Drug-drug interactions related to hospital admissions in older adults: a prospective study of 1000 patients.
OBJECTIVE
To investigate the frequency, nature, and side effects of drug-drug interactions (DDI) in a group of geriatric inpatients.


METHODS
Study of drugs administered at home in the 2 weeks preceding hospitalization.


METHODS
Evaluation of patients admitted to a geriatric unit from the emergency unit.


METHODS
One thousand inpatients more than 70 years of age (83.0 +/- 7.1 years), admitted consecutively to a hospital for acute illness.


METHODS
All possible two by two combinations of drugs administered at home were considered to determine whether these associations could lead to a DDI and whether side effects resulted from these interactions.


RESULTS
Five hundred thirty-eight patients were exposed to 1087 DDI. The most frequently involved drugs were cardiovascular and psychotropic medications. There were 189 side effects observed in 130 patients. The most frequent side effects were neuropsychological impairment, arterial hypotension, and acute renal failure. The number of side effects did not differ between the 66 contraindicated drug associations and the 1021 associations that only required precautionary use.


CONCLUSIONS
DDI frequently lead to side effects in older adults. Classifications of DDI must be adapted to increased DDI sensitivity in this population. Nevertheless the frequency of side effects might be reduced by limiting the prescription of the most frequent and dangerous DDI.
Doucet
J
J
Department of Clinical Gerontology, Centre Hospitalier Universitaire, Rouen, France.
Chassagne
P
P
Trivalle
C
C
Landrin
I
I
Pauty
M D
MD
Kadri
N
N
Ménard
J F
JF
Bercoff
E
E
D000368:Aged; D000369:Aged, 80 and over; D002317:Cardiovascular Agents / Q000009:adverse effects*; D004347:Drug Interactions; D005260:Female; D015577:Geriatric Assessment; D006760:Hospitalization; D006801:Humans; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D011619:Psychotropic Drugs / Q000009:adverse effects*
D002317:Cardiovascular Agents; D011619:Psychotropic Drugs