Mayo Clinic proceedings
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Herpes zoster (HZ), commonly called shingles, is a distinctive syndrome caused by reactivation of varicella zoster virus (VZV). This reactivation occurs when immunity to VZV declines because of aging or immunosuppression. Herpes zoster can occur at any age but most commonly affects the elderly population. ⋯ The vaccine has been shown to reduce significantly the incidence of both HZ and PHN. The vaccine is well tolerated, with minor local injection site reactions being the most common adverse event. This review focuses on the clinical manifestations and treatment of HZ and PHN, as well as the appropriate use of the HZ vaccine.
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Milk-alkali syndrome (MAS) consists of hypercalcemia, various degrees of renal failure, and metabolic alkalosis due to ingestion of large amounts of calcium and absorbable alkali. This syndrome was first identified after medical treatment of peptic ulcer disease with milk and alkali was widely adopted at the beginning of the 20th century. With the introduction of histamine2 blockers and proton pump inhibitors, the occurrence of MAS became rare; however, a resurgence of MAS has been witnessed because of the wide availability and increasing use of calcium carbonate, mostly for osteoporosis prevention. ⋯ The exact pathomechanism of MAS remains uncertain, but a unique interplay between hypercalcemia and alkalosis in the kidneys seems to lead to a self-reinforcing cycle, resulting in the clinical picture of MAS. Treatment is supportive and involves hydration and withdrawal of the offending agents. Physicians and the public need to be aware of the potential adverse effects of ingesting excessive amounts of calcium carbonate.
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We identified English-language publications on hypersensitivity reactions to xenobiotics through the PubMed database, using the search terms drug and/or xenobiotic, hypersensitivity reaction, mechanism, and immune mediated. We analyzed articles pertaining to the mechanism and the role of T cells. Immune hypersensitivity reactions to drugs are mediated predominantly by IgE antibodies or T cells. ⋯ Thus, previous contact with the causative drug is not obligatory, and an immune mechanism should be considered as the cause of hypersensitivity, even in reactions that occur on primary exposure. Indeed, immune-mediated reactions to xenobiotics in patients without prior exposure to the agent have been described recently for radiocontrast media and neuromuscular blocking agents. Thus, the "allergenic" potential of a drug under development should be evaluated not only by screening its haptenlike characteristics but also by assessing its direct immunostimulatory potential.
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Mayo Clinic proceedings · Mar 2009
Meta AnalysisBenefits and risks of long-term amiodarone therapy for persistent atrial fibrillation: a meta-analysis.
To assess whether amiodarone, as part of a strategy to achieve sinus rhythm, is safe and effective compared with a placebo or rate control drug in patients with persistent atrial fibrillation (AF) of more than 30 days' duration. ⋯ Amiodarone, as part of a strategy to achieve and maintain sinus rhythm, appears to be safe and effective in patients with persistent AF. However, some patients may not tolerate the adverse effects of this agent.