Dopaminergic drugs and the risk of hip or femur fracture: a population-based case-control study.
CONCLUSIONS
The effect of dopaminergic medication on the risk of hip/femur fractures is not clear. Our results showed a nearly twofold increased risk of hip/femur fractures in current dopaminergic drug users. Concomitant use of antidepressants further increased this risk. Fracture risk assessment may be warranted in elderly users of dopaminergic drugs.


BACKGROUND
Dopaminergic drugs, often used in the treatment of Parkinson's disease, have several pharmacological effects that may increase or decrease the risk of falling and fractures. Thus, the effect of dopaminergic medication on the risk of hip/femur fractures is not clear. The objective of the study was to examine the effect of dopaminergic medication and concomitant use of psychotropics on the risk of hip/femur fractures taking into account the timing of dopaminergic drug use.


METHODS
A population-based case-control study in the PHARMO database was conducted for the period 1991 to 2002. Cases were patients aged 18 years and older with a first hip or femur fracture and matched to four control patients by year of birth, sex and geographical region.


RESULTS
The study population included 6,763 cases and 26,341 controls. Current use of dopaminergic drugs (1-30 days before the index date) was associated with an increased risk of hip/femur fractures compared to never use (OR(adj) 1.76, 95% CI = 1.39-2.22), but this excess risk rapidly dropped to baseline levels when treatment had been discontinued >1 year ago. Concomitant use of antidepressants among current dopaminergic drug users further increased the risk of hip/femur fractures (OR(adj) 3.51, 95% CI = 2.10-5.87) while there was no additional risk with concomitant use of other psychotropics.


CONCLUSIONS
Although the observed association between dopaminergic drugs and fracture risk may not be entirely causal, due to absence of information on the (severity of the) underlying disease, fracture risk assessment may be warranted in elderly users of dopaminergic drugs.
Department of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Universiteit Utrecht, P.O. Box 80082, 3508 TB, Utrecht, The Netherlands.
M E L
ME
Arbouw
K L L
KL
Movig
T P
TP
van Staa
A C G
AC
Egberts
P C
PC
Souverein
F
F
de Vries
D000293:Adolescent; D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000009:adverse effects; D016022:Case-Control Studies; D015259:Dopamine Agents / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D005264:Femoral Fractures / Q000139:chemically induced* / Q000453:epidemiology; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011619:Psychotropic Drugs / Q000009:adverse effects*; D012307:Risk Factors; D055815:Young Adult
D000928:Antidepressive Agents; D015259:Dopamine Agents; D011619:Psychotropic Drugs