Pharmacotherapy
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Idiopathic thrombocytopenic purpura (ITP) is a platelet disorder that affects approximately 1 in 10,000 people. In adults, the rate of spontaneous remission is only 5%, and generally, it is a chronic disease persisting for more than 6 months. Chronic refractory ITP may be defined as the failure of any modality to keep the platelet count above 20 x 10(3)/mm(3) for an appreciable time without unacceptable toxicity. ⋯ When deciding which of these agents to prescribe, considerations include oral versus injectable dosage form, adverse-event profiles, and patient adherence with both taking the drug and keeping clinic appointments for monitoring of platelet counts. Several studies are under way to evaluate these drugs in chronic refractory ITP as well as other disease states. Long-term data will also be needed to assess the safety and efficacy of these agents.
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Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery that increases patient morbidity, length of stay, and hospital costs. A substantial body of evidence exists evaluating various pharmacologic and nonpharmacologic methods to decrease the occurrence of POAF in an effort to decrease its burden on the health care system. Evidence-based guidelines support the use of beta-blockers as standard prophylaxis of POAF in patients undergoing cardiac surgery. ⋯ Currently, available evidence does not support the use of propafenone, procainamide, digoxin, thiazolidinediones, triiodothyronine, or calcium channel blockers in the prevention of POAF. Preliminary evidence suggests that dofetilide, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), nonsteroidal antiinflammatory drugs, corticosteroids, omega-3 fatty acids, ascorbic acid, N-acetylcysteine, and sodium nitroprusside may be effective in preventing POAF. Additional large-scale, adequately powered clinical studies are needed to determine the benefit of these agents before they can be considered for routine use.
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Septic shock is a major cause of morbidity and mortality in the intensive care unit, and effective therapies are limited. Methylene blue is a selective inhibitor of guanylate cyclase, a second messenger involved in nitric oxide-mediated vasodilation. The use of methylene blue in the treatment of septic shock has been repeatedly evaluated over the past 20 years, but data remain scarce. ⋯ Observational studies with methylene blue have demonstrated beneficial effects on hemodynamic parameters and oxygen delivery, but use of methylene blue may be limited by adverse pulmonary effects. Methylene blue administration is associated with increases in mean arterial pressure while reducing catecholamine requirements in patients experiencing septic shock; however, its effects on morbidity and mortality remain unknown. Well-designed, prospective evaluations are needed to define the role of methylene blue as treatment of septic shock.