Ibandronate sodium is a new drug that's marketed under the brand name Boniva.
This drug belongs to the bisphosphonate class, a group of drugs that delay or stop the natural process of bone tissue dissolution or resorption, leading to the maintenance or increase in bone density and strength.
Why it is prescribed
As a bisphosphonate, ibandronate sodium (Boniva) is prescribed for the prevention or treatment of osteoporosis in postmenopausal women. This drug is usually given to prevent bone loss due to osteoporosis; or when this condition has already developed, ibandronate sodium is taken to slow the rate of bone thinning, thus lowering the risk of fractures.
Unlabeled uses of this drug include treatment of metastatic bone disease in breast cancer.
How the drug works
Ibandronate sodium's effect on bone tissue is related to its affinity for hydroxyapatite, a component of the bone matrix. This drug inhibits certain cells called osteoclasts from breaking down and nibbling at bone tissues, thus preventing bone resorption and turnover. In postmenopausal women, ibandronate sodium decreases the rate of bone turnover, which can then result in a net increase in bone mass.
Available drug forms
Ibandronate sodium comes in 2.5 mg and 150 mg tablets. It is also available in 1 mg/ml injections.
When it is contraindicated
This drug is contraindicated in:
Patients who cannot sit or stand erect for at least 60 minutes (tablets);
Patients with untreated hypocalcemia, or low blood calcium level (injections, tablets);
Allergic reaction to any ingredient of the drug (injections, tablets)
Absorption, distribution, metabolism and elimination
Ibandronate sodium is absorbed in the upper portion of the gastrointestinal tract. Unabsorbed drug is excreted unchanged in the feces while the absorbed ibandronate goes to the bone tissues and binds with the bone matrix to exert its therapeutic effect.
This drug is not metabolized in the liver and does not inhibit the activity of cytochrome P450 system, a group of enzymes responsible for catalyzing various key biochemical reactions in the body. Ibandronate that is not taken from the circulation through bone resorption is excreted unchanged by the kidney through the urine.
Special considerations
When taking ibandronate sodium, you need to consider the following:
Tablets come in two strengths (2.5 mg for once-a-day dosing, and 150 mg for once-a-month dosing). So be sure to check the label carefully to avoid confusion.
Take ibandronate tablets with plain water only, and not with any form of liquid. Taking this drug with other liquids or with food will lessen its absorption and efficacy.
Injection form of ibandronate should be administered intravenously (IV) by a health care provider.
Pre-filled syringes are to be used only once; any unused portion must be discarded.
Injections must not be mixed with calcium- containing solutions or any other drugs given intravenously.
If a dose is missed, ibandronate injection must be administered as soon as possible.
Subsequent injections must be given every 3 months from the date of last injection; and should not be more often than once every 3 months.
Calcium and vitamin D supplements must be taken.
Side Effects
Generally, ibandronate sodium (Boniva) causes mild and moderate side effects, the most common of which include: diarrhea, pain in arms or legs, and stomach upset (dyspepsia). It can also cause heartburn (esophagitis), pain or difficulty swallowing (dysphagia), as well as stomach and esophageal ulcers.
However, you should stop taking ibandronate sodium and call your doctor immediately if you experience the following:
Pain or difficulty swallowing
Chest pain
Severe heartburn or persistent heartburn
Ibandronate sodium is also associated with less common and short-lasting side effects such as mild flu-like symptoms. There may be other reported side effects associated with this drug, so for more detailed information, you need to consult your health care provider.
Precautions and drug interactions
As this drug is eliminated by the kidney, it must be administered with caution in patients with renal impairment or kidney problems.
Pharmacokinetic study of this drug has not been done in patients below 18 years of age.
Drugs and products containing calcium, magnesium, aluminum, and iron are likely to hamper the absorption of ibandronate. A pharmacokinetic interaction study also revealed that ranitidine, a histamine (H2) blocker, raised the oral bioavailability of 10 mg ibandronate by approximately 20 percent, though this increase is not considered to have clinical significance.