Allopurinol-Induced Recurrent DRESS Syndrome: Pathophysiology and Treatment

Hyperuricemia is present in approximately 5% of the population. The vast majority is asymptomatic and at no clinical risk. Allopurinol, an analog of hypoxanthine, has been widely used in clinical practice for more than 30 years for the treatment of hyperuricemia and gout. Two percent of patients develop a mild exanthema when on this drug, which usually resolves after withdrawal of the drug. A syndrome characterized by exfoliative dermatitis, hepatitis, interstitial nephritis, and eosinophilia, termed allopurinol hypersensitivity syndrome, has been described, and its etiology related to the accumulation of one of allopurinol's metabolites, oxypurinol, of which clearance is decreased in the setting of renal insufficiency and the use of thiazide diuretics. The term DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) Syndrome has been recently used to describe an entity presenting with similar features.     

Erratum to: Depression,anxiety, and quality of life in a large cohort of patients with rheumatic diseases: common,yet undertreated

Clinical Rheumatology -     

Bioactivation to an aldehyde metabolite—Possible role in the onset of toxicity induced by the anti-HIV drug abacavir

Aldehydes are highly reactive molecules, which can be generated during numerous physiological processes, including the biotransformation of drugs. Several non-P450 enzymes participate in their metabolism albeit alcohol dehydrogenase and aldehyde dehydrogenase are the ones most frequently involved in this process. Endogenous and exogenous aldehydes have been strongly implicated in multiple human pathologies. Their ability to react with biomacromolecules (e.g. proteins) yielding covalent adducts is suggested to be the common primary mechanism underlying the toxicity of these reactive species.     

The in vitro antioxidant properties of the Al-quercetin/βCD and Al-catechin/βCD inclusion compounds, rationalized in terms of their electrochemical behaviour

Inclusion compounds of Al-quercetin and Al-catechin complexes with β-cyclodextrin (βCD) were investigated. The complex and the inclusion compound of quercetin are more effective DPPH^? scavengers than the corresponding catechin compounds and the inclusion does not compromise their scavenging abilities, with only a slight decrease in the EC₅₀ values. This is in accordance with the electrochemical data, which revealed that the inclusion compounds have lower diffusion coefficients in aqueous solution than the non-included compounds. For the quercetin compounds, some spectroscopic properties were also addressed by means of UV–visible and NMR measurements in aqueous media.