This page intentionally left blank. Pharmaceutical Calculations 13th Edition Pharmaceutical Calculations 13th Edition Howard C. Ansel, PhD Professor and Dean Emeritus College of Pharmacy University of Georgia Athens, Georgia AcquisitionsEditor:JohnGoucher ManagingEditor:MattHauber DirectorofNursingProduction:HelenEwan SeniorManagingEditor/Production:ErikaKors SeniorProductionEditor:MarianBellus Designer:HollyMcLaughlin ManufacturingCoordinator:MargieOrzech ProductionServices/Compositor:MarylandComposition/ASI 13thEdition Copyright(cid:2)2010WoltersKluwerHealth(cid:2)LippincottWilliams&Wilkins. Copyright(cid:2)2006,2001,1996,1991,1986byLippincottWilliams&Wilkins.Allrightsreserved.This bookisprotectedbycopyright.Nopartofthisbookmaybereproducedortransmittedinanyformorby anymeans,includingasphotocopiesorscanned-inorotherelectroniccopies,orutilizedbyanyinformation storageandretrievalsystemwithoutwrittenpermissionfromthecopyrightowner,exceptforbriefquotations embodiedincriticalarticlesandreviews.Materialsappearinginthisbookpreparedbyindividualsaspartof theirofficialdutiesasU.S.governmentemployeesarenotcoveredbytheabove-mentionedcopyright.To requestpermission,pleasecontactLippincottWilliams&Wilkinsat530WalnutStreet,PhiladelphiaPA 19106,[email protected](productsandservices). Thistextbookisintendedtoprovidetheunderpinningsofthemethodsusedinpharmaceuticalcalculations.The drugs,drugproducts,formulas,equations,uses,anddosesareincludedinthistextbookforthesolepurposeof providingexamplesinthetypesofcalculationsdescribed.Theinformationisnotintendedforuseinanypractice orclinicalapplication,norshoulditbeconsideredorconstruedasspecificforanyindividualpatientnorasa substituteforcurrentdrugpackageinserts.Theauthor,editors,andpublishermakenowarranty,expressor implied,withregardtothecontentsanduseofthispublicationandarenotresponsible,asamatterofproduct liability,negligence,orotherwise,foranyinjuryresultingfromanymaterialcontainedherein. 9 8 7 6 5 4 3 2 1 PrintedinChina FirstEdition,1945 LibraryofCongressCataloging-in-PublicationData Ansel,HowardC.,1933- Pharmaceuticalcalculations/HowardC.Ansel.—13thed. p.;cm. Includesbibliographicalreferencesandindex. ISBN978-1-58255-837-0 1.Pharmaceuticalarithmetic.I.Title. [DNLM:1.DrugDosageCalculations.2.DosageForms.3.DrugCompounding—methods.4. Prescriptions,Drug.5.WeightsandMeasures.QV748A618p2010] RS57.S862010 615′.1401513—dc22 2008045672 Carehasbeentakentoconfirmtheaccuracyoftheinformationpresentedandtodescribegenerally acceptedpractices.However,theauthors,editors,andpublisherarenotresponsibleforerrorsoromissionsor foranyconsequencesfromapplicationoftheinformationinthisbookandmakenowarranty,expressedor implied,withrespecttothecurrency,completeness,oraccuracyofthecontentsofthepublication. Applicationofthisinformationinaparticularsituationremainstheprofessionalresponsibilityofthe practitioner;theclinicaltreatmentsdescribedandrecommendedmaynotbeconsideredabsoluteand universalrecommendations. Theauthors,editors,andpublisherhaveexertedeveryefforttoensurethatdrugselectionanddosageset forthinthistextareinaccordancewiththecurrentrecommendationsandpracticeatthetimeofpublication. However,inviewofongoingresearch,changesingovernmentregulations,andtheconstantflowof informationrelatingtodrugtherapyanddrugreactions,thereaderisurgedtocheckthepackageinsertfor eachdrugforanychangeinindicationsanddosageandforaddedwarningsandprecautions.Thisis particularlyimportantwhentherecommendedagentisaneworfrequentlyemployeddrug. SomedrugsandmedicaldevicespresentedinthispublicationhaveFoodandDrugAdministration(FDA) clearanceforlimiteduseinrestrictedresearchsettings.Itistheresponsibilityofthehealthcareproviderto ascertaintheFDAstatusofeachdrugordeviceplannedforuseinhisorherclinicalpractice. LWW.COM Preface The thirteenth edition of Pharmaceutical Calculations represents a thorough update of this text- book,whichformorethansixdecadeshasmettheneedsofstudentsinthisimportantsubject area. One of the most apparent changes in this edition is the inclusion of learning objectives foreachchapter.Theintentisnotonlytodefinethepurposeanddirectthestudent’sfocusbut also to provide a basis for self-assessment following completion. Another important addition, appearing in the Introduction, presents a step-wise approach in solving calculations problems that should prove beneficial to students toward understanding and building confidence. Throughout its history, one of the distinguishing characteristics of this textbook has been theinclusion ofrelevant backgroundinformation toexplain thepharmaceutical and/orclinical purpose underpinning each type of calculation. This practice has been continued, with new content in such areas as e-prescriptions; medication orders in nursing homes; hospice-care; patientself-administrationofanalgesia;intravenousinfusionratecalculationsforthecriticalcare patient; patient conversions toalternative treatment plans; and other newand expanded areas. Another traditional feature of this textbook has been the substantial use of examples and practice problems. New problems have been added to reflect current drugs in use, including productsofbiotechnology.Forthefirsttime,severalproblemsarepresentedinmultiple-choice format to reflect the method of testing used in some academic programs and employed on standardized examinations. Several features that were introduced in the previous edition have been expanded, namely ‘‘Special Considerations,’’ used to point out the specific relevance of a type of calculation to a pharmaceuticsorclinicalapplication;‘‘CalculationsCapsules,’’whichpresentboxedsummaries of the principle calculations in a chapter; and, ‘‘Case in Point,’’ which present practical case studies requiring pharmaceutical calculations. Theauthoracknowledgesthedifficultyinarrangingthesequenceofchapterstosuittheorder used within each academic program. However, an attempt has been made to present a logical approach by placing the fundamentals of pharmaceutical calculations in the initial chapters, followedbychaptershavingaclinical-orpatient-carecontext,thenchaptersthataddressformu- lation and compounding calculations, and, finally, chapters described by some reviewers as meeting a ‘‘special interest.’’ The concluding section of review problems contains all of the types of problems presented inthechaptersandmaybeusedbothfor reviewandforcompetencyassessment.Anewsetof problems titled ‘‘Physicians’ Medication Orders’’ is introduced. Appendicesincludethecommonsystemsofmeasurementandintersystemconversion,select graphical methods, and a glossary of pharmaceutical dosage forms and associated routes of administration. v vi PREFACE New Companion Website PharmaceuticalCalculations,13thedition,includesadditionalresourcesforbothinstructorsand students, available on the book’s companion website at http://thePoint.lww.com/Ansel13e. Resources for Students and Instructors • InteractivemathcalculationsQuizBank,withmorethan400reviewproblemsanddetailed solutions. • Searchable Full Text Online Seetheinsidefrontcoverformoredetails,includingthepasscodeyouwillneedtogainaccess to the website. Acknowledgments The author gratefully acknowledges the professional contributions to his revision of pharmacy practitioner-educators Warren Beach, Ted Chaffin, Ken Duke, Elaine Lust, and Flynn Warren for lending their expertise and time. Gratitude also is extended to Loyd V. Allen Jr. and Shelly J. Prince for their continued courtesy in allowing liberal use of their work published in the InternationalJournalofPharmaceuticalCompoundingandinPharmaceuticalCalculations:ThePhar- macist’s Handbook. The authorthanks Barabara E. Lacher for theidea of incorporating learning objectives into the textbook and for other instructional materials. The assistance of James T. Stewart in providing access to current information from the United States Pharmacopeia 31 – National Formulary 26 is acknowledged with appreciation. SpecialtributeispaidtothememoryofMitchellJ.Stoklosawhoformorethan50yearsco- authored and sustained this textbook. He was a scholar, dedicated educator, valued colleague, delightful human being, and treasured friend. Gratitude is expressed to the reviewers for this revision whose experience was drawn upon during the planningprocess. The author appreciates their thoughtfulanalysis and constructive comments,whichhaveenhancedthiswork.Finally,appreciationisextendedtotheexceptional peopleatLippincottWilliams&Wilkinsfortheirmasterfuljobinthedesign,preparation,and production of this revision. Howard C. Ansel Athens, Georgia vii This page intentionally left blank.