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Johnston A.,Clinical Pharmacology | Holt D.W.,St Georges, University of London
British Journal of Clinical Pharmacology

Poor-quality medicines present a serious public health problem, particularly in emerging economies and developing countries, and may have a significant impact on the national clinical and economic burden. Attention has largely focused on the increasing availability of deliberately falsified drugs, but substandard medicines are also reaching patients because of poor manufacturing and quality-control practices in the production of genuine drugs (either branded or generic). Substandard medicines are widespread and represent a threat to health because they can inadvertently lead to healthcare failures, such as antibiotic resistance and the spread of disease within a community, as well as death or additional illness in individuals. This article reviews the different aspects of substandard drug formulation that can occur (for example, pharmacological variability between drug batches or between generic and originator drugs, incorrect drug quantity and presence of impurities). The possible means of addressing substandard manufacturing practices are also discussed. A concerted effort is required on the part of governments, drug manufacturers, charities and healthcare providers to ensure that only drugs of acceptable quality reach the patient. © 2013 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society. Source

Carmichael S.J.,University of Queensland | Day R.O.,Clinical Pharmacology | Day R.O.,University of New South Wales | Tett S.E.,University of Queensland
Internal Medicine Journal

Background/Aims: To investigate the pharmacokinetics of hydroxychloroquine (HCQ) and relationships of HCQ concentration with disease activity variables (concentration-effect relationships) in patients with systemic lupus erythematosus (SLE). Methods: HCQ concentration and disease activity were measured at a single time point in 60 patients with SLE receiving HCQ for at least 6 months. Some retrospective objective data on disease activity prior to HCQ commencement were available. Correlations were sought between HCQ blood concentrations and disease variables (Systemic Lupus Activity Measure (SLAM) scores, joint scores, morning stiffness, pain, well-being, general improvement, other medication use (including corticosteroids), and physician and patient assessments). Blood HCQ concentrations were also dichotomised into 'more' and 'less/no' disease activity, and mean blood concentrations in the two groups for each disease activity measure were compared. Results: The pharmacokinetics (dose-concentration relationships) of HCQ were highly variable in people with SLE. Apparent total clearance of HCQ from blood was 316 (± 319) mL/min (mean (± standard deviation). There was no correlation between SLAM score, patient global assessment or physician global assessment, and blood HCQ concentrations (r2 = 0.2, 0.04 and 0.13, respectively; P > 0.05). However, during HCQ therapy, 64% (14 of 22 patients) had a reduction in prednisolone dose of 50% or more compared with pre-HCQ therapy. Conclusions: No significant concentration-effect relationship for HCQ in the treatment of SLE was observed perhaps because consistently high enough blood HCQ concentrations were not achieved. Pharmacokinetic variability led to a wide range of blood HCQ concentrations. A concentration-targeting study for HCQ in SLE would be timely. © 2013 Royal Australasian College of Physicians. Source

Kuthiala G.,SPS Apollo Hospitals | Chaudhary G.,Clinical Pharmacology
Indian Journal of Anaesthesia

Ropivacaine is a long-acting amide local anaesthetic agent and first produced as a pure enantiomer. It produces effects similar to other local anaesthetics via reversible inhibition of sodium ion influx in nerve fibres. Ropivacaine is less lipophilic than bupivacaine and is less likely to penetrate large myelinated motor fibres, resulting in a relatively reduced motor blockade. Thus, ropivacaine has a greater degree of motor sensory differentiation, which could be useful when motor blockade is undesirable. The reduced lipophilicity is also associated with decreased potential for central nervous system toxicity and cardiotoxicity. The drug displays linear and dose proportional pharmacokinetics (up to 80 mg administered intravenously). It is metabolised extensively in the liver and excreted in urine. The present article details the clinical applications of ropivacaine and its current place as a local anaesthetic in the group. Source

Nizar H.,Clinical Pharmacology | Dargan P.I.,Clinical Toxicology | Dargan P.I.,Kings College London | Wood D.M.,Clinical Toxicology | Wood D.M.,Kings College London
Journal of Medical Toxicology

4,4′-Dimethylaminorex is a stimulant novel psychoactive substance (NPS) first detected in Europe in November 2012. It is a derivative of 4-methylaminorex, a substance controlled under Schedule 1 of the 1971 United Nations Convention on Psychotropic Substances. There is currently no information on the availability or cost of these substances from Internet suppliers. An Internet snapshot study was undertaken in English using established European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) methodology to determine the availability of 4-methylaminorex and 4,4′-dimethylaminorex in April 2014. Twenty Internet sites selling 4-methylaminorex were identified, 18 selling in US dollars and two in GB Pound Sterling. Fourteen (70 %) Internet sites had a minimum purchase amount of ≥10 g (compared to user doses of 10-25 mg). For the 18 suppliers selling in US$, 9 quoted a fixed price per gram irrespective of the amount ordered and 11 had a reducing price per gram with increasing purchase quantity (US$30.8 ± 34.2/g for 1 g purchase to US$15.2 ± 20.3/g for 1 kg purchase). Only one Internet site selling 4,4′-dimethylaminorex was identified, selling in Euros. The minimum purchase quantity was 500 mg. The price per gram reduced from €36.08/g for a 500 mg purchase to €2.20/g for a 100 g purchase. This Internet snapshot demonstrated that there was a greater availability from Internet suppliers of products advertised as 4-methylaminorex than 4,4′-dimethylaminorex, despite the 4-methylaminorex being an internationally controlled substance. Whilst this may reflect misunderstanding by suppliers, it has the potential to put those purchasing at risk of contravening border control and/or local law enforcement legislation. The use of methodology such as Internet snapshot surveys is of increasing interest to clinical/medical toxicologists in their understanding of the supply, availability and cost of novel psychoactive substances. © 2014 American College of Medical Toxicology. Source

Stanners M.N.,University of Adelaide | Barton C.A.,Flinders University | Shakib S.,Clinical Pharmacology | Winefield H.R.,University of Adelaide
Aging and Mental Health

Primary care providers often struggle to identify depression, with patients with multiple chronic conditions presenting additional unique challenges. Whilst the diagnosis and treatment of depression has been explored in a range of contexts in the literature, there is a paucity of information on the impact of multimorbidity on general practitioners (GPs) attempting to diagnose and manage depression in primary care. Eight GPs with multiple referrals to a multidisciplinary clinic engaged in a semi-structured interview to discuss the impact of multimorbidity on the diagnosis and detection of depression. Interviews were transcribed and thematic analysis was used to identify key themes. Grounded theory was generated from data relating to the role of multimorbidity. Participants described multimorbidity as obscuring symptom causation, but also creating time to investigate causation and negotiate the depression diagnosis with the patient, and generating relationship through frequent presentations. Knowledge of the patient impacted on intervention recommendations, and trust facilitated patient receptivity. Treatment was affected by a range of variables, and included medical and social interventions. GP process for multimorbid patients is similar to that of patients with chronic illness. Further research is needed to know whether different processes or diagnostic categories are warranted where multiple chronic illnesses are present. Also, GPs recommend social interventions where medical interventions are perceived as inappropriate. Research into the efficacy of social interventions in multimorbid patients is needed. © 2012 Copyright Taylor and Francis Group, LLC. Source

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