Actonel is a prescription drug used to treat osteoporosis, with the active ingredient risedronate. It works by increasing bone density to prevent fractures. Actonel comes in various dosage forms, and the specific dosage should be determined based on the patient's condition and doctor's advice. For postmenopausal women, typical dosages include 5 mg daily, 35 mg weekly, 75 mg monthly (twice a month), or 150 mg monthly. For osteoporosis caused by glucocorticoids, the recommended dosage is 5 mg daily. For men, the recommended dosage is 35 mg weekly. For Paget's disease of bone, the recommended dosage is 30 mg daily for 2 months. Actonel should be taken on an empty stomach in the morning with a full glass of water. Do not lie down for at least 30 minutes after taking it, and avoid eating or drinking anything else. For missed doses, do not double up; take the missed dose as soon as possible or skip it, depending on the dosage schedule.