Effects of cyclical etidronate combined with calcitriol versus cyclical etidronate alone on spine and femoral neck bone mineral density in postmenopausal osteoporotic women.
OBJECTIVE
Few data are available on the effects of combination therapy for the treatment of osteoporosis. The aim of this study was to compare the effects of intermittent cyclical etidronate (E) therapy alone with a combination of cyclical etidronate and calcitriol (E + C) on spine and femoral neck bone mineral density (BMD) at one year.


METHODS
Postmenopausal women with at least one non-traumatic vertebral fracture or z score < -1.5 were randomly allocated to an E group (each cycle = oral etidronate 400 mg daily for 14 days followed by calcium 500 mg daily for 76 days) or an E + C group (as for E plus oral calcitriol 0.5 microgram daily). Lumbar spine and femoral neck BMDs were measured by dual energy x ray absorptiometry at baseline and at one year. The study design did not contain a placebo group.


RESULTS
The mean % increase in lumbar spine BMD was 5.2% (95% CI = 3.4 to 7.0) in the E + C group (n = 24), which was significantly greater than the 2.7% (95% CI = 1.3 to 4.1) increase in the E group (n = 23) (p < 0.05). The femoral neck BMD in the E + C group increased by 2.0% (95% CI = 0.8 to 3.2), which was significantly different from the E group where there was a -0.4% (95% CI = -2.4 to 1.6) change (p = 0.046).


CONCLUSIONS
These data show that a combination of cyclical etidronate and calcitriol is better than cyclical etidronate alone in terms of changes in BMD at both spine and femoral neck sites. Although further data are needed on fracture efficacy, this study suggests that combination therapies have additive therapeutic potential that may exceed that expected from their theoretical mode of action.
Department of Integrated Medicine, City Hospital, Nottingham.
T
T
Masud
B
B
Mulcahy
A V
AV
Thompson
S
S
Donnelly
R W
RW
Keen
D V
DV
Doyle
T D
TD
Spector
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects*; D002117:Calcitriol / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D012968:Etidronic Acid / Q000627:therapeutic use*; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000503:physiopathology
D002117:Calcitriol; D012968:Etidronic Acid