Germain M.,Medical Affairs
Transfusion | Year: 2016
BACKGROUND In most industrialized countries, men who had sex with men (MSM) are permanently deferred from blood donation. Some countries have adopted a temporary deferral after the MSM behavior, thus avoiding donations made during the window period of human immunodeficiency virus (HIV) infection. However, one concern with this approach is the possible increase in the number of HIV-positive donations obtained from unknowingly infected, abstinent MSM; such donations might inadvertently be made available for transfusion, a risk that was previously estimated through mathematical modeling. STUDY DESIGN AND METHODS Model predictions were compared to the actual donor rate of HIV in three countries that went from a permanent to a temporary deferral: Australia, the United Kingdom, and Canada. RESULTS Depending on the model, a temporary deferral should have increased the rate of HIV in the male donor pool by 73% to more than 3400%. In reality, the very low baseline rate of HIV before the change in these three countries (22 cases/year) remained unchanged 2 years after the revised policy (16 cases/year). CONCLUSION These observations strongly suggest that a temporary deferral for MSM incurs zero risk to recipients, at least in jurisdictions where HIV epidemiology is comparable to that of countries where the change happened. © 2016 AABB.
Ermer J.C.,Shire Inc |
Adeyi B.A.,Shire Inc |
Pucci M.L.,Medical Affairs
CNS Drugs | Year: 2010
Methylphenidate- and amfetamine-based stimulants are first-line pharmacotherapies for attention-deficit hyperactivity disorder, a common neurobehavioural disorder in children and adults. A number of long-acting stimulant formulations have been developed with the aim of providing once-daily dosing, employing various means to extend duration of action, including a transdermal delivery system, an osmotic-release oral system, capsules with a mixture of immediate- and delayed-release beads, and prodrug technology.Coefficients of variance of pharmacokinetic measures can estimate the levels of pharmacokinetic variability based on the measurable variance between different individuals receiving the same dose of stimulant (interindividual variability) and within the same individual over multiple administrations (intraindividual variability). Differences in formulation clearly impact pharmacokinetic profiles. Many medications exhibit wide interindividual variability in clinical response. Stimulants with low levels of inter- and intraindividual variability may be better suited to provide consistent levels of medication to patients. The pharmacokinetic profile of stimulants using pH-dependent bead technology can vary depending on food consumption or concomitant administration of medications that alter gastric pH. While delivery of methylphenidate with the transdermal delivery system would be unaffected by gastrointestinal factors, intersubject variability is nonetheless substantial. Unlike the beaded formulations and, to some extent (when considering total exposure) the osmotic-release formulation, systemic exposure to amfetamine with the prodrug stimulant lisdexamfetamine dimesylate appears largely unaffected by such factors, likely owing to its dependence on systemic enzymatic cleavage of the precursor molecule, which occurs primarily in the blood involving red blood cells. The high capacity but as yet unidentified enzymatic system for conversion of lisdexamfetamine dimesylate may contribute to its consistent pharmacokinetic profile.The reasons underlying observed differential responses to stimulants are likely to be multifactorial, including pharmacodynamic factors. While the use of stimulants with low inter- and intrapatient pharmacokinetic variability does not obviate the need to titrate stimulant doses, stimulants with low intraindividual variation in pharmacokinetic parameters may reduce the likelihood of patients falling into subtherapeutic drug concentrations or reaching drug concentrations at which the risk of adverse events increases. As such, clinicians are urged both to adjust stimulant doses based on therapeutic response and the risk for adverse events and to monitor patients for potential causes of pharmacokinetic variability. © 2010 Adis Data Information BV. All rights reserved.
Bailey C.J.,Aston University |
Kodack M.,Medical Affairs
International Journal of Clinical Practice | Year: 2011
Type 2 diabetes is a complex, progressive endocrine and metabolical disease that typically requires substantial lifestyle changes and multiple medications to lower blood glucose, reduce cardiovascular risk and address comorbidities. Despite an extensive range of available and effective treatments, < 50% of patients achieve a glycaemical target of HbA 1c < 7.0% and about two-thirds die of premature cardiovascular disease. Adherence to prescribed therapies is an important factor in the management of type 2 diabetes that is often overlooked. Inadequate adherence to oral antidiabetes agents, defined as collecting < 80% of prescribed medication, is variously estimated to apply to between 36% and 93% of patients. All studies affirm that a significant proportion of type 2 diabetes patients exhibit poor adherence that will contribute to less than desired control. Identified factors that impede adherence include complex dosing regimens, clinical inertia, safety concerns, socioeconomic issues, ethnicity, patient education and beliefs, social support and polypharmacy. This review explores these factors and potential strategies to improve adherence in patients with type 2 diabetes. © 2011 Blackwell Publishing Ltd.
Bergman G.E.,Medical Affairs
Thrombosis Research | Year: 2011
The availability of plasma-derived and recombinant coagulation factors has transformed the management of patients with bleeding disorders, such as hemophilia and von Willebrand disease (VWD). However, several important clinical challenges remain that have become the focus of current research in coagulation therapy. Two prospective, non-interventional studies (HyQoL-Europe and HyQoL-Canada) are evaluating the impact of major transitional life events, such as changes in social, work and living situations, on the quality of life of adolescents and young adults with hemophilia A who are treated with the recombinant factor VIII (rFVIII) concentrate Helixate®. A better understanding of the impact of these transitional life events on quality of life may help to develop improved interventions and counseling techniques that minimize the negative effects of these events on patients with bleeding disorders. A new clinical development program has been launched to evaluate the safety and efficacy of the low-volume, highly active, plasma-derived von Willebrand factor (VWF)/FVIII concentrate Biostate®. The program, known as SWIFT (Studies with von Willebrand factor/factor VIII) includes four clinical trials involving adult and pediatric patients with hemophilia A or VWD. Lastly, fusion of human recombinant albumin to recombinant coagulation factor IX (rFIX) has created a new fusion protein (rIX-FP) that retains the biological activity of rFIX and has a more favorable pharmacokinetic profile due to the longer half-life. The use of this novel fusion protein may offer several advantages to patients with hemophilia B: less frequent administration, prolonged protection from bleeding and improved compliance - increasing the likelihood of a positive clinical outcome. These examples of current research endeavors are intended to enhance the treatment experience as well as provide new and improved therapies for patients with bleeding disorders. © 2010 Elsevier Ltd.
Hakansson M.A.,Medical Affairs
Spinal Cord | Year: 2014
Study design: This is a narrative review summarizing prevalence and background of reusing catheters for intermittent catheterization. It also compares complications related to reuse versus single use.Objectives and setting: The objective of the review is to highlight the on-going debate regarding whether reuse of catheters is as safe as single-use technique and investigate why reuse is common in some countries (for example, Australia, Canada and the United States).Methods: The review is the result of systematic searches in several databases (for example, MEDLINE, EMBASE and CINAHL) using predefined key words and search strategy.Results: The literature does not explicitly recommend reuse but instead proposes patient-oriented choice. Even so, the prevalence of reuse is ∼50% in some regions. Both off-label reuse and reuse of catheters intended for multiple use occur. The former is not legally supported. There seems to be no consensus on how many times a catheter can be reused or how to clean it. Poor compliance and efficacy of cleaning techniques have been reported, increasing the risk for introducing bacterial contamination. The literature supports the use of single-use hydrophilic catheters to reduce the risk of urethral trauma and urinary tract infection with a reported incidence of the latter between 40 and 60%, as compared with 70-80% for reuse catheters. Further clinical studies are however needed to verify/reject a difference.Conclusion: Complications associated with reuse need to be further investigated. Although awaiting evidence, it is recommended to use a confirmed safe, patient-preferred, noninfecting and nontraumatic technique for intermittent catheterization. © 2014 International Spinal Cord Society.