Investigators have found, in a head-to-head comparison, that injectable teriparatide (Forteo) is able to increase bone mineral density (BMD) by as much as twice when compared to oral alendronate (Fosamax).

Teriparatide is associated with greater improvements in BMD at the spine and the hip, as per Kenneth Saag, M.D., of the University of Alabama at Birmingham and his colleagues.

From Medpagetoday.com:

“In our study, teriparatide was associated with greater increases in [BMD] at the spine and hip and with significantly fewer new vertebral fractures,” Dr. Saag’s group wrote. But the dropout rate for adverse effects was twice as high for those taking teriparatide.

Only one out of 171 evaluable patients receiving teriparatide had radiographic evidence of a vertebral fracture, while 10 of 165 evaluable patients on alendronate had such fractures (P=0.004).

Nonvertebral fractures occurred at similar rates with the two treatments (5.6% versus 3.7%, P=0.36). BMD in the total hip increased with both drugs, though less dramatically than in the lumbar spine. Teriparatide increased hip BMD by 3.8% while it rose 2.4% in the alendronate group. The advantage for teriparatide was significant (P<0.01). Significantly more patients in the teriparatide group had at least one elevated serum calcium measurement > 10.5 mg/dL (18% versus 5.7%, P<0.001) and there was a tendency toward more patients with at least one measurement > 11 mg/dL (3.8% versus 1%, P=0.06).

Teriparatide is a recombinant peptide drug, based on a portion of the parathyroid hormone protein. Earlier studies had indicated that it leads to increased BMD.

Philip N. Sambrook, M.D., of the University of Sydney, remarked that teriparatide is expected to be taken as a potential first-line therapy for osteoporosis induced by steroids by as findings of Saag and colleagues.