurological consequences. However, its mechanisms of action are incompletely understood. Buprenorphine, a mixed opioid agonist/antagonist, is an alternative medication for managing pregnant opioid addicts. This study provides evidence of decreased neurogenesis and depression-like consequences following prenatal exposure to buprenorphine and sheds light on mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant rats starting from gestation day 7 and lasting for 14 days and a cultured neurosphere model. Results of forced swimming test and tail suspension test showed that pups at postnatal day 21 had worse parameters of depression-like neurobehaviors, independent of gender. Neurobehavioral changes were accompanied by reduction of neuronal composition, biochemical parameters of neural stem/progenitor cells, brain-derived neurotrophic factor (BDNF) expression, tropomyosin-related kinase receptor type B phosphorylation, protein kinase A (PKA) activity, and cAMP response element-binding protein phosphorylation. Results of parallel cell studies further demonstrated a negative impact of buprenorphine on cultured neurospheres, including proliferation, differentiation, BDNF expression and signaling, and PKA activity. Taken together, our results suggest that prenatal exposure to buprenorphine might result in depression-like phenotypes associated with impaired BDNF action and decreased neurogenesis in the developing brain of weanlings.

Opium use and risk of mortality from digestive diseases: a prospective cohort study

OBJECTIVES

Opium use, particularly in low doses, is a common practice among adults in northeastern Iran. We aimed to investigate the association between opium use and subsequent mortality from disorders of the digestive tract.

METHODS

We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50,045 adults were enrolled during a 4-year period (2004-2008) and followed annually until December 2012, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest.

RESULTS

In all, 8,487 (17%) participants reported opium use, with a mean duration of 12.7 years. During the follow-up period 474 deaths from digestive diseases were reported (387 due to gastrointestinal cancers and 87 due to nonmalignant etiologies). Opium use was associated with an increased risk of death from any digestive disease (adjusted hazard ratio (HR)=1.55, 95% confidence interval (CI)=1.24-1.93). The association was dose dependent, with a HR of 2.21 (1.57-3.31) for the highest quintile of cumulative opium use vs. no use (Ptrend=0.037). The HRs (95% CI) for the associations between opium use and malignant and nonmalignant causes of digestive mortality were 1.38 (1.07-1.76) and 2.60 (1.57-4.31), respectively. Increased risks were seen both for smoking opium and for ingestion of opium.

CONCLUSIONS

Long-term opium use, even in low doses, is associated with increased risk of death from both malignant and nonmalignant digestive diseases.

Elevation of central arterial stiffness and vascular ageing in opiate withdrawal: cross-sectional and longitudinal studies

The central cardiovascular impacts of clinical opiate withdrawal have not been explored in detail. Pulse Wave Analysis (SphygmoCor) was conducted in healthy controls and opiate-dependent populations. A total of 1,294 patients (69.2 % male) were studied in quintuplicate on 2,089 occasions. Four groups were studied: control (N = 576), buprenorphine stabilized (N = 592), withdrawal (N = 112) and severe withdrawal (N = 14). Control patients were younger than the other groups (29.96 ± 0.45 years v. 32.53 ± 0.74-39.28 ± 3.86) but had similar sex ratios. Multiple regression was used to correct for the effects of age, and significant exacerbations were found in withdrawal in the vascular age (RA), augmentation index, subendocardial perfusion ratio (SEVR <100; R.R. 2.07 95 % C.I. 1.17-3.68, P = 0.02) and central systolic pressure both as factors themselves and in interactions with age (all P < 0.01). The elevation of modelled RA at 60 years was from 69.66 in controls to 97.54 in withdrawal (40.02 %). The effects on RA were found in both sexes and confirmed on longitudinal analysis. The elevation of RA in withdrawal was most marked after 40 years of age (P = 0.027). These results show increased vascular stiffness and cardiovascular age but reduced subendocardial perfusion in opiate withdrawal. Given the daily recurrent nature of withdrawal, these effects are likely cumulative.

Lifetime opiate exposure as an independent and interactive cardiovascular risk factor in males: a cross-sectional clinical study

Introduction

While several studies have identified an increased incidence of cardiovascular disorders in opiate dependence, neither opiates as a cardiovascular risk factor nor their effect on central arterial function has been considered.

Methods

Pulse wave analysis (SphygmoCor, AtCorMedical Pty Limited, Sydney, NSW, Australia) was undertaken on a cohort of controls and opiate dependent patients and the results compared to their lifetime opiate exposure.

Results

Controls (N = 401) were compared with 465 opiate dependent men. The mean (log) ages were different and were found to be 28.80 ± 0.49 years versus 35.02 ± 0.39 years (P < 0.0001), respectively. Of the opiate dependent group, 87.7% were treated with buprenorphine, 8.8% with methadone, and 3.4% with naltrexone. Multiple regression analysis was used to adjust for chronologic age (CA). At CA of 60 years, the modeled age in the controls was 66.40 years, and that in the addicted group was 73.11 years, an advancement of 6.71 years, or 10.10%. Exacerbations of age dependent changes in central arterial stiffness, central pressures, pulse rate, ejection duration, diastolic duration, and subendocardial perfusion ratio by opiate dependence were all noted (P < 0.05). Current heroin dose, heroin duration, and the dose duration interaction were all significantly related to the vascular (or “reference”) age (RA)/CA ratio (all P < 0.006). After multivariate adjustment, the opiate dose duration was independently predictive of RA (P < 0.02). Opiate dose and/or duration were included in a further 25 terms.

Conclusion

These data show that opiate use is not benign for the male cardiovascular system, but has a dose response relationship to central arterial stiffness and thus cardiovascular aging, acting independently and interactively with established cardiovascular risk factors. These findings imply accelerated organismal aging.

Reduction in arterial stiffness and vascular age by naltrexone-induced interruption of opiate agonism: a cohort study

OBJECTIVE

To prospectively assess if opiate antagonist treatment or the opiate-free status could reverse opiate-related vasculopathy.

DESIGN

Longitudinal Open Observational, Serial 'N of One', over 6.5 years under various treatment conditions: opiate dependence, naltrexone and opiate-free.

SETTING

Primary care, Australia.

PARTICIPANTS

20 opiate-dependent patients (16 males: 16 cases of buprenorphine 4.11±1.17 mg, two of methadone 57.5±12.5 mg and two of heroin 0.75±0.25 g).

INTERVENTION

Studies of central arterial stiffness and vascular reference age (RA) were performed longitudinally by SphygmoCor Pulse Wave Analysis (AtCor, Sydney).

PRIMARY OUTCOMES

Primary outcome was vascular age and arterial stiffness accrual under different treatment conditions.

RESULTS

The mean chronological age (CA) was 33.62±2.03 years. The opiate-free condition was associated with a lower apparent vascular age both in itself (males: p=0.0402 and females: p=0.0360) and in interaction with time (males: p=0.0001 and females: p=0.0004), and confirmed with other measures of arterial stiffness. The mean modelled RA was 38.82, 37.73 and 35.05 years in the opiate, naltrexone and opiate-free conditions, respectively. The opiate-free condition was superior to opiate agonism after full multivariate adjustment (p=0.0131), with modelled RA/CA of 1.0173, 0.9563 and 0.8985 (reductions of 6.1% and 11.9%, respectively).

CONCLUSIONS

Data demonstrate that opiate-free status improves vascular age and arterial stiffness in previous chronic opiate users. The role of opiate antagonist treatment in achieving these outcomes requires future clarification and offers hope of novel therapeutic remediation.

High-sensitivity CRP in opiate addiction: relative and age-dependent elevations

High-sensitivity C-reactive protein (hs-CRP) has been shown to be linked with immune stimulation, but is not well studied over the lifetime in opiate addiction. hs-CRP was measured by standard laboratory methods in substance use disorder (SUD) patients and non-SUD (NSUD) aged 18-48 years. Data were log transformed to improve normality. 1231 SUD were compared with 326 NSUD patients of comparable ages. hs-CRP was 7.46 ± 14.24 versus 4.75 ± 13.40 mg/l (mean ± SD) significantly higher in the SUD group (P < 0.0001), a difference which persisted after exclusion of acutely elevated hs-CRP values (P < 0.0001). In multiple regression with age, addictive status was significant both by itself (P < 0.0001) and in interaction with age (P < 0.0001). At age 40 years, the SUD group had a mean hs-CRP of 3.68 which the NSUD group did not achieve till a modelled age of 157.09 years. In an interactive multivariate regression, interactions between age, addictive status, ALT and AST were significant. These data show that hs-CRP is elevated in opiate dependence both per se, and when controlled for age. Furthermore, they suggest that hs-CRP and immune stimulation seen in opiate addiction may underlie the acceleration of age-related multi-system chronic and coronary atherosclerotic disease well described in opiate dependence.

Epidemiologic and Molecular Pathophysiology of Chronic Opioid Dependence and the Place of Naltrexone Extended-Release Formulations in its Clinical Management

Naltrexone implants and depot injections (NI) are a novel form of treatment for opiate dependence (OD). Major questions relate to their absolute and relative efficacy and safety. Opportunely, six recent clinical trial data from several continents have uniformly provided dramatic evidence of the potent, dose-related and highly significant efficacy of NI, with minimal or manageable accompanying toxicity and safety concerns. The opiate-free lifestyle is attained significantly more often with NI adjusted O.R. = 6.00 (95% C.I. 3.86–9.50), P < 10⁻¹⁰. Other drug use and drug craving are also rapidly reduced. The optimum manner in which to commence NI remains to be established. Of particular relevance is the relative safety of NI compared to the chronic opiate agonists (COA) usually employed, as the long-term toxicity of COA is only just being elucidated. Large population-based studies have found elevated rates of cardiovascular disease, six cancers, liver and respiratory disease, and all-cause mortality in COA. Whilst opiates have been shown to trigger numerous molecular pathways, the most interesting is the demonstration that the opiate morphinan’s nucleus binds to the endotoxin groove of the TLR4-MD2 heterodimer. This has the effect of triggering a low grade endotoxaemic-like state, which over time may account for these protean clinical findings, an effect which is reversed by opiate antagonists. This emerging evidence suggests an exciting new treatment paradigm for OD and a corresponding increase in the role of NI in treatment.

Pharmacological enhancement of naltrexone treatment for opioid dependence: a review

PURPOSE: Opioid dependence (OD) is a serious and growing clinical condition with increasing social costs that requires expanding treatment beyond opioid agonist substitution. The opioid antagonist naltrexone has displayed a remarkable association of theoretical effectiveness and poor clinical utility in treating OD due to noncompliant behavior and low acceptability among patients, only partly modified by psychosocial interventions. We reviewed pharmacological studies, including naltrexone depot formulations and combination treatments. METHOD: We searched PubMed for clinical studies on the use of naltrexone implants and slow-release injections in OD, and investigations using adjunct medications to improve naltrexone maintenance therapy of OD. We discussed the results in view of their application to the clinical practice. RESULTS: Significant reduction in opioid use and improved retention in treatment have been found in several studies using depot naltrexone formulations, some of which are controlled clinical trials. Pilot investigations have gathered initial positive results on the use of naltrexone in combination with serotonin reuptake inhibitors, α-2 adrenergic, opioid, and γ-aminobutyric acid agonist medications. CONCLUSION: Current evidence suggests that more research on effectiveness and safety is needed in support of depot naltrexone treatment for OD. Further research comparing slow-release with oral naltrexone and opioid agonist medications will help characterize the role of opioid antagonist-mediated treatment of OD. Preliminary investigations on naltrexone combination treatments suggest the opportunity to continue study of new mixed receptor activities for the treatment of OD and other drug addictions.

Favorable mortality profile of naltrexone implants for opiate addiction

Several reports express concern at the mortality associated with the use of oral naltrexone for opiate dependency. Registry controlled follow-up of patients treated with naltrexone implant and buprenorphine was performed. In the study, 255 naltrexone implant patients were followed for a mean (+/- standard deviation) of 5.22 +/- 1.87 years and 2,518 buprenorphine patients were followed for a mean (+/- standard deviation) of 3.19 +/- 1.61 years, accruing 1,332.22 and 8,030.02 patient-years of follow-up, respectively. The crude mortality rates were 3.00 and 5.35 per 1,000 patient-years, respectively, and the age standardized mortality rate ratio for naltrexone compared to buprenorphine was 0.676 (95% confidence interval = 0.014 to 1.338). Most sex, treatment group, and age comparisons significantly favored the naltrexone implant group. Mortality rates were shown to be comparable to, and intermediate between, published mortality rates of an age-standardized methadone treated cohort and the Australian population. These data suggest that the mortality rate from naltrexone implant is comparable to that of buprenorphine, methadone, and the Australian population.

Chronic immune stimulation as a contributing cause of chronic disease in opiate addiction including multi-system ageing

Evidence of immune stimulation has been noted in opiate dependent patients for many decades. Documented changes have included lymphadenopathy, round cell infiltration of the hepatic portal triads, diffuse peri-bronchitis, hyperglobulinaemia, lymphocytosis, monocytosis, systemic cytokine stimulation, and cytokine and chemokine activation within the neuraxis. A parallel literature describes an elevated list of chronic degenerative disease as common in such patients including neurodegenerative conditions, atherosclerosis, nephrosclerosis, hepatic fibrosis and cirrhosis, chronic obstructive and fibrotic lung disease, osteoporosis, chronic periodontitis, various cancers, hair greying, and stem cell suppression. All of these disorders are now known to have an important immunological role in their pathogenic pathways. The multisystem nature of these myriad changes strongly suggest that the ageing process itself is stimulated in these patients. The link between the immunostimulation on the one hand and the elevated and temporally advanced nature of the chronic degenerative diseases on the other appears not to have been made in the literature. Moreover as immunostimulation is also believed to be an important, potent and principal contributor to the ageing process it appears that experimental and studies of this putative link are warranted. Verification of such an hypothesis would also carry management implications for dose and duration of chronic pain and addiction treatment, pharmacotherapeutic selection, and novel treatments such as long term naltrexone implant therapy and heroin trials.

Comparative treatment and mortality correlates and adverse event profile of implant naltrexone and sublingual buprenorphine

There is increasing interest in the use of implantable naltrexone as a new treatment for opiate dependence. This center has been one of the leaders in this form of treatment in Australia and has recently completed a registry-controlled review of our mortality data. As part of the study of the safety profile of this therapy, we were interested to review both the treatment correlates of previously presented mortality data and of adverse events. A total of 255 naltrexone implant therapy (NIT) and 2,518 buprenorphine (BUP) patients were followed for 1,322.22 and 8,030.02 patient-years, respectively. NIT patients had significantly longer days in treatment per episode (mean +/- standard deviation, 238.32 +/- 110.11 vs. 46.96 +/- 109.79), total treatment duration (371.21 +/- 284.64 vs. 162.50 +/- 245.76), and mean treatment times but fewer treatment episodes than BUP (all p < .0001). Serious local tissue reaction or infection each occurred in 1% of 200 NIT episodes. These data show that NIT economizes treatment resources without compromising safety concerns.

Chronic viral hepatitis is a significant contributor to the immunosenescent phenotype of parenteral drug addiction

Intravenous drug addiction is known to be associated with an inordinate morbidity and mortality. As our previous report had identified an immune phenotype consistent with accelerated ageing, we wished to investigate how much of this change may have been related to chronic viral hepatitis. A total of 12 409 clinical pathology results from the period 1995-2007 were reviewed. To control for the differences in age, only patients less than 48 years of age were considered. A total of 636 substance use disorder (SUD) and 6103 non-SUD (N-SUD) patients were studied. They had comparable ages (mean +/- SD 31.32 +/- 6.90 versus 31.57 +/- 9.23, P-value not significant), but the SUD group had more males (74.37% versus 53.20%, P < 0.001). For most of the changes examined splitting the two SUD groups into hepatitis C positive (HCV+) and hepatitis C negative (HCV-) demonstrated that the majority of the described changes were most marked in the HCV+ group. The globulins were higher in the HCV+ group and the albumin was lower and fell more markedly with age than in N-SUD or HCV- (all P < 0.001). The globulin/albumin ratio was significantly higher in HCV+ than HCV- or N-SUD (both P < 0.0001) and rose more with age. These changes were paralleled by the ESR, elevations in the CRP and lymphocyte count. Transaminases were elevated in SUD and HCV+ groups compared with N-SUD (all P < 0.02). At multivariate analysis ESR, lymphocyte count, dual hepatitis B and C seropositivity, AST and HCVAb were significant predictors of the serum globulin level and accounted for 21% of the variance. These data extend our earlier report and show that much of the immunosenescent phenotype of SUD, encompassing the known immunosuppression and the observed immunostimulation, is statistically related to chronic viral hepatitis. Important theoretical and practical management (vaccination) implications ensue.

An intriguing association between dental and mental pathology in addicted and control subjects: a cross-sectional survey

BACKGROUND

Recent clinical studies suggest that substance use may be associated with an acceleration of the ageing process, possibly related to a deficit of stem cell number or function. As this clinic had access to both medical and drug dependent patients, we tested the hypothesis that there may be an association between previously identified deficits.

METHODS

A cross-sectional survey was performed looking at both dental and mental dysfunction. Both a dental index (DI) and a mental index (MI) were defined as previously described and utilised as summary measures of such pathology.

FINDINGS

From 249 substance use disorder (SUD) and 134 general medical controls (N-SUD), 248 and 91 patients were selected with ages less than 57 years as the primary focus of analysis. The mean (+/- S.D.) ages (32.59 +/- 7.98 vs 35.65 +/- 15.45 years) were similar. The DI was found to correlate with the MI in a significant manner in SUD (R = 0.14, p = 0.03), N-SUD (R = 0.27, p = 0.009) and in the whole group (R = 0.17, p = 0.001). The (univariate) association of MI with DI (p = 0.019) and DI with MI (p = 0.0037) remained highly significant at multivariate regression after adjustment for psychiatric diagnoses and measures of dose-duration exposure to common addictive drugs. The qualitative appearance of the surfaces of best fit for the relationship between age, DI and MI was different in the two groups.

CONCLUSIONS

These results suggest that the robust statistical association between dental and mental pathology may be related to common underlying pathophysiological mechanisms such as a progeroid or stem cell deficiency process in clinical addiction.

Experience of road and other trauma by the opiate dependent patient: a survey report

Background

Trauma plays an important role in the experience of many patients with substance use disorder, but is relatively under-studied particularly in Australia. The present survey examined the lifetime prevalence of various forms of trauma including driving careers in the context of relevant medical conditions.

Methods

A survey was undertaken in a family medicine practice with a special interest in addiction medicine in Brisbane, Australia.

Results

Of 350 patients surveyed, 220 were substance dependent, and 130 were general medical patients. Addicted patients were younger (mean ± S.D. 33.72 ± 8.14 vs. 44.24 ± 16.91 years, P < 0.0001) and had shorter driving histories (15.96 ± 8.50 vs. 25.54 ± 15.03 years, P < 0.0001). They had less driving related medical problems (vision, spectacle use, diabetes) but more fractures, surgical operations, dental trauma and assaults. Addicted patients also had significantly worse driving histories on most parameters measured including percent with driving suspensions (O.R. = 7.70, C.I. 4.38–13.63), duration of suspensions (1.71 ± 3.60 vs. 0.11 ± 0.31 years, P < 0.0001), number of motor vehicle collisions (2.00 ± 3.30 vs. 1.10 ± 1.32, P = 0.01), numbers of cars repaired (1.73 ± 3.59 vs. 1.08 ± 1.60, P = 0.042), rear end collisions (O.R. = 1.90, CI 1.13–3.25), running away after car crashes (O.R. = 26.37, CI 4.31–1077.48), other people hospitalized (O.R. = 2.00, C.I. 0.93–4.37, P = 0.037) and people killed (17 vs. 0 P = 0.0005). Upon multivariate analysis group membership was shown to be a significant determinant of both cars repaired and cars hit when controlled for length of driving history. Hence use of all types of drugs (O.R. = 10.07, C.I. 8.80–14.72) was more common in addicted patients as were general (O.R. = 3.64, C.I. 2.99–4.80) and road (O.R.= 2.73, C.I. 2.36–3.15) trauma.

Conclusion

This study shows that despite shorter driving histories, addicted patients have worse driving careers and general trauma experience than the comparison group which is not explained by associated medical conditions. Trauma is relevant to addiction management at both the patient and policy levels. Substance dependence policies which focus largely on prevention of virus transmission likely have too narrow a public health focus, and tend to engender an unrealistically simplistic and trivialized view of the addiction syndrome. Reduction of drug driving and drug related trauma likely require policies which reduce drug use per se, and are not limited to harm reduction measures alone.

Psychosocial and treatment correlates of opiate free success in a clinical review of a naltrexone implant program

BACKGROUND

There is on-going controversy in relation to the efficacy of naltrexone used for the treatment of heroin addiction, and the important covariates of that success. We were also interested to review our experience with two depot forms of implantable naltrexone.

METHODS

A retrospective review of patients' charts was undertaken, patients were recalled by telephone and by letter, and urine drug screen samples were collected. Opiate free success (OFS) was the parameter of interest. Three groups were defined. The first two were treated in the previous 12 months and comprised "implant" and "tablet" patients. A third group was "historical" comprising those treated orally in the preceding 12 months.

RESULTS

There were 102, 113 and 161 patients in each group respectively. Groups were matched for age, sex, and dose of heroin used, but not financial status or social support. The overall follow-up rate was 82%. The Kaplan Meier 12 month OFS were 82%, 58% and 52% respectively. 12 post-treatment variables were independently associated with treatment retention. In a Cox proportional hazard multivariate model social support, the number of detoxification episodes, post-treatment employment, the use of multiple implant episodes and spiritual belief were significantly related to OFS.

CONCLUSION

Consistent with the voluminous international literature clinically useful retention rates can be achieved with naltrexone, which may be improved by implants and particularly serial implants, repeat detoxification, meticulous clinical follow-up, and social support. As depot formulations of naltrexone become increasingly available such results can guide their clinical deployment, improve treatment outcomes, and enlarge the policy options for an exciting non-addictive pharmacotherapy for opiate addiction.