Actonel - General Information

Actonel is a bisphosphonate used to strengthen bone, treat or prevent osteoporosis, and treat Paget's disease of bone.


Pharmacology of Actonel

Actonel is a pyridinyl bisphosphonate that inhibits osteoclast-mediated bone resorption and modulates bone metabolism and is indicated for the treatment and prevention of osteoporosis in postmenopausal women.


Actonel for patients


Actonel Interactions

No specific drug-drug interaction studies were performed. Risedronate is not metabolized and does not induce or inhibit hepatic microsomal drug-metabolizing enzymes (Cytochrome P450).

Calcium Supplements/Antacids

Co-administration of ACTONEL and calcium, antacids, or oral medications containing divalent cations will interfere with the absorption of ACTONEL.

Hormone Replacement Therapy

One study of about 500 early postmenopausal women has been conducted to date in which treatment with ACTONEL (5 mg/day) plus estrogen replacement therapy was compared to estrogen replacement therapy alone. Exposure to study drugs was approximately 12 to 18 months and the primary endpoint was change in BMD. If considered appropriate, ACTONEL may be used concomitantly with hormone replacement therapy.

Aspirin/Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Of over 5700 patients enrolled in the ACTONEL Phase 3 osteoporosis studies, aspirin use was reported by 31% of patients, 24% of whom were regular users (3 or more days per week). Forty-eight percent of patients reported NSAID use, 21% of whom were regular users. Among regular aspirin or NSAID users, the incidence of upper gastrointestinal adverse experiences in ACTONEL-treated patients (24.5%) was similar to that in placebo-treated patients (24.8%).

H2 Blockers and Proton Pump Inhibitors (PPIs)

Of over 5700 patients enrolled in the ACTONEL Phase 3 osteoporosis studies, 21% used H2 blockers and/or PPIs. Among these patients, the incidence of upper gastrointestinal adverse experiences in the ACTONEL-treated patients was similar to that in placebo-treated patients.

Drug/Laboratory Test Interactions

Bisphosphonates are known to interfere with the use of bone-imaging agents. Specific studies with ACTONEL have not been performed.


Actonel Contraindications

· Hypocalcemia

· Known hypersensitivity to any component of this product

· Inability to stand or sit upright for at least 30 minutes


Additional information about Actonel

Actonel Indication: For the treatment of Paget's disease of the bone (osteitis deformans), postmenopausal and glucocorticoid-induced osteoporosis
Mechanism Of Action: The action of risedronate on bone tissue is based partly on its affinity for hydroxyapatite, which is part of the mineral matrix of bone. Actonel also targets farnesyl pyrophosphate (FPP) synthase. Nitrogen-containing bisphosphonates (such as pamidronate, alendronate, risedronate, ibandronate and zoledronate) appear to act as analogues of isoprenoid diphosphate lipids, thereby inhibiting FPP synthase, an enzyme in the mevalonate pathway. Inhibition of this enzyme in osteoclasts prevents the biosynthesis of isoprenoid lipids (FPP and GGPP) that are essential for the post-translational farnesylation and geranylgeranylation of small GTPase signalling proteins. This activity inhibits osteoclast activity and reduces bone resorption and turnover. In postmenopausal women, it reduces the elevated rate of bone turnover, leading to, on average, a net gain in bone mass.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Risedronate
Synonyms: Risedronate sodium; Risedronic acid
Drug Category: Antiresorptives; Bisphosphonates; Antihypocalcemic Agents
Drug Type: Small Molecule; Approved
Other Brand Names containing Risedronate: Actonel;
Absorption: Rapid absorption (~1 hr) after an oral dose, occurs throughout the upper gastrointestinal tract
Toxicity (Overdose): Side effects include abdominal pain, anxiety, back pain, belching, bladder irritation, bone disorders and pain, bronchitis, bursitis, cataracts, chest pain, colitis, constipation, depression, diarrhea, difficulty breathing, dizziness, dry eyes, eye infection, flu-like symptoms, gas, headache, high blood pressure, infection, insomnia, itching, joint disorders and pain, leg cramps, muscle pain, muscle weakness, nausea, neck pain, nerve pain, pain, pneumonia, rash, ringing in ears, sinus problems, sore throat, stomach bleeding, stuffy or runny nose, swelling, tendon problems, tumor, ulcers, urinary tract infection, vertigo, vision problems, and weakness.
Protein Binding: ~24%
Biotransformation: No evidence found for metabolization of risedronate in humans or mammals
Half Life: 1.5 hours
Dosage Forms of Actonel: Tablet Oral
Chemical IUPAC Name: (1-hydroxy-1-phosphono-2-pyridin-3-ylethyl)phosphonic acid
Chemical Formula: C7H11NO7P2
Risedronate on Wikipedia:
Organisms Affected: Humans and other mammals