Internal Medicine Essentials
American College of Physicians

About IM Essentials


Philip A. Masters, MD, FACP
Senior Physician Educator
American College of Physicians
Philadelphia, Pennsylvania

Associate Editors

Jonathan S. Appelbaum, MD, FACP
Associate Professor, Clinical Sciences Department
Director, Internal Medicine Education
Florida State University College of Medicine
Tallahassee, Florida
Thomas M. De Fer, MD, FACP
Professor of Medicine
Director, Internal Medicine Clerkship
Washington University School of Medicine
Saint Louis, Missouri
Susan T. Hingle, MD, FACP
Associate Professor of Medicine
Internal Medicine Clerkship Director
Southern Illinois University School of Medicine
Springfield, Illinois
Robert Trowbridge, MD, FACP
Assistant Professor of Medicine
Tufts University School of Medicine
Director of Undergraduate Medical Education
Department of Medicine
Maine Medical Center
Portland, Maine
T. Robert Vu, MD, FACP
Associate Professor of Clinical Medicine
Director, Internal Medicine Clerkship
Indiana University School of Medicine
Indianapolis, Indiana

ACP Editorial Staff

Edward B. Warren
Project Manager
Lisa Levine
Editorial Production
Rosemarie Houton
Editorial Production

ACP Principal Staff

Patrick C. Alguire, MD, FACP
Senior Vice President, Medical Education
Sean McKinney
Vice President, Medical Education

CDIM Principle Staff

Sheila T. Costa
AAIM Director of Development and Communications
Alliance for Academic Internal Medicine


The American College of Physicians (ACP) gratefully acknowledges the special contributions to the development and production of the 1st edition of IM Essentials made by the following people:

Graphic Services: Michael Ripca (Technical Administrator/Graphic Design), Barry Moshinski (Art Director, Graphics Services), Thomas Malone (Graphics Production Supervisor)

Production/Systems: Dan Hoffmann (Director, Web Services & Systems Development), Scott Hurd (Manager, Content Systems), Neil Kohl (Senior Architect), Chris Patterson (Senior Architect) and Robert Guthy (Systems Analyst/Developer).

IM Essentials Online: Under the direction of Steven Spadt, Vice President, ACP Digital Products & Services, the online version of IM Essentials was developed within the ACP’s Digital Product Development department, led by Brian Sweigard (Director). Other members of the team included Dan Barron (Senior Systems Analyst/Developer), Chris Forrest (Senior Software Developer/Design Lead), Kara Kronenwetter (Senior Web Developer), Brad Lord (Senior Web Application Developer), John McKnight (Senior Web Developer), and Nate Pershall (Senior Web Developer).

The College also wishes to acknowledge that many other persons, too numerous to mention, have contributed to the production of this program. Without their dedicated efforts, this program would not have been possible.

Disclosure Policy

It is the policy of the American College of Physicians (ACP) to ensure balance, independence, objectivity, and scientific rigor in all its educational activities. To this end, and consistent with the policies of the ACP and the Accreditation Council for Continuing Medical Education (ACCME), contributors to all ACP continuing medical education activities are required to disclose all relationships with any entity producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients. Contributors are required to use generic names in the discussion of therapeutic options and are required to identify any unapproved, off-label, or investigative use of commercial products or devices. Where a trade name is used, all available trade names for the same product type are also included. If trade-name products manufactured by companies with whom contributors have relationships are discussed, contributors are asked to provide evidence-based citations in support of the discussion. If necessary, adjustments to topics or contributors' roles in content development are made to balance the discussion. The editors of IM Essentials have ensured that content is based on best evidence and updated clinical care guidelines, when such evidence and guidelines were available. Contributors' disclosure information is reviewed by the editors and every effort was made to resolve any conflicts presented. Further, all readers of this text are asked to evaluate the content for evidence of commercial bias so that future decisions about content and contributors can be made in light of this information.

Educational Disclaimer

The editors and publisher of IM Essentials recognize that the development of new material offers many opportunities for error. Despite our best efforts, some errors may persist in print. Drug dosage schedules are, we believe, accurate and in accordance with current standards. Readers are advised, however, to ensure that the recommended dosages in IM Essentials concur with the information provided in the product information material. This is especially important in cases of new, infrequently used, or highly toxic drugs. Application of the information in IM Essentials remains the professional responsibility of the practitioner.

The primary purpose of IM Essentials is educational. Information presented, as well as publications, technologies, products, and/or services discussed, is intended to inform subscribers about the knowledge, techniques, and experiences of the contributors. A diversity of professional opinion exists, and the views of the contributors are their own and not those of the ACP. Inclusion of any material in the program does not constitute endorsement or recommendation by the ACP. The ACP does not warrant the safety, reliability, accuracy, completeness, or usefulness of and disclaims any and all liability for damages and claims that may result from the use of information, publications, technologies, products, and/or services discussed in this program.

Publisher’s Information

Copyright ©2015 by the American College of Physicians. All rights reserved.

This publication is protected by copyright. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic or mechanical, including photocopy, without the express consent of the ACP.

Unauthorized Use of This Book Is Against the Law

Unauthorized reproduction of this publication is unlawful. The ACP prohibits reproduction of this publication or any of its parts in any form either for individual use or for distribution.

The ACP will consider granting an individual permission to reproduce only limited portions of this publication for his or her own exclusive use. Send requests in writing to IM Essentials Permissions (Attn: Edward Warren), American College of Physicians, 190 N. Independence Mall West, Philadelphia, PA 19106-1572, or email your request to

ISBN: 978-1-938921-11-7

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