Drug-drug interactions in cardiac and cardiothoracic intensive care units: an analysis of patients in an academic medical centre in the US.
BACKGROUND
Mortality and morbidity are increased in patients experiencing drug-drug interactions. Unfortunately, there is a paucity of literature describing clinically significant drug-drug interactions occurring in the intensive care unit (ICU). Knowing the clinically significant drug-drug interactions allows the opportunity for prevention through knowledge and computer-assisted programmes.


OBJECTIVE
To identify significant potential drug-drug interactions occurring in the cardiovascular ICU (CCU) and the cardiothoracic ICU (CTICU).


METHODS
Prospective, observational study conducted over a total of 8 weeks in February and March 2009.


METHODS
CCU and CTICU in a major academic medical centre (Presbyterian Hospital, University of Pittsburgh Medical Centre).


METHODS
All adult patients (>or=18 years of age) admitted during 1 month in each ICU.


METHODS
Micromedex and Lexi-Interact interaction databases were used to screen each patient's medication profile daily for the presence of potentially interacting drug pairs that would be considered a potential drug-drug interaction. A severity assessment using these databases was completed after a potential drug-drug interaction was identified.


METHODS
The frequency of significant drug-drug interactions, including those that were considered major or contraindicated, according to two commercially available interaction databases.


RESULTS
Evaluations of 400 patient medication profiles were conducted, resulting in 225 profiles possessing one or more potential drug-drug interactions. A total of 1150 potential interactions were identified, resulting in 287.5 potential interactions per 100 patient-days. Of the 1150 potential drug-drug interactions, 458 were unique interacting drug pairs; 5-9% of the potential interactions were considered major or contraindicated. Many of the significant and frequent potential interactions involved blood coagulation modifiers, potential interactions that could result in QTc prolongation, and cytochrome P450 inhibition. Micromedex and Lexi-Interact agreed on the severity ratings in 20.5% of the potential interactions.


CONCLUSIONS
Significant potential drug-drug interactions occur in the CCU and CTICU, highlighting the need for active surveillance to potentially prevent patient harm. Clinicians should also consider using two references for identifying interactions, due to the lack of congruence between sources.
Smithburger
Pamela L
PL
University of Pittsburgh School of Pharmacy, and Medical Intensive Care Unit, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA. smithburgerpl@upmc.edu
Kane-Gill
Sandra L
SL
Seybert
Amy L
AL
D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000368:Aged; D016208:Databases, Factual; D004347:Drug Interactions; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania; D004364:Pharmaceutical Preparations / Q000008:administration & dosage; D011446:Prospective Studies; D014481:United States
D004364:Pharmaceutical Preparations
Int J Med Inform. 2008 Jun;77(6):365-76
18023611
Intensive Care Med. 2009 Apr;35(4):603-12
19132344
J Am Med Inform Assoc. 2007 Jan-Feb;14(1):29-40
17068355
J Am Pharm Assoc (2003). 2004 Mar-Apr;44(2):136-41
15098847
Am J Nurs. 1974 Aug;74(8):1442-6
4495284
J Clin Pharm Ther. 2002 Oct;27(5):377-82
12383140
Eur J Clin Pharmacol. 2002 Oct;58(7):479-82
12389071
Arch Intern Med. 1988 Jul;148(7):1499-503
3382293
Drug Saf. 2005;28(12):1131-9
16329715
Int J Clin Pharmacol Ther. 2000 Nov;38(11):504-13
11097142
Anesthesiology. 2008 Apr;108(4):596-602
18362590
Crit Care Med. 2008 Jul;36(7):2041-7
18552694
Am J Health Syst Pharm. 2003 Jul 15;60(14 Suppl 3):S8-14
12908377
Qual Saf Health Care. 2010 Feb;19(1):55-9
20172884
Ann Pharmacother. 2006 Jul-Aug;40(7-8):1267-73
16849619
Ann Thorac Surg. 1995 Mar;59(3):664-7
7887708
Crit Care Med. 1997 Aug;25(8):1289-97
9267940
Clin Pharmacol Ther. 2001 Apr;69(4):260-5
11309555
J Am Med Inform Assoc. 2009 Jan-Feb;16(1):40-6
18952941
Med Care. 2002 Dec;40(12):1161-71
12458299
Hosp Pharm. 1993 Apr;28(4):296-7, 300-1, 305 passim
10136586
Arch Surg. 1998 Apr;133(4):442-7
9565127
Arch Intern Med. 2009 Sep 14;169(16):1465-73
19752403
J Am Pharm Assoc (Wash). 2002 May-Jun;42(3):439-48
12030631
Ann Pharmacother. 1996 Sep;30(9):926-34
8876849
Crit Care Nurs Q. 2000 Feb;22(4):1-13
11852961