Risedronate

Products

Risedronate is available as weekly 35 mg tablets and as 30 mg tablets (Actonel, generic). Actonel 5 mg and 75 mg tablets are off-label in many countries. Risedronate has been approved since 2000. Generic versions went on sale in 2012.

Structure and properties

Risedronate (C7H10NO7P2Na – 2.5 H2O, Mr = 350.1 g/mol) is a pyridinyl bisphosphonate. It is present in drugs as risedronate sodium hemipentahydrate, a white crystalline powder that is soluble in water.

Effects

Risedronate (ATC M05BA07) deposits in bone and inhibits bone resorption by inhibiting osteoclasts. In contrast, bone formation is preserved.

Indications

For the treatment of osteoporosis and Paget’s disease.

Dosage

According to the SmPC. Risedronate is usually administered for the treatment of osteoporosis in the form of the weekly tablets, taken once a week. The directions in the package insert must be followed carefully to allow optimal absorption of the active ingredient into the body and to avoid adverse effects.

Contraindications

Risedronate is contraindicated in hypersensitivity, hypocalcemia, inability to maintain an upright posture (standing or sitting) for at least 30 minutes, severe renal insufficiency, and during pregnancy and lactation. For complete precautions, see the drug label.

Interactions

Risedronate, like other bisphosphonates, has a low oral bioavailability of less than one percent. Foods and medications taken at the same time can further reduce absorption into the body. Therefore, drugs should always be taken on an empty stomach. Risedronate is not metabolized and does not interact with CYP450.

Adverse effects

The most common possible adverse effects include headache, musculoskeletal pain, constipation, dyspepsia, nausea, abdominal pain, and diarrhea.