Pentamidine-induced derangements of glucose homeostasis. Determinant roles of renal failure and drug accumulation. A study of 128 patients

Drug-induced hyperglycemia and diabetes

BACKGROUND

Drug-induced hyperglycemia and diabetes have negative and potentially serious health consequences but can often be unnoticed.

METHODS

We reviewed the literature searching Medline database for articles addressing drug-induced hyperglycemia and diabetes up to January 31, 2023. We also selected drugs that could induce hyperglycemia or diabetes according official data from drug information databases Thériaque and Micromedex. For each selected drug or pharmacotherapeutic class, the mechanisms of action potentially involved were investigated. For drugs considered to be at risk of hyperglycemia or diabetes, disproportionality analyses were performed using data from the international pharmacovigilance database VigiBase. In order to detect new pharmacovigilance signals, additional disproportionality analyses were carried out for drug classes with more than 100 cases reported in VigiBase, but not found in the literature or official documents.

RESULTS

The main drug classes found to cause hyperglycemia are glucocorticoids, HMG-coA reductase inhibitors, thiazide diuretics, beta-blockers, antipsychotics, fluoroquinolones, antiretrovirals, antineoplastic agents and immunosuppressants. The main mechanisms involved are alterations in insulin secretion and sensitivity, direct cytotoxic effects on pancreatic cells and increases in glucose production. Pharmacovigilance signal were found for a majority of drugs or pharmacological classes identified as being at risk of diabetes or hyperglycemia. We identified new pharmacovigilance signals with drugs not known to be at risk according to the literature or official data: phosphodiesterase type 5 inhibitors, endothelin receptor antagonists, sodium oxybate, biphosphonates including alendronic acid, digoxin, sartans, linosipril, diltiazem, verapamil, and darbepoetin alpha. Further studies will be needed to confirm these signals.

CONCLUSIONS

The risks of induced hyperglycemia vary from one drug to another, and the underlying mechanisms are multiple and potentially complex. Clinicians need to be vigilant when using at-risk drugs in order to detect and manage these adverse drug reactions. However, it is to emphasize that the benefits of appropriately prescribed treatments most often outweigh their metabolic risks.

Medication-induced hyperglycemia: pediatric perspective

Medication-induced hyperglycemia is a frequently encountered clinical problem in children. The intent of this review of medications that cause hyperglycemia and their mechanisms of action is to help guide clinicians in prevention, screening and management of pediatric drug-induced hyperglycemia. We conducted a thorough literature review in PubMed and Cochrane libraries from inception to July 2019. Although many pharmacotherapies that have been associated with hyperglycemia in adults are also used in children, pediatric-specific data on medication-induced hyperglycemia are scarce. The mechanisms of hyperglycemia may involve β cell destruction, decreased insulin secretion and/or sensitivity, and excessive glucose influx. While some medications (eg, glucocorticoids, L-asparaginase, tacrolimus) are markedly associated with high risk of hyperglycemia, the association is less clear in others (eg, clonidine, hormonal contraceptives, amiodarone). In addition to the drug and its dose, patient characteristics, such as obesity or family history of diabetes, affect a child's risk of developing hyperglycemia. Identification of pediatric patients with increased risk of developing hyperglycemia, creating strategies for risk reduction, and treating hyperglycemia in a timely manner may improve patient outcomes.

Consecutive hypoglycemia attacks induced by co-trimoxazole followed by pentamidine in a patient with acquired immunodeficiency syndrome

Both co-trimoxazole and pentamidine are used for the treatment of pneumocystis pneumonia (PCP) and are known to cause hypoglycemia as an adverse drug reaction. Here, we describe a rare case of a late-diagnosed female patient with acquired immunodeficiency syndrome (AIDS) who developed the first hypoglycemic attack as an adverse effect of co-trimoxazole, followed by a second hypoglycemic attack as an adverse effect of pentamidine. Physicians caring for patients with AIDS and PCP should be aware of possible hypoglycemia in patients with many risk factors.

Treatment of Pneumocystis jirovecii pneumonia in HIV-infected patients: a review

INTRODUCTION

Pneumocystis pneumonia is a potentially life-threatening pulmonary infection that occurs in immunocompromised individuals and HIV-infected patients with a low CD4 cell count. Trimethoprim-sulfamethoxazole has been used as the first-line agent for treatment, but mutations within dihydropteroate synthase gene render potential resistance to sulfamide. Despite advances of combination antiretroviral therapy (cART), Pneumocystis pneumonia continues to occur in HIV-infected patients with late presentation for cART or virological and immunological failure after receiving cART. Areas covered: This review summarizes the diagnosis and first-line and alternative treatment and prophylaxis for Pneumocystis pneumonia in HIV-infected patients. Articles for this review were identified through searching PubMed. Search terms included: 'Pneumocystis pneumonia', 'Pneumocystis jirovecii pneumonia', 'Pneumocystis carinii pneumonia', 'trimethoprim-sulfamethoxazole', 'primaquine', 'trimetrexate', 'dapsone', 'pentamidine', 'atovaquone', 'echinocandins', 'human immunodeficiency virus infection', 'acquired immunodeficiency syndrome', 'resistance to sulfamide' and combinations of these terms. We limited the search to English language papers that were published between 1981 and March 2017. We screened all identified articles and cross-referenced studies from retrieved articles. Expert commentary: Trimethoprim-sulfamethoxazole will continue to be the first-line agent for Pneumocystis pneumonia given its cost, availability of both oral and parenteral formulations, and effectiveness or efficacy in both treatment and prophylaxis. Whether resistance due to mutations within dihydropteroate synthase gene compromises treatment effectiveness remains controversial. Continued search for effective alternatives with better safety profiles for Pneumocystis pneumonia is warranted.

The global diabetes epidemic: what does it mean for infectious diseases in tropical countries?

Tropical countries are experiencing a substantial rise in type 2 diabetes, which is often undiagnosed or poorly controlled. Since diabetes is a risk factor for many infectious diseases, this increase probably adds to the large infectious disease burden in tropical countries. We reviewed the literature to investigate the interface between diabetes and infections in tropical countries, including the WHO-defined neglected tropical diseases. Although solid data are sparse, patients with diabetes living in tropical countries most likely face increased risks of common and health-care-associated infections, as well as infected foot ulcers, which often lead to amputation. There is strong evidence that diabetes increases the severity of some endemic infections such as tuberculosis, melioidosis, and dengue virus infection. Some HIV and antiparasitic drugs might induce diabetes, whereas helminth infections appear to afford some protection against future diabetes. But there are no or very scarce data for most tropical infections and for possible biological mechanisms underlying associations with diabetes. The rise in diabetes and other non-communicable diseases puts a heavy toll on health systems in tropical countries. On the other hand, complications common to both diabetes and some tropical infections might provide an opportunity for shared services-for example, for eye health (trachoma and onchocerciasis), ulcer care (leprosy), or renal support (schistosomiasis). More research about the interaction of diabetes and infections in tropical countries is needed, and the infectious disease burden in these countries is another reason to step up global efforts to improve prevention and care for diabetes.

Meglumine antımoniate-TiO2@Ag nanoparticle combinations reduce toxicity of the drug while enhancing its antileishmanial effect

Currently, the treatment of leishmaniasis is increasingly insufficient as current antileishmanial drugs have many disadvantages such as toxic side effects, high cost, and growing drug resistance. In order to overcome these disadvantages, researchers have recently focused on combination therapy by using pentavalent antimonials in conjunction with other antileihmanial compounds. Our previous study found that TiO2@Ag nanoparticles (TiAgNps) demonstrated significant antileishmanial effects. However, a lethal dose of TiAgNps on L. topica promastigotes was found to be toxic for macrophage cells. Moreover, non-toxic concentrations of TiAgNps were ineffective in inhibiting L. topica promastigotes and amastigotes. Thus, we propose the use of TiAgNps in combination with other antileishmanial compounds like meglumine antimoniate (MA) at non-toxic concentrations, which may increase the efficacies of both agents and decrease their toxicities. Therefore, the aim of this study was to determine in vitro and in vivo antileishmanial efficacies of TiAgNps-MA combinations at non-toxic concentrations and develop a new approach for treatment that lowers the toxicities of pentavalent antimonials to minimal levels and enhances their effectiveness. In vitro screening was performed on L. topica promastigote and amastigote-macropage culture by using MTT assay to determine proliferation, perform infection index analysis, and to conduct a Griess reaction for nitric oxide production, while in vivo antileishmanial assays were applied on Balb/c mice with CL models. The results demonstrated that combinations including TiAgNps and MA at non-toxic concentrations were highly efficacious against both promastigotes and amastigotes, while MA application alone did not show any inhibitory effects. It was determined that combination applications decreased the proliferation of L. topica promastigotes 2- to 5-fold in contrast to use of MA alone, and was dependent on concentrations. Moreover, the use of combinations led to inhibition of L. topica amastigotes at rates ranging between 80% and 95%. Additionally, combinations were found to decrease metabolic activities of each form of the parasite at ranges between 7- to 20-fold, causing programmed-cell death and stimulation of macrophages for intensive production of nitric oxide, which is accepted as an important antileishmanial agent (p<0.05). Furthermore, Σ FIC analysis demonstrated that the tested combinations composed little additive, but mostly synergistic effects for inhibition of promastigotes and amastigotes. According to in vivo screening results, the combinations displayed high antileishmanial activities by successfully healing lesions and significantly reducing parasite burdens. Combined, these results show that TiAgNps-MA combinations were much more effective than use of MA alone at non-toxic concentrations and they possess high potential for development of new antileishmanial drugs to fight against leishmaniasis.

Current clinical, laboratory, and treatment outcome characteristics of visceral leishmaniasis: results from a seven-year retrospective study in Greece

OBJECTIVES

Visceral leishmaniasis (VL) is re-emerging in endemic areas. The epidemiological, clinical, laboratory, and treatment outcome characteristics in a large cohort of VL patients is described herein.

METHODS

The cases of 67 VL patients (57% male, mean age 56 years) treated in two Greek hospitals over the last 7 years were identified and evaluated retrospectively.

RESULTS

Forty-six percent of patients reported contact with animals. Seventeen patients (25%) were immunocompromised, and 22% were co-infected with another pathogen. Sixty-four percent of patients had fever, 57% had weakness, 37% had sweats, 21% had weight loss, and 13% had a dry cough, while 6% developed haemophagocytic syndrome. The median duration of symptoms was 28 days. Fifty-eight percent of patients had splenomegaly, 49% had hepatomegaly, and 36% had lymphadenopathy. The diagnosis was established by positive PCR in peripheral blood (73%) and/or bone marrow specimens (34%). Sixty-one patients (91%) received liposomal amphotericin (L-AMB). Six patients (10%) did not respond or relapsed but were eventually cured after a second cycle of L-AMB. During a 6-month follow-up, the overall mortality was 9%, although none of these deaths was attributed to VL.

CONCLUSIONS

VL is still a common disease in endemic areas, affecting immunocompetent and immunocompromised patients. Its diagnosis is challenging, and molecular techniques are valuable and helpful tools to achieve this. Treatment with L-AMB is safe and very effective.

Contemporary review of drug-induced pancreatitis: A different perspective

Although gallstone and alcohol use have been considered the most common causes of acute pancreatitis, hundreds of frequently prescribed medications are associated with this disease state. The true incidence is unknown since there are few population based studies available. The knowledge of drug induced acute pancreatitis is limited by the availability and the quality of the evidence as the majority of data is extrapolated from case reports. Establishing a definitive causal relationship between a drug and acute pancreatitis poses a challenge to clinicians. Several causative agent classification systems are often used to identify the suspected agents. They require regular updates since new drug induced acute pancreatitis cases are reported continuously. In addition, infrequently prescribed medications and herbal medications are often omitted. Furthermore, identification of drug induced acute pancreatitis with new medications often requires accumulation of post market case reports. The unrealistic expectation for a comprehensive list of medications and the multifactorial nature of acute pancreatitis call for a different approach. In this article, we review the potential mechanisms of drug induced acute pancreatitis and provide the perspective of deductive reasoning in order to allow clinicians to identify potential drug induced acute pancreatitis with limited data.

17-AAG kills intracellular Leishmania amazonensis while reducing inflammatory responses in infected macrophages

Background

Leishmaniasis is a neglected endemic disease with a broad spectrum of clinical manifestations. Pentavalent antimonials have been the treatment of choice for the past 70 years and, due to the emergence of resistant cases, the efficacy of these drugs has come under scrutiny. Second-line drugs are less efficacious, cause a range of side effects and can be costly. The formulation of new generations of drugs, especially in developing countries, has become mandatory.

Methodology/Principal Findings

We investigated the anti-leishmanial effect of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, in vitro. This inhibitor is currently in clinical trials for cancer treatment; however, its effects against intracellular Leishmania remain untested. Macrophages infected with L. amazonensis were treated with 17-AAG (25–500 nM) and parasite load was quantified using optical microscopy. Parasite load declined in 17-AAG-treated macrophages in a dose- and time-dependent manner. Intracellular parasite death became irreversible after 4 h of treatment with 17-AAG, and occurred independent of nitric oxide (NO) and superoxide (O₂⁻) production. Additionally, intracellular parasite viability was severely reduced after 48 h of treatment. Interestingly, treatment with 17-AAG reduced pro-inflammatory mediator production, including TNF-α, IL-6 and MCP-1, yet IL-12 remained unaffected. Electron microscopy revealed morphological alterations, such as double-membrane vacuoles and myelin figures at 24 and 48 h after 17-AAG treatment.

Conclusions/Significance

The HSP90 inhibitor, 17-AAG, possesses high potency under low dosage and reduces both pro-inflammatory and oxidative molecule production. Therefore, further studies are warranted to investigate this inhibitor’s potential in the development of new generations of anti-leishmanials.

Effect of cimetidine on pentamidine induced hyperglycemia in rats

The antiprotozoal agent pentamidine, used for the treatment of Pneumocystis jirovecii pneumonia (PCP), is known to cause abnormalities in blood glucose homeostasis, such as hypoglycemia and hyperglycemia. Pentamidine has been reported to be a substrate of organic cation transporter 1 (OCT1). We investigated the combination effects of cimetidine, an OCT1 inhibitor, on the pharmacokinetics of pentamidine and on pentamidine-induced hyperglycemia. Pentamidine was infused intravenously to rats for 20 min at a dose of 7.5 or 15 mg/kg and serum samples were obtained periodically. The serum concentration of glucose did not change significantly after pentamidine infusion at 7.5mg/kg, while it increased with pentamidine at 15 mg/kg, and the maximal concentration of glucose was 167 ± 36 mg/dl, 30 min after the start of pentamidine infusion. Cimetidine (50mg/kg) enhanced the pentamidine-induced elevation of glucose concentration and the maximal concentration of glucose was 208 ± 33 mg/dl in the pentamidine 15 mg/kg treated group. Cimetidine combination significantly reduced total body clearance of pentamidine and increased pentamidine concentrations in the liver, kidneys, and lungs. A significant correlation was found between changes in serum glucose concentrations and serum concentrations of pentamidine 30 min after the start of pentamidine infusion. These results suggest that the hyperglycemic effect of pentamidine is dependent on the concentration of pentamidine and can be enhanced by cimetidine combination.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Pharmacophore model for pentamidine analogs active against Plasmodium falciparum

Pentamidine and its analogs constitute a class of compounds that are known to be active against Plasmodium falciparum, which causes the most dangerous malarial infection. Malaria is a widespread disease known to affect hundreds of millions of people and presents a perceivable threat of spreading. Hence, there is a need for well-defined scaffolds that lead to new, effective treatment. Here we present a pentamidine-based pharmacophore constructed using GALAHAD that would aid targeted synthesis of leads with enhanced properties, as well as the development of lead scaffolds. The study was supported by high-quality biological in vitro data of 22 compounds against the P. falciparum strains NF54 and K1. The model established reveals the importance of hydrophobic phenyl rings with polar oxygen and amidine substituents and the hydrophobic linking chain for the activity against malaria.

Drug-induced endocrine disorders in the intensive care unit

The neuroendocrine response to critical illness is key to the maintenance of homeostasis. Many of the drugs administered routinely in the intensive care unit significantly impact the neuroendocrine system. These agents can disrupt the hypothalamic-pituitary-adrenal axis, cause thyroid abnormalities, and result in dysglycemia. Herein, we review major drug-induced endocrine disorders and highlight some of the controversies that remain in this area. We also discuss some of the more rare drug-induced syndromes that have been described in the intensive care unit. Drugs that may result in an intensive care unit admission secondary to an endocrine-related adverse event are also included. Unfortunately, very few studies have systematically addressed drug-induced endocrine disorders in the critically ill. Timely identification and appropriate management of drug-induced endocrine adverse events may potentially improve outcomes in the critically ill. However, more research is needed to fully understand the impact of medications on endocrine function in the intensive care unit.

Anemia causes hypoglycemia in intensive care unit patients due to error in single-channel glucometers: methods of reducing patient risk

OBJECTIVE

Intensive insulin therapy in the critically ill reduces mortality but carries the risk of increased hypoglycemia. Point-of-care blood glucose analysis is standard; however, anemia causes falsely high values and potentially masks hypoglycemia. Permissive anemia is practiced routinely in most intensive care units. We hypothesized that point-of-care glucometer error due to anemia is prevalent, can be corrected mathematically, and correction uncovers occult hypoglycemia during intensive insulin therapy.

DESIGN

The study has both retrospective and prospective phases. We reviewed data to verify the presence of systematic error, determine the source of error, and establish the prevalence of anemia. We confirmed our findings by reproducing the error in an in vitro model. Prospective data were used to develop a correction formula validated by the Monte Carlo method. Correction was implemented in a burn intensive care unit and results were evaluated after 9 mos.

SETTING

Burn and trauma intensive care units at a single research institution.

PATIENTS/SUBJECTS

Samples for in vitro studies were taken from healthy volunteers. Samples for formula development were from critically ill patients who received intensive insulin therapy.

INTERVENTIONS

Insulin doses were calculated based on predicted serum glucose values from corrected point-of-care glucometer measurements.

MEASUREMENTS AND MAIN RESULTS

Time-matched point-of-care glucose, laboratory glucose, and hematocrit values. We previously found that anemia (hematocrit <34%) produces systematic error in glucometer measurements. The error was correctible with a mathematical formula developed and validated, using prospectively collected data. Error of uncorrected point-of-care glucose ranged from 19% to 29% (p < .001), improving to < or = 5% after mathematical correction of prospective data. Comparison of data pairs before and after correction formula implementation demonstrated a 78% decrease in the prevalence of hypoglycemia in critically ill and anemic patients treated with insulin and tight glucose control (p < .001).

CONCLUSIONS

A mathematical formula that corrects erroneous point-of-care glucose values due to anemia in intensive care unit patients reduces the prevalence of hypoglycemia during intensive insulin therapy.

Pneumocystis pneumonia in children

Pneumocystis pneumonia (PCP) is a life-threatening infection in immunocompromised children with quantitative and qualitative defects in T lymphocytes. At risk are children with lymphoid malignancies, HIV infection, corticosteroid therapy, transplantation and primary immunodeficiency states. Diagnosis is established through direct examination or polymerase chain reaction (PCR) from respiratory secretions. Trimethoprim-sulphamethoxazole is used for initial therapy in most patients, while pentamidine, atovaquone, clindamycin plus primaquine, and dapsone plus trimethoprim are alternatives. Prophylaxis of high-risk patients reduces but does not eliminate the risk of PCP. Improved understanding of the pathogenesis of PCP is important for future advances against this life-threatening infection.

Drug-Induced Endocrine and Metabolic Disorders

Complex interactions exist amongst the various components of the neuroendocrine system in order to maintain homeostasis, energy balance and reproductive function. These components include the hypothalamus-pituitary- adrenal and -gonadal axes, the renin-angiotensin-aldosterone system, the sympathetic nervous system and the pancreatic islets. These hormones, peptides and neurotransmitters act in concert to regulate the functions of many organs, notably the liver, muscles, kidneys, thyroid, bone, adrenal glands, adipocytes, vasculature, intestinal tract and gonads, through many intermediary pathways. Endocrine and metabolic disorders can arise from imbalance amongst numerous hormonal factors. These disturbances may be due to endogenous processes, such as increased secretion of hormones from a tumour, as well as exogenous drug administration. Drugs can cause endocrine abnormalities via different mechanisms, including direct alteration of hormone production, changes in the regulation of the hormonal axis, effects on hormonal transport, binding, and signalling, as well as similar changes to counter-regulatory hormone systems. Furthermore, drugs can affect the evaluation of endocrine parameters by causing interference with diagnostic tests. Common drug-induced endocrine and metabolic disorders include disorders of carbohydrate metabolism, electrolyte and calcium abnormalities, as well as drug-induced thyroid and gonadal disorders. An understanding of the proposed mechanisms of these drug effects and their evaluation and differential diagnosis may allow for more critical interpretation of the clinical observations associated with such disorders, better prediction of drug-induced adverse effects and better choices of and rationales for treatment.

In vitro selection and in vivo efficacy of piperazine- and alkanediamide-linked bisbenzamidines against Pneumocystis pneumonia in mice

Bisbenzamidines, such as pentamidine isethionate, are aromatic dicationic compounds that are active against Pneumocystis and other microbes but are oftentimes toxic to the host. To identify potential anti-Pneumocystis agents, we synthesized bisbenzamidine derivatives in which the parent compound pentamidine was modified by a 1,4-piperazinediyl, alkanediamide, or 1,3-phenylenediamide moiety as the central linker. Several of the compounds were more active against P. carinii and less toxic than pentamidine in cytotoxicity assays. For this study, we evaluated nine bisbenzamidine derivatives representing a range of in vitro activities, from highly active to inactive, for the treatment of pneumocystosis in an immunosuppressed mouse model. Six of these in vitro-active compounds, 01, 02, 04, 06, 100, and 101, exhibited marked efficacies against infection at a dose of 10 mg/kg of body weight, and four compounds, 01, 04, 100, and 101, showed significant increases in survival versus that of untreated infected control mice. Compound 100 was highly efficacious against the infection at 20 mg/kg and 40 mg/kg, with > 1,000-fold reductions in burden, and resulted in improved survival curves versus those for pentamidine-treated mice (at the same doses). All six bisbenzamidine compounds that exhibited high in vitro activity significantly decreased the infection in vivo; two compounds, 12 and 102, with marked to moderate in vitro activities had slight or no activity in vivo, while compound 31 was inactive in vitro and was also inactive in vivo. Thus, the selection of highly active compounds from in vitro cytotoxicity assays was predictive of activity in the mouse model of Pneumocystis pneumonia. We conclude that a number of these bisbenzamidine compounds, especially compound 100, may show promise as new anti-Pneumocystis drugs.

Highly active anti-Pneumocystis carinii compounds in a library of novel piperazine-linked bisbenzamidines and related compounds

Trimethoprim-sulfamethoxazole and pentamidine isethionate have been used extensively for the prophylaxis and therapy of pneumonia caused by Pneumocystis jirovecii. Problems associated with toxicity and potential emerging resistance for both therapies necessitate the development of safe and effective analogs or new treatment strategies. In the present study, a library of 36 compounds was synthesized by using the pentamidine molecule as the parent compound modified by a 1,4-piperazinediyl moiety as the central linker to restrict conformation flexibility. The compounds were evaluated for anti-Pneumocystis carinii activity in a bioluminescent ATP-driven assay. Four of the compounds were highly active, with 50% inhibitory concentration (IC(50)) values of <0.01 microg/ml; four had very marked activity (IC(50) < 0.10 microg/ml); ten had marked activity (IC(50) < 1.0 microg/ml); nine had moderate activity (IC(50) < 10 microg/ml); one had slight activity (IC(50) = 34.1 microg/ml); and the remaining eight did not demonstrate activity in this assay system. The high level of activity was specifically associated with an alkyl chain length of five to six carbons attached to one of the nitrogens of the bisamidinium groups. None of the highly active compounds and only one of the very marked compounds exhibited any toxicity when evaluated in three mammalian cell lines. The strategy of substitution of 1,4-piperazine-linked bisbenzamidines produced compounds with the highest level of activity observed in the ATP assay and holds great promise for the development of efficacious anti-P. carinii therapy.

Altered Glucose Metabolism in HIV-infected Patients Treated With HAART

The introduction of protease inhibitors (PIs) has revolutionized the treatment of human immunodeficiency virus (HIV)– positive patients. The consequences of potential long-term metabolic complications have led to the use of PI-sparing regimens. As HIV treatment with PIs is associated with lipodystrophy (fat redistribution, hyperlipidemia, and glucose intolerance), it is essential to effectively manage these long-term toxicities. The impact of PI-induced glucose intolerance has resulted in studies investigating both pathogenesis andmanagement of this side effect. The action of PIs on the glucose transporter, GLUT4, may explain themechanismof action of PI use on glucose tolerance. Insulin-sensitizing agents, such as metformin and thiazolidinediones, may improve glucose intolerance, insulin resistance, and lipodystrophy caused by PI therapy.

The validity of the Medisafe self-monitoring blood glucose system

Self-monitoring blood glucose (SMBG) meters are widely used in the management of diabetes. The new SMBG meter Medisafe, which is based on the optoelectric colorimetry method, has been introduced. The objective of this study was to validate the Medisafe SMBG meters in comparison with the reference autoanalyzer (Hitachi 717) and to assess the repeatability of the instrument as well as variations of tip replacement. Samples of capillary and venous blood from 299 patients were tested. The correlation coefficients between the Medisafe-measured capillary and venous blood glucose levels and the reference autoanalyzer venous plasma glucose levels were 0.976 and 0.975, respectively. The range of differences from the reference value was examined; only 4% was in excess of +/- 20% of the reference laboratory value, and more than 40% of the values were within 5% of the reference laboratory value. Moreover, repeatability of the Medisafe capillary blood samples measured in three patients with three different blood glucose levels was determined. The coefficients of variation of blood glucose values are within 5%. In addition, the results of mean and SEM from each replication in three patients and glucose measurement from different lots of tips showed no significant difference (p > 0.05). It is concluded that the Medisafe SMBG meter has shown good results in terms of validity and repeatability. Furthermore, it provides safety from blood contamination, which is recommended in countries with a high prevalence of human immunodeficiency virus.

Autopsy findings in diabetic patients: a 27-yr clinicopathologic study with emphasi on opportunistic infections and cancers

Diabetes mellitus has become a growing epidemic in the Asia-Pacific region. The aims of this study were to determine at autopsy the prevalence and characteristics of pathologic lesions in patients with diabetes mellitus. The 13,215 autopsy reports in our institution were examined for the diagnosis of diabetes mellitus. In patients with diabetes mellitus, the demographic data and the different pathologic lesions noted were analyzed. Diabetes mellitus was found in 820 patients (426 men and 394 women), comprising 6.2% of all autopsies. The two most common types of disease were cardiovascular diseases and infections, found in 69 and 53% of diabetic patients, respectively. Bacterial infection, in particular tuberculosis, was the most common type of infection noted. Localized and disseminated fungal infections were also common. In addition, urinary tract diseases were noted in 48%, hepatobiliary tract lesions in 42%, central nervous system disorders in 25%, and tumors in 29% of the diabetic patients. Malignant tumors were more often seen than benign tumors (18 vs 11% of patients, respectively). Many of the tumors were adenocarcinomas, and the most common neoplastic lesions were carcinomas of the lung, pancreas, liver, large intestine, stomach, and esophagus. Diabetic complications and associated diseases are common problems in this population. Adequate health care resources are needed for their prevention and treatment.

Accuracy of glucose meter use in gestational diabetes

Glucose monitoring is essential for the successful management of gestational diabetes. The accuracy of glucose meters is typically determined over a much wider range of glucose values than that commonly encountered in gestational diabetes. The objective of our study was to look at the accuracy of self-monitoring glucose meters in a clinic setting over a range of glucose values seen in gestational diabetes. We retrospectively analyzed 107 case records of subjects with gestational diabetes, each of whom had three simultaneous laboratory and glucose meter glucose tests. The results were compared using the performance goals that (1) all of glucose meters should have readings within 10% of the reference value and (2) the error grid analysis in the standard format and a modified version suitable for gestational diabetes. We also examined the range of the differences from the reference value. Nearly half of the values (47%) were in excess of 10% of the reference range (either above or below). Close to 15% were in excess of 20% difference from the reference range. Standard error grid analysis showed that 96% of the values fell within sections A of the error grid which are considered acceptable, and 100% fell within sections A and B, differences which are generally considered to have no major impact on care. The modified version of the error grid analysis demonstrated that 39% of the values were outside the acceptable range. Within subjects, a substantial number (26%) had a range of differences that exceeded 20% difference between each other. Although the meters give reasonable results that might be acceptable for general diabetes care, the results provide some cause for concern in the management of gestational diabetes. Given the need for precision in the setting of pregnancy particularly in making the decision of whether to start or withhold insulin therapy, caregivers need to be cognizant of these inaccuracies.

Disorders of glucose metabolism in patients infected with human immunodeficiency virus

New-onset diabetes mellitus, clinically similar to type 2 diabetes, will affect a small proportion (1%-6%) of patients infected with human immunodeficiency virus (HIV) who are treated with HIV-1 protease inhibitors (PIs). However, insulin resistance and impaired glucose tolerance will develop during PI treatment in a considerable proportion of patients. Dyslipidemia, abdominal obesity, and loss of peripheral fat frequently coexist with insulin resistance, but it is not clear whether all of these result from a common pathogenic mechanism. Recent data suggest that insulin resistance may also be associated with HIV infection in patients not receiving PI therapy. The long-term consequences of insulin resistance in this population are not known. The effect of switching to other antiretroviral therapies has not been fully determined. Treatment of established diabetes mellitus should generally follow existing guidelines. There is no clinically useful screening test that will determine the existence and degree of insulin resistance in individual patients. It is therefore reasonable to recommend general measures to increase insulin sensitivity in all patients infected with HIV, such as weight reduction for obese persons and regular aerobic exercise.

Assessment of five portable blood glucose meters for use in cats

OBJECTIVE

To evaluate the clinical and analytic accuracy of 5 portable blood glucose meters (PBGM) in cats, with emphasis on the detection of potential sources of error.

ANIMALS

200 cats.

PROCEDURE

Venous blood glucose readings from 5 PBGM were compared with the results of a hexokinase reference method. Agreement among methods was determined by error grid analysis and statistical methods.

RESULTS

A total of 2,975 PBGM readings and 513 reference values were analyzed. The accuracy of the PBGM varied in different glycemic ranges. The largest differences between PBGM readings and reference values were in the high glycemic range; 4 PBGM underestimated and 1 PBGM overestimated the reference values in most instances. In the low and reference glycemic ranges, the absolute differences between PBGM readings and reference values were small. Despite the analytic differences in accuracy, 4 PBGM had 100% and 1 PBGM had 98.7% of readings in the clinically acceptable values of the error grid analysis. Within- and between-day precisions were good for all PBGM. Significant differences were not detected between readings of EDTA and lithium-heparinized blood and fresh blood without anticoagulant. Compared with these blood types, 1 PBGM had significantly different readings with fluoride anticoagulated blood. In blood samples with a low Hct, all PBGM overestimated glucose concentrations. Sample volumes < 3 microl resulted in inaccurate measurements in 3 PBGM.

CONCLUSIONS AND CLINICAL RELEVANCE

Performance varied among the 5 PBGM analyzed; however, all PBGM were deemed acceptable for clinical use in cats.

Immunoassays for pentamidine and related compounds: development of a facile inhibitory ELISA suitable for clinical use

Aromatic dicationic drugs have a broad spectrum of activity against protozoal and fungal pathogens including Pneumocystis carinii, Leishmania mexicana amazonensis, Cryptosporidium parvum and Cryptococcus neoformans. Pentamidine serves as the exemplar for an extensive collection of newly synthesized related compounds, which have reduced toxicity and a wider range of target organisms. Assays of pentamidine and related compounds have depended on HPLC-tandem mass spectrometry (HPLC-TMS) for the quantitation and identification of drug and metabolites. Immunoassays for pentamidine would have many advantages over the HPLC methods including relative simplicity of assay format and required equipment, convenience in sample preparation and reduction in time and cost of assays. In this report we describe a simple ELISA based immunoassay for pentamidine and pentamidine-like drugs with requisite sensitivity and specificity for use as a clinical assay (EC50 value of about 50 nanomolar). Immunogen was synthesized by coupling the hapten aminopentamidine to ovalbumin (chemically modified to provide an optimal number of -SH groups) using sulfo-MBS. Maleic-anhydride activated ELISA plates were covalently sensitized using the aminopentamidine hapten and used in an inhibitory ELISA assay format whereby the ability of analyte to suppress antibody binding to sensitized plate was measured. The assay detects primarily the phenolic amidine of pentamidine when in a para position and hence can also detect structurally related derivatives of pentamidine of potential interest as new therapeutic agents.

Drug-induced hypoglycemia

Therapeutically administered antidiabetic drugs, notably insulin and the sulfonylureas, are undoubtedly the most common cause of hypoglycemia encountered in clinical practice. Nevertheless, an impressive list of other drugs can produce hypoglycemia unpredictably in seemingly healthy individuals in whom it may masquerade as spontaneous hypoglycemia. Unless the true cause is identified when the patient is first seen, fruitless and expensive overinvestigation may ensue. The most important drugs are discussed herein and brief mention made of those for which coincidence has not been eliminated.

1,5-Bis(4-amidinophenoxy)pentane (pentamidine) is a potent inhibitor of [3H]idazoxan binding to imidazoline I2 binding sites

The aromatic diamidine 1,5-bis(4-amidinophenoxy)pentane (pentamidine) is used for treatment and prophylaxis of Pneumocystis carinii pneumonia in patients with Acquired Immune Deficiency Syndrome. Clinical use of pentamidine has been restricted by significant toxicity, that includes hypotension, and hypoglycemia. Although clinical toxicity is well described, the mechanisms are still poorly understood. Competitive binding analyses using [3H]idazoxan as the radioligand, and cirazoline to define non-specific binding, demonstrate that pentamidine binds to an imidazoline I2 binding site on rat liver membranes with a Ki of 1.4+/-0.22 nM. The Ki indicates that pentamidine inhibits radioligand binding at imidazoline I2 sites with an affinity approximating the most potent known ligands and may be related to pentamidine toxicity. Moreover, pentamidine analogs inhibit radioligand binding with a range of affinities that vary according to their structure. Two candidate drugs, Compounds 5 and 6, are more active than pentamidine in the corticosteroid-suppressed rat model of P. carinii pneumonia, yet have different affinities for the imidazoline I2 site (Ki 5 = 50.1+/-1.06 nM and Ki 6 = approximately 3500 nM). Affinity for this site does not correlate with antimicrobial activity (r = 0.60; p = 0.09) or the calculated log of the octanol:water partition coefficient (ClogP) (r = -0.38; p = 0.22).

Severe hyperglycemia in an HIV clinic: preexisting versus drug-associated diabetes mellitus

We determined the frequency and clinical nature of severe hyperglycemia in a university clinic for HIV-1-infected patients. The medical records of 1392 adult HIV-infected patients were reviewed for cases of severe hyperglycemia, defined as two or more serum glucose values >250 mg/dl or diabetes treatment during clinic care. Demographic information, family histories of diabetes mellitus, body weights, CD4+ lymphocyte counts, and use of corticosteroids, megestrol acetate, pentamidine, or didanosine were recorded for subjects meeting the case definition. Comparisons were made between preexisting diabetic (group 1) and incident hyperglycemic cases (group 2). Less than 2% of the total clinic population experienced severe hyperglycemia: 12 in group 1 and 13 in group 2. Group 2 had lower body weights (mean, 70.6 kg versus 90.0 kg; p < 0.05) and more advanced HIV disease (mean CD4 count, 79/mm3 versus 550/mm3; p < 0.05) than group 1. Group 2 cases had evidence of drug-associated hyperglycemia; four cases demonstrated hyperglycemia coinciding with large fluctuations in weight during megestrol therapy. Among megestrol recipients, cases did not differ from noncases in demographics, weight, or CD4 count. Severe hyperglycemia is uncommon in adult HIV-infected patients. Approximately one half of these patients have preexisting diabetic conditions; many of the remainder may have drug-induced hyperglycemia, especially as a result of corticosteroids or megestrol acetate.

The accuracy of home glucose meters for the glucose range anticipated in pregnancy

Home glucose meters are used almost universally for the management of pregnant women with diabetes. However, the degree of accuracy of meters in general and particularly for the lower glucose range, is questionable. Six of the most commonly used meters in Australia were evaluated for analytical accuracy for glucose levels < 8.0 mmol/L--a level below which many important clinical management decisions are made. Two meters, Elite and Precision QID, cannot be recommended. The other 4 meters, Glucometer 3, Reflolux S, Alpha and Advantage produced results with a higher degree of analytical accuracy. Of the meters tested, the Accutrend Alpha had the highest proportion of results within 5% and 10% of a laboratory reference method, the lowest bias with the Altman Bland method of comparison, and is recommended for use in pregnancy. No meter approached the analytical accuracy goal recommended by the American Diabetes Association. Manufacturers should be encouraged to develop or adapt systems for use in pregnancy.

Application of computers in diabetes care--a review. II. Computers for decision support and education

This paper concludes a review of the contribution of information technology to diabetes care. The role of decision support tools for planning insulin therapy using various clinical algorithms, knowledge-based approaches and interactive simulations is discussed, and certain telemedicine approaches to therapy are considered. The validation and clinical evaluation of these tools is reviewed, as is the likely impact of the routine clinical application of implantable/non-invasive blood glucose monitoring devices. Finally, the application of computers as teaching tools is considered, and ways in which such educational approaches might be applied for disseminating the benefits of the Diabetes Control and Complications Trial more widely are discussed.