Mueller T, Gegenhuber A, Dieplinger B, Poelz W, Haltmayer M Capability of B-type natriuretic peptide (BNP) and amino-terminal proBNP as indicators of cardiac structural disease in asymptomatic patients with systemic arterial hypertension. Clin Chem. 2005 Dec;51(12):2245-51. Epub 2005 Oct 13.
Pacak K Preoperative management of the pheochromocytoma patient. J Clin Endocrinol Metab. 2007 Nov;92(11):4069-79. Review.
Plouin PF, Duclos JM, Soppelsa F, Boublil G, Chatellier G Factors associated with perioperative morbidity and mortality in patients with pheochromocytoma: analysis of 165 operations at a single center. J Clin Endocrinol Metab. 2001 Apr;86(4):1480-6.
Prys-Roberts C, Farndon JR Efficacy and safety of doxazosin for perioperative management of patients with pheochromocytoma. World J Surg. 2002 Aug;26(8):1037-42. Epub 2002 Jun 19.
Shen WT, Grogan R, Vriens M, Clark OH, Duh QY One hundred two patients with pheochromocytoma treated at a single institution since the introduction of laparoscopic adrenalectomy. Arch Surg. 2010 Sep;145(9):893-7. doi: 10.1001/archsurg.2010.159.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.