Ibandronic acid osteoporosis drug. Patient taking a tablet of the drug ibandronic acid (ibandronate sodium). This drug is used to treat and prevent osteoporosis (brittle bone disease) in post-menopausal women. It belongs to a class of drugs called bisphosphonates. It inhibits the action of bone cells that degrade and reabsorb bone (osteoclasts), therefore slowing the loss of bone mass. It also increases bone mass.