Use of virostatics as a means of targeting human immunodeficiency virus infection.
ABSTRACT Current antiretroviral therapy has had a significant impact on HIV associated morbidity and mortality. Despite these positive outcomes current antiretroviral regimens have significant deficiencies which include multiple drug-drug interactions, high pill burdens, and considerable financial expense. Perhaps the greatest shortcoming is the apparent inability of current therapy to disrupt low level viremia in certain cellular reservoirs despite maximal virologic control as determined by polymerase chain reaction detection. These drug-resilient reservoirs preclude the ability to discontinue antiretrovirals while maintaining viral control. Additionally, they may be responsible at least in part for the evolution of drug resistant variants. Various researchers have proposed that certain immune modulating agents known as virostatics (i.e., hydroxyurea (HU), mycophenolate mofetil (MMF), and cyclosporine (CSA)) may have some efficacy in managing HIV disease and/or disrupting resilient reservoirs. These agents may act by reducing the pool of activated CD4+ cells which are susceptible to infection thereby inhibiting the characteristic immune over-activation seen in most HIV infected patients. Virostatics have primarily been studied in patients with advanced HIV disease and as components of trials involving structured treatment interruptions. These trials have demonstrated conflicting results with regard to viral load and CD4+ cell counts as well as potential adverse effects including immune suppression. Before widespread use of these agents can be recommended, larger, well controlled trials will need to be conducted to determine which virostatic agents are appropriate for use in HIV infected patients and the most efficacious time course within which to initiate these agents.
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ABSTRACT: Recent molecular studies of fetal hemoglobin (HbF) regulation have reinvigorated the field and shown promise for the development of clinical HbF inducers to be used in patients with β-thalassemia and sickle cell disease. However, while numerous promising inducers of HbF have been studied in the past in β-thalassemia patient populations, with limited success in some cases, no universally effective agents have been found. Here we examine the clinical studies of such inducers in an attempt to systematically review the field. We examine trials of agents including 5-azacytidine, hydroxyurea, short-chain fatty acids, and others in this review. This review highlights the heterogeneity of clinical studies done on these agents, including both the patient populations examined and the study end points. By examining the published studies of these agents, we hope to provide a resource that will be valuable for the design of future studies of HbF inducers in β-thalassemia patient populations.Blood 01/2013; · 9.78 Impact Factor
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ABSTRACT: Abstract Context: This work investigated the production of pure indinavir free base nanoparticles by a supercritical anti-solvent method to improve the drug dissolution in intestine-like medium. Objective: To increase the dissolution of the drug by means of a supercritical fluid processing method. Materials and methods: Acetone was used as solvent and supercritical CO2 as antisolvent. Products were characterized by dynamic light scattering (size, size distribution), scanning electron microscopy (morphology), differential scanning calorimetry (thermal behaviour) and X-rays diffraction (crystallinity). Results and discussion: Processed indinavir resulted in particles of significantly smaller size than the original drug. Particles showed at least one dimension at the nanometer scale with needle or rod-like morphology. Results of X-rays powder diffraction suggested the formation of a mixture of polymorphs. Differential scanning calorimetry analysis showed a main melting endotherm at 152 °C. Less prominent transitions due to the presence of small amounts of bound water (in the raw drug) or an unstable polymorph (in processed IDV) were also visible. Finally, drug particle size reduction significantly increased the dissolution rate with respect to the raw drug. Conversely, the slight increase of the intrinsic solubility of the nanoparticles was not significant. Conclusions: A supercritical anti-solvent method enabled the nanonization of indinavir free base in one single step with high yield. The processing led to faster dissolution that would improve the oral bioavailability of the drug.Drug Development and Industrial Pharmacy 09/2013; · 2.01 Impact Factor