Incidence and risk of potential adverse drug interactions in the emergency room.
OBJECTIVE
To determine the incidence and risk factors of potential adverse drug interactions occurring in patients in the emergency department.


METHODS
Survey of a random sample of medical records of elderly persons and other adults seeking care at an emergency department. The interactions were determined by a computer programme, reviewed using explicit criteria, and excluded if of uncertain or trivial clinical significance.


METHODS
University Hospital Medical Emergency Department.


METHODS
A total of 423 randomly selected adults seeking care at a university hospital emergency department. Attendances made by 195 persons over age 60 and 228 younger adults were evaluated. All subjects were treated on an outpatient basis.


METHODS
Seventy percent of attendances led to the prescription of an added medication. In 5.4% of the attendances in which at least one medication was added, the new medication introduced a potential adverse interaction. The number of medications used at attendance was the best predictor of whether a potential interaction would occur. Additional medications prescribed in the emergency department that accounted for most of the added interactions were theophylline, macrolid antibiotics, digitalis glycosides, nonsteroidal anti-inflammatory agents, angiotensin converting-enzyme inhibitors and calcium antagonists.


CONCLUSIONS
Potential adverse drug interactions were more common in elderly patients because of the higher number of concurrent medications rather than age-based factors. Safeguards need to be introduced to prevent patients from receiving medications in the emergency departments that have the potential to cause adverse interactions.
Heininger-Rothbucher
D
D
Division of General Internal Medicine, Department of Internal Medicine, Faculty of Medicine, University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria.
Bischinger
S
S
Ulmer
H
H
Pechlaner
C
C
Speer
G
G
Wiedermann
C J
CJ
D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects; D000893:Anti-Inflammatory Agents / Q000009:adverse effects; D001569:Benzodiazepines / Q000009:adverse effects; D002121:Calcium Channel Blockers / Q000009:adverse effects; D003875:Drug Eruptions / Q000453:epidemiology*; D004347:Drug Interactions; D004636:Emergency Service, Hospital; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D012044:Regression Analysis; D012307:Risk Factors
D000806:Angiotensin-Converting Enzyme Inhibitors; D000893:Anti-Inflammatory Agents; D002121:Calcium Channel Blockers; D001569:Benzodiazepines