Psychotropic drugs and the risk of fractures in old age: a prospective population-based study.
BACKGROUND
There is evidence that the use of any psychotropic and the concomitant use of two or more benzodiazepines are related to an increased risk of fractures in old age. However, also controversial results exist. The aim was to describe associations between the use of a psychotropic drug, or the concomitant use of two or more of these drugs and the risk of fractures in a population aged 65 years or over.


METHODS
This study was a part of a prospective longitudinal population-based study carried out in the municipality of Lieto, South-Western Finland. The objective was to describe gender-specific associations between the use of one psychotropic drug [benzodiazepine (BZD), antipsychotic (AP) or antidepressant (AD)] or the concomitant use of two or more psychotropic drugs and the risk of fractures in a population 65 years or over. Subjects were participants in the first wave of the Lieto study in 1990-1991, and they were followed up until the end of 1996. Information about fractures confirmed with radiology reports in 1,177 subjects (482 men and 695 women) during the follow-up was collected from medical records. Two follow-up periods (three and six years) were used, and previously found risk factors of fractures were adjusted as confounding factors separately for men and women. The Poisson regression model was used in the analyses.


RESULTS
The concomitant use of two or more BZDs and the concomitant use of two or more APs were related to an increased risk of fractures during both follow-up periods after adjusting for confounding factors in men. No similar associations were found in women.


CONCLUSIONS
The concomitant use of several BZDs and that of several APs are associated with an increase in the risk of fractures in older men. Our findings show only risk relations. We cannot draw the conclusion that these drug combinations are causes of fractures.
Nurminen
Janne
J
Family Medicine, Institute of Clinical Medicine, University of Turku, Lemminkäisenkatu 1, Turku 20014, Finland. janurm@utu.fi
Puustinen
Juha
J
Piirtola
Maarit
M
Vahlberg
Tero
T
Kivelä
Sirkka-Liisa
SL
D000368:Aged; D000928:Antidepressive Agents / Q000009:adverse effects; D014150:Antipsychotic Agents / Q000009:adverse effects; D001569:Benzodiazepines / Q000009:adverse effects*; D004359:Drug Therapy, Combination / Q000009:adverse effects; D005260:Female; D005387:Finland; D050723:Fractures, Bone / Q000209:etiology*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011619:Psychotropic Drugs / Q000009:adverse effects*; D012044:Regression Analysis; D012306:Risk; D012737:Sex Factors
D000928:Antidepressive Agents; D014150:Antipsychotic Agents; D011619:Psychotropic Drugs; D001569:Benzodiazepines