title: Efficacy and safety of risedronate 150 mg once a month in the treatment of postmenopausal osteoporosis.
abstract: BACKGROUND
  Risedronate has been shown to be effective in the treatment of postmenopausal osteoporosis when given orally in daily or weekly doses or on 2 consecutive days per month. This randomized, double-blind, multi-center study was designed to assess the efficacy and safety of a single 150 mg risedronate once-a-month oral dose compared with the 5 mg daily regimen.
  
  
  METHODS
  Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg daily (n=642) or 150 mg once a month (followed by daily placebo) (n=650) in a double-blind fashion for 2 years. Study drug was taken on an empty stomach at least 30 min before breakfast. Bone mineral density, bone turnover markers, fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine bone mineral density after 1 year.
  
  
  RESULTS
  538 patients in the daily group (83.8%) and 556 patients in the once-a-month group (85.5%) completed 1 year. The mean percent change in lumbar spine bone mineral density was 3.4% (95% confidence interval, 3.03% to 3.82%) in the daily group and 3.5% (95% confidence interval, 3.15% to 3.93%) in the once-a-month group. The difference between groups was -0.1% (95% confidence interval, -0.51% to 0.27%). The once-a-month regimen was determined to be non-inferior to the daily regimen based on prospectively defined criteria. The mean percent changes in bone mineral density at sites in the hip (total proximal femur, femoral neck, femoral trochanter) were also similar in both dose groups, as were the changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the 2 treatment groups. Both regimens were well tolerated; the percent of patients who withdrew from treatment as a result of an adverse event was 9.5% in the daily group and 8.6% in the once-a-month group.
  
  
  CONCLUSIONS
  Risedronate 150 mg once a month is similar in efficacy and safety to daily dosing and may provide an alternative for patients who prefer once-a-month oral dosing.
authors.affiliation: INSERM Research Unit 831 and University of Lyon, Lyon, France. delmas@lyon.inserm.fr
authors.forename: Pierre D
authors.initials: PD
authors.lastname: Delmas
authors.forename: Michael R
authors.initials: MR
authors.lastname: McClung
authors.forename: José R
authors.initials: JR
authors.lastname: Zanchetta
authors.forename: Artur
authors.initials: A
authors.lastname: Racewicz
authors.forename: Christian
authors.initials: C
authors.lastname: Roux
authors.forename: Claude-Laurent
authors.initials: CL
authors.lastname: Benhamou
authors.forename: Zulema
authors.initials: Z
authors.lastname: Man
authors.forename: Rachelle A
authors.initials: RA
authors.lastname: Eusebio
authors.forename: John F
authors.initials: JF
authors.lastname: Beary
authors.forename: David E
authors.initials: DE
authors.lastname: Burgio
authors.forename: Ellen
authors.initials: E
authors.lastname: Matzkin
authors.forename: Steven
authors.initials: S
authors.lastname: Boonen
mesh_terms: D015519:Bone Density / Q000187:drug effects; D064420:Drug-Related Side Effects and Adverse Reactions; D012968:Etidronic Acid / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D000068296:Risedronic Acid; D013997:Time Factors
chemical_list: D000068296:Risedronic Acid; D012968:Etidronic Acid