Ibandronate

Products

Ibandronate is commercially available as film-coated tablets (monthly tablets containing 150 mg of ibandronic acid) and as a solution for injection (Bonviva, generics). The daily tablets containing 2.5 mg of active ingredient are no longer available. This article refers to oral and monthly osteoporosis therapy. Ibandronate is also used in tumor treatment. Ibandronate was approved in the United States in 2003 and in many countries and the EU in 2004. It is also marketed as Boniva in some countries.

Structure and properties

Ibandronate is the sodium salt and monohydrate of ibandronic acid. It is therefore also known as ibandronate sodium monohydrate (C9H24NNaO8P2, Mr = 359.2 g/mol). Ibandronate exists as a white powder that is highly soluble in water. It belongs structurally to the nitrogen-containing bisphosphonates. Bisphosphonates are analogs of pyrophosphate in which the oxygen between the phosphates (P-O-P) has been replaced by a carbon atom (P-C-P).

Effects

Ibandronate (ATC M05BA06) increases bone density and mechanical strength of bone. It inhibits osteoclast activity and reduces bone resorption. The effects are based on affinity for hydroxyapatite and binding to the bone surface. The half-life is in the range of 10 to 72 hours. Ibandronate is deposited in bone and remains there for decades.

Indications

For the treatment of osteoporosis in postmenopausal women. To reduce the risk of fractures of the spine.

Dosage

According to the SmPC. The tablets are taken once a month and on the same day, for example, on the 15th of each month. There are some important points to keep in mind when taking the tablets:

  • Taking in the morning 60 minutes before the first intake of food or liquid.
  • Do not take with calcium or other medications and supplements (interval of at least 60 minutes).
  • Take the tablets unchewed with a glass of tap water (> 2 dl) sitting upright or standing.
  • Do not lie down for 60 minutes after administration.
  • Use only tap water and not mineral water for ingestion.
  • Do not suck or chew tablets.

The reasons for these instructions are, on the one hand, the deep oral bioavailability, the risk for interactions (see below) and, on the other hand, the risk for mucosal irritation. To help patients remember to take the medication each month, a calendar entry may be recommended. The long dosing interval may be an advantage for treatment adherence.

Contraindications

  • Hypersensitivity
  • Uncorrected hypocalcemia (low calcium level).
  • Esophageal abnormalities that delay esophageal emptying.
  • Patients who cannot stand or sit upright for at least 60 minutes.
  • Pregnancy, lactation
  • Children under 18 years

Full precautions can be found in the drug label.

Interactions

Ibandronate has a very low oral bioavailability of only 0.6%. Foods taken at the same time, beverages such as mineral water and milk (except tap water), calcium, aluminum, magnesium, and iron may further decrease the poor bioavailability. Ibandronate does not interact with CYP450 isoenzymes and is excreted primarily by the kidneys. The portion not absorbed into the body is eliminated in the stool. Other drugs that irritate the mucous membranes of the digestive tract may increase adverse effects.

Adverse effects

The most common possible adverse effects include: