ACTONEL (risedronate sodium tablets), manufactured by Procter & Gamble Pharmaceuticals, Inc is a pyridinyl bisphosphonate that inhibits osteoclast-mediated bone resorption and modulates bone metabolism.

It is mainly used in the prevention and treatment of osteoporosis in post menopausal women.

OSTEOPOROSIS:

It is a pathological condition which affects the bones by increasing their risk of fracture. In this condition, there is decrease in the Bone Mineral Density [BMD], which results in the alteration of the whole micro architecture of the bone. The World Health Organization [WHO] defines osteoporosis in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old healthy female average) as measured by DXA; the term "established osteoporosis" includes the presence of a fragility fracture

It is predominantly seen in women, especially postmenopausal women where it is termed as post menopausal osteoporosis. However it can also affect males, irrespective of the age and in the presence of certain chronic pathological conditions and some drugs like glucocorticoids where it is termed as steroid- or glucocorticoid-induced osteoporosis (SIOP or GIOP).

The underlying mechanism in all cases of osteoporosis is an imbalance between bone resorption and bone formation. In normal bone, there is constant matrix remodeling of bone; up to 10% of all bone mass may be undergoing remodeling at any point in time. The process takes place in bone multicellular units (BMUs) as first described by Frost in 1963. Bone is resorbed by osteoclast cells (which derive from the bone marrow), after which new bone is deposited by osteoblast cells.

The three main mechanisms by which osteoporosis develop are an inadequate peak bone mass (the skeleton develops insufficient mass and strength during growth), excessive bone resorption and inadequate formation of new bone during remodeling. Interplay of these three mechanisms underlies the development of fragile bone tissue.

Osteoporosis can be prevented with lifestyle advice and sometimes medication, and in people with osteoporosis treatment may involve lifestyle advice, preventing falls and medication (calcium, vitamin D, bisphosphonates and several others).

INDIACATIONS

• Treatment of Postmenopausal Osteoporosis

ACTONEL (risedronate sodium tablets) is indicated for the treatment of osteoporosis in postmenopausal women. In fact this is the main indication of ACTONEL In postmenopausal women with osteoporosis; it reduces the incidence of vertebral fractures and a composite endpoint of non vertebral osteoporosis-related fractures. In postmenopausal women with osteoporosis, ACTONEL increases Bone Mineral Density and reduces the incidence of vertebral fractures and a composite endpoint of non vertebral osteoporosis-related fractures.

• Prevention of Osteoporosis:

ACTONEL may be considered in postmenopausal women who are at risk of developing osteoporosis and for whom the desired clinical outcome is to maintain bone mass and to reduce the risk of fracture. The factors that are considered as high risk in postmenopausal females for Osteoporosis include

• positive family history for osteoporosis

• previous fracture,

• smoking,

• BMD (at least 1 SD below the pre menopausal mean),

• high bone turnover,

• thin body frame,

• Caucasian or Asian race,

• Early menopause.

• Osteoporosis in Men

ACTONEL is indicated for treatment to increase bone mass in men with osteoporosis.

• Glucocorticoid-Induced Osteoporosis

ACTONEL is indicated for the prevention and treatment of glucocorticoid-induced osteoporosis in men and women who are either initiating or continuing systemic glucocorticoid treatment (daily dosage of ≥ 7.5 mg prednisone or equivalent) for chronic diseases. Patients treated with glucocorticoids should receive adequate amounts of calcium and vitamin D.

• Paget's Disease

ACTONEL is indicated for treatment of Paget's disease of bone in men and women.

CONTRADICATIONS

• Hypocalcaemia

Known hypersensitivity to any component of this drug.

Inability to stand or sit upright for at least 30 minutes

SIDE EFFECTS

ACTONEL has a variety of side effects which cannot be predicted. These include Abdominal pain, , back pain, bone disorders and pain, cataracts, chest pain, constipation, , diarrhea, dry eyes, eye infection, headache, , infection, itching, joint disorders and pain, leg cramps, muscle pain, muscle weakness, nausea, ringing in ears, sore throat, stomach bleeding, stuffy or runny nose, swelling, tendon problems, tumor, ulcers, urinary tract infection, vertigo, vision problems, weakness

DOSAGE AND ADMINISTRATION

ACTONEL should be taken at least 30 minutes before the first food or drink of the day other than water. It should it taken in an upright position and after taking ACTONEL, the patient should stay in upright position for 30 minutes. This is just to ensure that that there is complete absorption of the drug

The recommended regimen for post menopausal women is:

• one 5 mg tablet orally, taken daily

or

• one 35 mg tablet orally, taken once a week

or

• one 75 mg tablet orally, taken on two consecutive days for a total of two tablets each month

or

• one 150 mg tablet orally, taken once a month

The recommended regimen for osteoporosis in men is:

• one 35 mg tablet orally, taken once a week

Recommended regimen for the treatment and prevention of Glucocorticoid-Induced Osteoporosis is

• one 5 mg tablet orally, taken daily

Treatment of Paget's disease

The recommended treatment regimen is 30 mg orally once daily for 2 months.