Use of antidepressant drugs and risk of osteoporotic and non-osteoporotic fractures.
OBJECTIVE
Both tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) have been associated with an increased risk of fractures. The serotonin transporter (5-HTT) has been located in the bone and may play a role in bone physiology. We assessed the association between antidepressant drug use, categorized in a therapeutical-based way and on basis of their affinity for the 5-HTT, and the risk of both osteoporotic and non-osteoporotic fractures.


METHODS
A case-control study was conducted using the PHARMO RLS. Cases were patients with a first hospital admission for a fracture during the study period. Up to four controls were matched to each case on gender, age, geographical area, and index date.


RESULTS
We identified 16,717 cases, of whom 59.5% had an osteoporotic fracture, and 61,517 controls. Compared to no use, current use of SSRIs was associated with a statistically significant increased risk of osteoporotic fractures (OR 1.95, 95% CI 1.69-2.26), as was current use of TCAs and non-SSRI/non-TCA antidepressant drugs (ORs 1.37, 95% CI 1.16-1.63 and 1.40, 95% CI 1.06-1.85, respectively). The risk of an osteoporotic fracture was statistically significantly higher for antidepressants with a high affinity for the 5-HTT (OR 1.86, 95% CI 1.63-2.13) compared to antidepressants with a medium or low affinity (OR 1.43, 95% CI 1.19-1.72 (medium) and OR 1.32 95% CI 0.98-1.79 (low) (p<0.05 for trend). The risk of non-osteoporotic fractures did not show the same trend.


CONCLUSIONS
The extent of affinity for the 5-HTT may contribute to the increased risk of osteoporotic fractures related to antidepressant drug use. The pharmacological mechanism-based classification could to be an appropriate alternative for traditional classification to study the association between the use of antidepressants and the risk of fractures.
Verdel
Bertha Maria
BM
Division of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands. b.m.verdel@uu.nl
Souverein
Patrick C
PC
Egberts
Toine C G
TC
van Staa
Tjeerd P
TP
Leufkens
Hubert G M
HG
de Vries
Frank
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000009:adverse effects*; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects*; D016022:Case-Control Studies; D003863:Depression / Q000188:drug therapy; D050723:Fractures, Bone / Q000139:chemically induced*; D006801:Humans; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000139:chemically induced*; D012307:Risk Factors; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects*; D055815:Young Adult
D000928:Antidepressive Agents; D000929:Antidepressive Agents, Tricyclic; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors