Effects of flupenthixol and quadazocine on self-administration of speedball combinations of cocaine and heroin by rhesus monkeys.
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The simultaneous i.v. administration of heroin and cocaine, called "speedball," is often reported clinically, and identification of effective pharmacotherapies for polydrug abuse is a continuing challenge. This study compared the effects of treatment using combinations of dopamine and opioid antagonists with each antagonist alone on speedball self-administration by rhesus monkeys. Speedballs (0.01 mg/kg/inj cocaine and 0.0032 mg/kg/inj heroin) and food (1 g banana pellets) were available in four daily sessions on a second-order schedule of reinforcement [FR4 (VR16:S)]. Monkeys were treated for 10 days with saline or ascending 1:10 dose combinations of the dopamine antagonist flupenthixol and the opioid antagonist quadazocine. The combination of flupenthixol (0.018 mg/kg/day) + quadazocine (0.18 mg/kg/day) significantly reduced speedball self-administration in comparison to the saline treatment baseline (p < .05), whereas, the same doses of each antagonist alone had no significant effect on speedball-maintained responding. Treatment with 0.018 mg/kg/day flupenthixol + 0.18 mg/kg/day quadazocine produced a 3-fold rightward shift in the speedball (3:1 cocaine-heroin combination) dose-effect curve. Food-maintained responding was similar during treatment with saline and with flupenthixol + quadazocine combinations. These findings suggest that medication mixtures designed to target both the stimulant and opioid component of the speedball combination, may be an effective approach to polydrug abuse treatment. (+info)
The role of alcohol abuse in the etiology of heroin-related deaths. Evidence for pharmacokinetic interactions between heroin and alcohol.
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In order to evaluate pharmacokinetic interactions between heroin and alcohol and their role in the etiology of heroin-related deaths (HRD), the alcohol concentration in blood (BAC), the free (FM) and total morphine (TM) concentrations in blood (determined by DPC Coat-A-Count radioimmunoassay before and after enzymatic hydrolysis), and the TM concentration in urine and bile (DPC Coat-A-Count after enzymatic hydrolysis) in a population of 39 lethal cases included in the records of the Department of Legal Medicine and Public Health at the University of Pavia from the period January 1997-April 1998 were examined. The cause of death in each case was attributed to either heroin or associated heroin-ethanol intoxication. Cases were arbitrarily divided into two groups according to BAC (low-ethanol group, LE, BAC < or = 1000 mg/L and high-ethanol group, HE, BAC > 1000 mg/L). The differences in the FM and TM concentrations in blood, bile, and urine and in the FM/TM ratios between the two . groups were statistically evaluated (Mann-Whitney U test). A similar statistical evaluation was carried out on data from a previously published study concerning the disposition of heroin and its metabolites (6-acetylmorphine and morphine) in blood and urine in 23 lethal cases attributed to either heroin or heroin and alcohol intoxication. The values of the following variables in the LE and HE groups were compared: FM, TM, and 6-acetylmorphine concentrations in blood (6-AM); the FM/ (FM + 6-AM) ratio; the FM/TM ratio; and the urinary concentrations of heroin, 6-acetylmorphine, and free morphine. Statistical analyses of data indicated that high BACs are associated with reduced hydrolysis of 6-AM to morphine (FM/[FM + 6-AM], p = 0.0022) and that a good inverse correlation exists between BAC and hydrolysis of 6-AM to morphine (r2 = 0.67). High BACs were also found to be associated with an increased FM/TM ratio and with reduced excretion of free and total morphine. These results suggest the hypothesis that pharmacokinetic interactions between heroin and alcohol do occur in individuals exposed to high doses of these substances. (+info)
Rhabdomyolysis and acute renal failure resulting from alcohol and drug abuse.
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Rhabdomyolysis is a common cause of acute renal failure (ARF) associated with drug misuse. Abuse of the gel formulation of temazepam has been a particular problem in the West of Scotland. We performed a retrospective review of dialysis-dependent ARF from rhabdomyolysis and drug misuse in the West of Scotland, 1986-1997. We identified 76 patients, of whom 87% were male. Seventeen cases occurred in the first 6 years, compared with 59 in the subsequent 6 years. Median age was 32. Thirty cases followed intravenous drug misuse, 46 followed oral drug misuse. The substances most frequently misused were alcohol (54%), heroin (24%) and parenteral temazepam (17%). The temazepam cases all followed the introduction of the gel formulation. Three out of 4 patients requiring limb amputation had injected temazepam. Of intravenous drug misusers tested, 72% were hepatitis-C-positive. Some 43% of patients had deprivation scores in the worst category. ARF due to rhabdomyolysis from substance misuse is increasing in our area. Alcohol is frequently responsible. The introduction of the gel formulation of temazepam has contributed to the increase. Those at risk in this study were young, male, had a high incidence of hepatitis C and lived in the most deprived areas. (+info)
Unusual consequences of heroin overdose: rhabdomyolysis, acute renal failure, paraplegia and hypercalcaemia.
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A 29-yr-old man, known to be a heroin addict, was found at home totally unrousable, bent on his hips in the lotus position. On admission, he required frequent ventricular defibrillation, external pacing and infusion of calcium. A diagnosis of rhabdomyolysis caused by heroin and cocaine overdose was made. He developed paraplegia below T12, acute renal failure, acute compartment syndrome in one leg and a coagulation defect. Despite a fasciotomy, a through-knee amputation of the leg was required. Haemodialysis was required for 26 days, and this period was complicated by increased serum calcium concentrations, which was treated with disodium pamindrate. Calcium deposits were palpable in the muscles and could be seen in vessels on limb x-rays. After 34 days, he was eventually discharged to a general surgical ward and subsequently into the community. (+info)
Can methadone maintenance for heroin-dependent patients retained in general practice reduce criminal conviction rates and time spent in prison?
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A retrospective analysis was made of the criminal records of 57 patients successfully retained in methadone maintenance at two general practices in Sheffield. Their criminal conviction rates and time spent in prison per year were compared for the periods before and after the start of their methadone programme. Overall, patients retained on methadone programmes in the general practices studied had significantly fewer convictions and cautions, and spent significantly less time in prison than they had before the start of treatment. (+info)
Office-based methadone prescribing: acceptance by inner-city practitioners in New York.
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In the US, methadone maintenance is restricted by federal and state regulations to large specialized clinics that serve fewer than 20% of the heroin-dependent population. In Europe, Canada, and Australia, primary health care providers already are utilized widely as methadone prescribers. In preparation for a limited study of office-based methadone treatment in New York City, 71 providers from 11 sites were surveyed about their willingness to prescribe methadone in their office-based practices. Of the 71, 85% had methadone-maintained patients who came to their practice for other care. One-third felt knowledgeable enough to prescribe methadone, and 66% said they would if given proper training and support (88% among AIDS care providers). Half expressed concern that they might be unable to meet the multiple needs of these patients. With additional training and ancillary support, the 47 providers willing to become methadone providers could serve, at 10-20 patients each, 470-940 patients, a population the size of 3-5 average methadone clinics. (+info)
Substance abuse and the kidney.
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Substance abuse has been increasing steadily in the UK and some other countries. Recent evidence suggests more than 40% of young people have tried illicit drugs at some time. There are numerous medical consequences to recreational drug use, and a physician should always consider substance abuse in any unexplained illness. The renal complications of drug abuse are also becoming more frequent, and may encompass a spectrum of glomerular, interstitial and vascular diseases. Although some substances are directly nephrotoxic, a number of other mechanisms are also involved. These effects are often chronic and irreversible, but occasionally acute with possible recovery. The rapid growth of illicit drug use is clearly a major public health problem. We review the commonly used substances of abuse and their associations with renal disease. (+info)
Effects of compounding drug-related stimuli: escalation of heroin self-administration.
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Previous experiments have demonstrated that presenting independently established discriminative stimuli in compound can substantially increase operant responding maintained by food reinforcement or shock avoidance. Recently, this phenomenon was also shown to occur with cocaine self-administration. The present study further assessed the generality of these stimulus-compounding effects by systematically replicating them with heroin self-administration. Rats' nose-poke responses produced intravenous heroin (0.025 mg/kg per infusion) on a variable-ratio schedule when either a tone or a light was present. In the absence of these stimuli, responding was not reinforced. Once discriminative control by the tone and light had been established, the stimuli were presented in compound under extinction (with heroin discontinued) or maintenance conditions (with heroin available during test-stimulus presentations). In extinction, the tone-light compound increased responding approximately threefold compared to tone or light alone. Under maintenance conditions, compounding increased heroin intake approximately twofold. These effects closely matched those obtained earlier with cocaine. This consistency across pharmacological classes and across drug and nondrug reinforcers further confirms that (a) self-administered drugs support conditioning and learning in a manner similar to that supported by other reinforcers; and (b) multiple drug-related cues interact in lawful and predictable ways to affect drug seeking and consumption. (+info)