Drug Induced Long QT Syndrome

Mutations in genes coding for cardiac potassium or sodium channels may cause the long QT syndrome (LQTS) (160), which in some patients may lead to drug-induced torsade de pointes or polymorphic ventricular tachycardia. These patients are usually asymptomatic until administration of the drug. Drugs implicated include the antimalarials—mefloquine and halofantrine, the antiarrhythmics—quinidine and disopyramide and amiodarone, the antihistamines—terfenadine and oxatomide, and the antibiotics clarithromycin, erythro-mycin, and sulfamethoxazole (161-163).

To date, only small numbers of patients have been studied, a major problem being the inconsistencies in the phenotypic classification of these patients and also the relative rarity of patients with torsades, when compared with the LQTS. Three mutations have been associated with the acquired LQTS in the potassium and sodium channels (161,164). However, in more than 85% of the patients with the acquired LQTS, no ion channel mutations have been identified so far. At present, therefore, genetic testing is not warranted; there are several ongoing large-scale studies both in the United Kingdom and United States, and their results are anxiously awaited.

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Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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