Safety and efficacy of menatetrenone in children with osteogenesis imperfecta

Background: Osteogenesis imperfecta (OI) is an inherited connective tissue disorder with defective bone quality leading to increased bone fragility and low bone mass. Menatetrenone has been shown to reduce bone mineral density (BMD) loss as well as the incidence of fractures in patients with osteoporosis.

Objectives: We investigated the effects of menatetrenone in five prepubertal children with OI.

Methods: All patients had been treated with intravenous pamidronate for four to 42 months prior to enrollment in this study. Pamidronate was discontinued at least two months before starting 15 milligrams per day of oral menatetrenone. Menatetrenone was given for 12 months. BMD was measured at baseline and one year after menatetrenone treatment.

Results: During one year of menatetrenone treatment, the incidence of fractures was 1.0 (0.0-2.0) times/year, which was not significantly different from the fracture rate of 1.2 (0.0-1.5) times/year during pamidronate treatment. However, it significantly decreased compared with the fracture rate of 10.4 (2.7-47.6) times/year before pamidronate treatment (P=0.043). After one year of menatetrenone, BMD of lumbar spine and left hip significantly increased in three and two patients, respectively. However, one patient showed a significant decrease in BMD in both regions. Noteworthy, none of the patients developed adverse side effects during menatetrenone treatment.

Conclusions: One-year menatetrenone could maintain the decreased fracture rate of intravenous pamidronate in prepubertal OI patients. No adverse effects were observed. Larger and longer studies to determine the benefit of oral menatetrenone as adjunctive treatment in OI patients are warranted.