Oral Dosing Recommendations: Alendronate and Risendronate to Prevent and Treat Osteoporosis and Paget Disease

Dosage

Table 4 lists the dosing recommendations for risedronate and alendronate. The drugs should be given orally, at least 30 minutes before the first food or drink of the day other than water. The drugs should be swallowed while the patient is in an upright position and should be taken with a full glass of water. Patients should not lie down for 30 minutes after taking risedronate or alendronate.

Table 4:
Oral Dosing Recommendations for Alendronate and Risedronate

*Not FDA-approved for this indication
† If the patient is postmenopausal and is not taking estrogen

Once-weekly dosing

Of note, Merck, Inc. recently received FDA approval to market two new dosage strengths of alendronate for once-weekly dosing: a 35-mg tablet for the prevention of postmenopausal osteoporosis and a 70-mg tablet for the treatment of osteoporosis.

This modified dosing schedule for treatment is based on a recent study by Schnitzer et al(16) comparing the efficacy and safety of oral doses of alendronate 70 mg once a week (n = 519), 35 mg twice a week (n = 369), and 10 mg once every day (n = 370). In a 1-year, double-blind, multi-center study of postmenopausal women with osteoporosis, all three regimens produced similar increases in bone mineral density at the lumbar spine, total hip, femoral neck, trochanter, and total body. All three regimens were well tolerated with no statistically significant differences in the most commonly reported upper GI events, including abdominal pain, nausea, dyspepsia, and acid regurgitation. Also, a trend towards a lower incidence of esophageal, gastric, or duodenal adverse effects was observed with once-a-week and twice-a-week dosing vs daily dosing. The authors concluded that alendronate 70 mg once a week is a more convenient alternative to daily dosing and may enhance compliance.

Given the apparent advantages of once-weekly alendronate dosing, Woodson et al(17) reported a trial of risedronate 30 mg once-a-week for 12 months in 13 postmenopausal women with osteoporosis who did not tolerate FDA-approved therapies. Increases in bone mineral density from baseline were seen in the lumbar spine, femoral neck, and total hip, and the treatment was well tolerated. Statistical analysis was not available.

Cost

Table 5 compares the average wholesale prices of alendronate and risedronate in dosages used for osteoporosis prevention and treatment. Risedronate is slightly less expensive. However, improved patient compliance and tolerability of the once-weekly form of alendronate could offset this cost difference. Further studies are necessary to directly compare adverse effects of risedronate and alendronate and to clinically evaluate the modified once-weekly dosing regimen.

Table 5:
Average Wholesale Prices for Alendronate and Risedronate

*Taken once daily for osteorporosis prevention or treatment
†Taken once a week for osteoporosis prevention or treatment
‡Taken once daily for Paget disease
Prices from 2001 Drug Topics Red Book. Montvale, NJ; Medical Economics Company, 2001.

References

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