Ibogaine for treating drug dependence. What is a safe dose?

The indole alkaloid ibogaine, present in the root bark of the West African rain forest shrub Tabernanthe iboga, has been adopted in the West as a treatment for drug dependence. Treatment of patients requires large doses of the alkaloid to cause hallucinations, an alleged integral part of the patient's treatment regime. However, case reports and case series continue to describe evidences of ataxia, gastrointestinal distress, ventricular arrhythmias and sudden and unexplained deaths of patients undergoing treatment for drug dependence. High doses of ibogaine act on several classes of neurological receptors and transporters to achieve pharmacological responses associated with drug aversion; limited toxicology research suggests that intraperitoneal doses used to successfully treat rodents, for example, have also been shown to cause neuronal injury (purkinje cells) in the rat cerebellum. Limited research suggests lethality in rodents by the oral route can be achieved at approximately 263mg/kg body weight. To consider an appropriate and safe initial dose for humans, necessary safety factors need to be applied to the animal data; these would include factors such as intra- and inter-species variability and for susceptible people in a population (such as drug users). A calculated initial dose to treat patients could be approximated at 0.87mg/kg body weight, substantially lower than those presently being administered to treat drug users. Morbidities and mortalities will continue to occur unless practitioners reconsider doses being administered to their susceptible patients.

An Infection Control Programme in Primary Schools and the Wider Public Health Impact

Young schoolchildren are recognised as being at particular risk of contracting and transmitting enteric infection. (Finn and Crook, 1998/1999).

A collaborative infection control programme was designed, piloted and evaluated in six primary schools in conjunction with the local authority's public protection and education departments and the local health protection team. These pilots helped to inform the programme rolled out to all primary and special needs schools during 2002 to 2003.

A baseline sanitation survey was undertaken with the scores used to prioritise schools for infection control audits. High priority schools were audited. Medium and low priority schools were sent self-assessment packs, the results of which were subsequently validated.

Risks were communicated to each school at the time of visit with a follow-up written report. All schools received advice and support on infection control, including recommendations for improvements, updated policies and supporting educational materials.

Key findings from the programme were lack of adequate facilities for handwashing such as soap, paper towels and hot water; ineffective cleaning programmes and working practices, including awareness of Control of Substances Hazardous to Health (COSHH) (1999) and waste disposal.

Infection control guidelines have been produced for schools, together with an ongoing programme of infection control follow-up audits.

Delayed seizure-like activity following analytically confirmed use of previously unreported synthetic cannabinoid analogues

Synthetic cannabinoid use has become widespread, leading to increased burdens on health care providers. Symptoms range from agitation and psychosis to seizures and acute kidney injury. We report a case where a patient was assessed and treated twice within 12 h for seizures following synthetic cannabinoid intoxication. Blood sample determinations showed low concentrations of analogues not previously reported, some of which are legal. Clinicians should be aware that synthetic cannabinoids may cause an array of severe health consequences. Given the ever evolving structure of available analogues, clinicians must also be prepared for other unexpected adverse effects.

Riot control agents: the tear gases CN, CS and OC-a medical review

INTRODUCTION

2-Chloroacetophenone (CN), o-chlorobenzylidene malonitrile (CS) and oleoresin capsicum (OC) are common riot control agents. While serious systemic effects are uncommon, exposure to high concentrations may lead to severe complications and even death. The aim of this narrative review is to summarise all main aspects of the riot control agents CN, CS and OC toxicology, including mechanisms of toxicity, clinical features and management.

METHODS

OVID MEDLINE and ISI Web of Science were searched for terms associated with CN, CS and OC toxicity in humans and those describing the mechanism of action, clinical features and treatment protocols.

RESULTS

CN, CS and OC are effective lacrimating agents; evidence for toxicity, as measured by the threshold for irritation, is greatest for CN, followed by CS and OC. Typically, ocular and respiratory tract irritation occurs within 20-60 s of exposure. Ocular effects involve blepharospasm, photophobia, conjunctivitis and periorbital oedema. Following inhalation, effects may include a stinging or burning sensation in the nose, tight chest, sore throat, coughing, dyspnoea and difficulty breathing. Dermal outcomes are variable, more severe for CN and include dermal irritation, bulla formation and subcutaneous oedema. Removal from the contaminated area and fresh air is a priority. There is no antidote; treatment consists of thorough decontamination and symptom-directed supportive care. Ocular exposure requires thorough eye decontamination, an eye exam and appropriate pain management. Monitoring and support of respiratory function is important in patients with significant respiratory symptoms. Standard treatment protocols may be required with patients with pre-existing respiratory conditions. Dermal exposures may require systemic steroids for patients who develop delayed contact dermatitis.

CONCLUSIONS

CN, CS and OC are effective riot control agents. In the majority of exposures, significant clinical effects are not anticipated. The irritant effects can be minimised both by rapid evacuation from sites of exposure, decontamination and appropriate supportive care.

Benign cardiac tumours: cardiac CT and MRI imaging appearances

Primary benign cardiac tumours are rarely found in clinical practice and are generally evaluated with echocardiography. However, with the increasing usage of helical multislice CT, the initial detection and evaluation of these masses may be made by the radiologist during routine daily practice for other indications. The echocardiographic, CT and cardiac MRI appearances of various benign cardiac tumours and masses are described and illustrated in this review.

Coil embolization of iatrogenic arterio-venous fistula from pulmonary collateral artery to subclavian vein

A young woman with surgically treated tetralogy of Fallot with pulmonary atresia, with multiple aorto-pulmonary collateral arteries, developed an arteriovenous fistula subsequent to transvenous insertion of an automatic implantable defibrillator via the left subclavian vein. The fistula extended between this vein and a systemic-to-pulmonary collateral artery arising from the subclavian artery. Unilateral peau d'orange, and painful congestion of the left arm and breast, ensued. These were cured by coil embolization of a fistula-related aneurysm.

Review of research studies that evaluated the impact of treatment for childhood cancers on neurocognition and behavioral and social competence: nursing implications

ISSUES AND PURPOSE

Given the increasing incidence of childhood cancer, increasing survivor rates, and documented incidence of sequelae, nurses need evidence on which to base interventions for families at risk. The authors review and critique research studies that evaluated the impact of treatment for childhood cancers. Implications for nursing practice are discussed.

CONCLUSIONS

Research to evaluate the effects of treatment on neurocognition and behavioral and social competency of children with cancer has produced conflicting results. Most studies found deleterious effects on all three areas associated with childhood cancer treatment. Some studies, however, found no differences between childhood cancer survivors and children on therapy compared to normative data or healthy controls.

PRACTICE IMPLICATIONS

Knowledge of the short- and long-term impact of treatment for childhood cancer on neurocognition and behavioral and social competence allows nurses to design interventions that mitigate neurocognitive effects, decrease behavioral problems, and improve social competence.

Women's steps of change and entry into drug abuse treatment. A multidimensional stages of change model

The Transtheoretical, or Stages of Change Model, has been applied to the investigation of help-seeking related to a number of addictive behaviors. Overall, the model has shown to be very important in understanding the process of help-seeking. However, substance abuse rarely exists in isolation from other health, mental health, and social problems. The present work extends the original Stages of Change Model by proposing "Steps of Change" as they relate to entry into substance abuse treatment programs for women. Readiness to make life changes in four domains-domestic violence, HIV sexual risk behavior, substance abuse, and mental health-is examined in relation to entry into four substance abuse treatment modalities (12-step, detoxification, outpatient, and residential). The Steps of Change Model hypothesizes that help-seeking behavior of substance-abusing women may reflect a hierarchy of readiness based on the immediacy, or time urgency, of their treatment issues. For example, women in battering relationships may be ready to make changes to reduce their exposure to violence before admitting readiness to seek substance abuse treatment. The Steps of Change Model was examined in a sample of 451 women contacted through a substance abuse treatment-readiness program in Los Angeles, California. A series of logistic regression analyses predict entry into four separate treatment modalities that vary. Results suggest a multidimensional Stages of Change Model that may extend to other populations and to other types of help-seeking behaviors.

Acceptable levels of digital image compression in chest radiology

The introduction of picture archival and communications systems (PACS) and teleradiology has prompted an examination of techniques that optimize the storage capacity and speed of digital storage and distribution networks. The general acceptance of the move to replace conventional screen-film capture with computed radiography (CR) is an indication that clinicians within the radiology community are willing to accept images that have been 'compressed'. The question to be answered, therefore, is what level of compression is acceptable. The purpose of the present study is to provide an assessment of the ability of a group of imaging professionals to determine whether an image has been compressed. To undertake this study a single mobile chest image, selected for the presence of some subtle pathology in the form of a number of septal lines in both costphrenic angles, was compressed to levels of 10:1, 20:1 and 30:1. These images were randomly ordered and shown to the observers for interpretation. Analysis of the responses indicates that in general it was not possible to distinguish the original image from its compressed counterparts. Furthermore, a preference appeared to be shown for images that have undergone low levels of compression. This preference can most likely be attributed to the 'de-noising' effect of the compression algorithm at low levels.

Activation and adoptive transfer of Epstein-Barr virus-specific cytotoxic T cells in solid organ transplant patients with posttransplant lymphoproliferative disease

The treatment of Epstein-Barr virus (EBV)-associated lymphoproliferative disease (PTLD) in EBV seronegative solid organ transplant recipients who acquire their EBV infection after engraftment poses a considerable challenge because of underlying immunosuppression that inhibits the virus-specific cytotoxic T cell (CTL) response in vivo. We have developed a protocol for activating autologous EBV-specific CTL lines from these patients and show their potential use for immunotherapy against PTLD in solid organ transplant patients. Peripheral blood mononuclear cells from a panel of solid organ transplant recipients with and without active PTLD were used to assess EBV-specific memory CTL responses. The activation protocol involved cocultivation of peripheral blood mononuclear cells with an autologous lymphoblastoid cell line under conditions that favored expansion of virus-specific CTL and hindered the proliferation of allospecific T cells. These CTL consistently showed (i) strong EBV-specificity, including reactivity through defined epitopes in spite of concurrent immunosuppressive therapy, and (ii) no alloreactivity toward donor alloantigens. More importantly, adoptive transfer of these autologous CTLs into a single patient with active PTLD was coincident with a very significant regression of the PTLD. These results demonstrate that a potent EBV-specific memory response can be expanded from solid organ recipients who have acquired their primary EBV infection under high levels of immunosuppressive therapy and that these T cells may have therapeutic potential against PTLD.

Evaluation of the effects of outreach to women with multiple vulnerabilities on entry into substance abuse treatment

This paper examines ways in which the level of participation in intensive outreach contributes to entry into substance abuse treatment. It was hypothesized that the number of outreach contacts to substance abusing women predicts the likelihood of their entry into drug abuse treatment. As such women often have multiple vulnerabilities that impact upon their needs and readiness for seeking treatment, we also examine the relationships among readiness to seek assistance, the women's level of involvement with the outreach project, and admission to treatment. A sample of 665 women who participated in an enhanced outreach and treatment readiness preparation program was tracked to examine patterns of referral and entry into substance abuse treatment. The number of outreach contacts was inversely related to receiving referrals to substance abuse treatment, as well as to the completion of those referrals (for a subsample of 551 women who had received referrals). In addition, victims of domestic violence were 50% more likely to receive a referral to drug abuse treatment, but of the women who received such a referral, the lack of involvement in a violent relationship predicted entry into treatment. Findings are discussed in terms of their implications for designing and implementing outreach and treatment programs for women with multiple therapeutic issues, particularly substance abuse and domestic violence.

Scorpion toxins as tools for studying potassium channels

The search for peptidyl inhibitors of K+ channels is a very active area of investigation. In addition to scorpion venoms, other venom sources have been investigated; all of these sources have yielded novel peptides with interesting properties. For instance, spider venoms have provided peptides that block other families of K+ channels (e.g., Kv2 and Kv4) that act via mechanisms which modify the gating properties of these channels. Such inhibitors bind to a receptor on the channel that is different from the pore region in which the peptides discussed in this chapter bind. In fact, it is possible to have a channel occupied simultaneously by both inhibitor types. It is expected that many of the methodologies concerning peptidyl inhibitors from scorpion venom, which have been developed in the past and outlined above, will be extended to the new families of K+ channel blockers currently under development.

Dimensions of health-related quality of life in persons living with HIV disease

The purpose of this secondary analysis was to test empirically the influence of biological and physiological variables, symptom status, functional status, general health perceptions, characteristics of the individual and characteristics of the environment on overall quality of life in persons living with HIV disease. Path analysis, using multiple linear regression, was used to examine the fit between a health-related quality of life (HRQOL) theoretical model and data from a sample of 142 persons with an AIDS diagnosis. Thirty-two per cent of the variance in overall quality of life was explained by the HRQOL model with symptom status having the greatest influence (beta = -0.237, R2(Y x 2) = 5%). This analysis suggests that symptom status, functional status and general health perceptions are key dimensions of HRQOL. With a focus on prevention, health promotion, symptom management, and the alleviation of acute and chronic illness effects, HRQOL may be appropriate for capturing the outcomes of nursing interventions.

Thrombosis of a mechanical tricuspid valve prosthesis and of the left subclavian vein: successful therapy with thrombolysis

A patient with thrombosis of a mechanical prosthetic valve in the tricuspid position, simultaneous extensive left subclavian vein thrombotic occlusion, and pulmonary embolism is successfully treated with a urokinase infusion delivered using catheter-based techniques.

Blockade of the voltage-gated potassium channel Kv1.3 inhibits immune responses in vivo

The voltage activated K+ channel (Kv1.3) has recently been identified as the molecule that sets the resting membrane potential of peripheral human T lymphoid cells. In vitro studies indicate that blockage of Kv1.3 inhibits T cell activation, suggesting that Kv1.3 may be a target for immunosuppression. However, despite the in vitro evidence, there has been no in vivo demonstration that blockade of Kv1.3 will attenuate an immune response. The difficulty is due to species differences, as the channel does not set the membrane potential in rodent peripheral T cells. In this study, we show that the channel is present on peripheral T cells of miniswine. Using the peptidyl Kv1.3 inhibitor, margatoxin, we demonstrate that Kv1.3 also regulates the resting membrane potential, and that blockade of Kv1.3 inhibits, in vivo, both a delayed-type hypersensitivity reaction and an Ab response to an allogeneic challenge. In addition, prolonged Kv1.3 blockade causes reduced thymic cellularity and inhibits the thymic development of T cell subsets. These results provide in vivo evidence that Kv1.3 is a novel target for immunomodulation.

Blockade of the voltage-gated potassium channel Kv1.3 inhibits immune responses in vivo

The voltage activated K+ channel (Kv1.3) has recently been identified as the molecule that sets the resting membrane potential of peripheral human T lymphoid cells. In vitro studies indicate that blockage of Kv1.3 inhibits T cell activation, suggesting that Kv1.3 may be a target for immunosuppression. However, despite the in vitro evidence, there has been no in vivo demonstration that blockade of Kv1.3 will attenuate an immune response. The difficulty is due to species differences, as the channel does not set the membrane potential in rodent peripheral T cells. In this study, we show that the channel is present on peripheral T cells of miniswine. Using the peptidyl Kv1.3 inhibitor, margatoxin, we demonstrate that Kv1.3 also regulates the resting membrane potential, and that blockade of Kv1.3 inhibits, in vivo, both a delayed-type hypersensitivity reaction and an Ab response to an allogeneic challenge. In addition, prolonged Kv1.3 blockade causes reduced thymic cellularity and inhibits the thymic development of T cell subsets. These results provide in vivo evidence that Kv1.3 is a novel target for immunomodulation.

Pharmacists' ability to influence outcomes of hypertension therapy

We measured the impact of pharmaceutical care on outcomes of antihypertensive therapy for patients with elevated baseline blood pressures who were attending an urban university-affiliated internal medicine clinic. The intervention group received education about hypertension, drug and nondrug management, and assistance to enhance compliance. The pharmacist made recommendations to physicians regarding pharmacotherapy. The control group received no such education, and interventions relating to pharmacotherapy were only physician initiated. Over an average follow-up of 5 months, significant-decreases in mean blood pressures were noted for the intervention group from baseline to final assessment (156.5/144.5 mm Hg systolic, p = 0.001; 91.6/86.9 mm Hg diastolic, p = 0.01), with insignificant changes in mean pressures in the control group (153.7/151.0 mm Hg systolic, p = 0.48; 90.4/87.8 mm Hg diastolic, p = 0.29). Comparing the groups, the change in diastolic pressures was insignificant (4.7 vs 2.6 mm Hg intervention vs control, p = 0.49), but the change in systolic pressure was more impressive (12.0 vs 2.7 mm Hg, respectively, p = 0.05). There was no significant difference in SF-36 Health Survey scores between groups. A significant decrease (p = 0.03) in the SF-36 physical functioning domain was seen in the intervention group, but no other significant changes in health-related quality of life scores. Pharmaceutical care contributed to improved blood pressure control in these patients.

Wound care practices in the United States

Wound management is a crucial aspect of patient care and the nurse often is faced with the question of which approaches to use to provide an environment that supports healing and prevents complications. Important questions include how different types of wounds should be dressed, what method of debridement to use, whether dressings should be changed using sterile versus unsterile technique, and which adjunctive therapies to select under given circumstances. These topics are of interest to clinicians as they represent actual clinical practice and some of the major debates among health care providers who are trying to determine which practices to use to optimize wound healing. While studies are available that compare specific products, no data are available at this time regarding the current wound care practices in the United States. If data documenting the existing wound care practices were available, they would increase understanding of how other professionals manage wound care and provide the basis for planning patient care as well as educational programs and research on wound care.

Paraneoplastic vasculitic neuropathy: a treatable neuropathy

Paraneoplastic vasculitic neuropathy has been recently described. We report the first case of this disorder which responded both clinically and electrophysiologically to cyclophosphamide treatment. A 54-year-old woman with a history of metastatic endometrial carcinoma in remission had asymmetrical polyneuropathy, electrophysiological findings consistent with a diffuse axonal neuropathy, high sedimentation rate and spinal fluid protein, and microvasculitis with axonal degeneration on nerve biopsy. The patient was treated with 150 mg of cyclophosphamide daily with gradual clinical and electrophysiological improvement.

Evaluation of two methods for estimating theophylline clearance prior to achieving steady state

The Koup et al. and Chiou et al. clearance estimation methods were evaluated n 19 chronic obstructive pulmonary disease (COPD)/asthmatic patients who were receiving aminophylline by continuous infusion. Estimated theophylline clearance (Clest) was determined using two serum concentrations obtained during the first few hours of therapy (1-16 hr) prior to achievement of steady state. Actual theophylline clearance (Clact) was determined after steady state conditions had been achieved (defined as 4-5 half-lives at the same infusion rate). The correlation between Clact and Clest was highly significant for both the Koup et al. and Chiou et al. methods, r = 0.865, p less than 0.001, and r = 0.858, p less than 0.001, respectively. The clearance estimation methods were compared with the Food and Drug Administration (FDA) dosage guidelines and shown to be clearly superior in predicting therapeutic steady state theophylline concentrations.

Suspected malabsorption of aminophylline in pancreatis

The case of a patient with pancreatitis in whom low theophylline concentrations were observed on oral aminophylline is presented. Therapeutic theophylline concentrations were obtained with intravenous aminophylline. However, serum levels following oral doses were only 20 to 40% of those observed with intravenous administration, suggesting malabsorption. The most reasonable explanation for this was the patient's pancreatic dysfunction, since adequate absorption of oral aminophylline had been demonstrated on a previous admission not associated with pancreatis, and other possible causes of malabsorption were ruled out.

Mechanisms of nonlinear disposition kinetics of sulfamethazine

Five healthy male subjects received oral doses of 10 and 40 mg/kg of sulfamethazine (SMZ) approximately 14 days apart in a nonrandomized crossover study. Blood and urine samples were collected for at least 24 and 72 hr, respectively. All samples were assayed by the Bratton-Marshall procedure for SMZ and apparent N-acetylsulfamethazine (NSMZ). Recovery of total drug (SMZ + NSMZ) in urine was 88.9% following the low and 79.5% following the high dose. The low and high dose plasma concentration time curves were not readily superimposable (i.e., nonlinear kinetic behavior was observed). The data suggest that several mechanisms contribute to the nonlinearity. Specifically, a dose-dependent decrease in absorption rate displaced the plasma concentration-time curve to the right in some subjects, whereas apparent metabolic clearance (Clm) decreased with increasing dose (estimated assuming dose = amount of SMZ + NSMZ in urine to 72 hr) in all subjects (0.35 ml/min/kg for the low and 0.23 for the high dose). Still greater dose-dependent effects were found when apparent Clm of unbound drug was determined, since free fraction rose from 0.11 to 0.30 over the observed plasma concentration range. Renal clearance (ClR) of Smz appeared to be a complex function of time. In the low dose study it ranged from an average of 0.071 ml/min/kg at 2 hr to 0.146 ml/min/kg at 6 hr after drug. After the high dose comparable values were 0.083 and 0.128. Interindividual variability and pronounced nonlinear kinetics of SMZ after 40 mg/kg suggest that this dose is probably a poor choice for the determination of acetylator phenotype.