OBJECTIVES: Oral bisphosphonate treatment is standard therapy for PMO, but certain patients are unsuitable for this therapy due to intolerance or dosing difficulties. Such patients may receive ‘off-label' unlicensed IV bisphosphonates, typically IV pamidronate in the UK. Ibandronate is the first IV preparation licensed for PMO and this study provides an economic analysis of IV ibandronate in this setting. METHODS: IV ibandronate is administered as a 3mg IV ‘push' lasting 15-30 seconds every 3 months, and priced approximately £27/mg. IV pamidronate (30-60mg) is infused (10-60mg/hour) every 3 months, and priced at approximately £2/mg across the preparations available. A cost-minimisation analysis was undertaken to demonstrate the economic case for IV ibandronate, since based on a review of the clinical evidence base and licensing status, IV ibandronate is assumed to provide at least as much clinical benefit as IV pamidronate. This analysis included referenced NHS costs for drug acquisition and administration (pharmacy preparation, disposables and nurse time required for infusions/IV administration) and compared IV ibandronate to the ‘average' use of IV pamidronate – 45mg infused at 20mg/hour. Due to the range of doses and infusion types used for IV pamidronate, sensitivity analyses were conducted. RESULTS: Ibandronate is cost-saving on acquisition (£18/patient/year) and particularly on administration (£407/patient/year). The total cost-saving associated with a switch from pamidronate to ibandronate is approximately £425/patient/year and driven primarily by lower administration costs. Under sensitivity analysis, ibandronate remains cost-saving even when the comparator is generic 30mg pamidronate, pamidronate is infused at the maximum rate, or when nurses manage several patients' infusions simultaneously. CONCLUSIONS: Ibandronate IV injection is cost-saving for the NHS compared to IV pamidronate infusion, under a range of realistic scenarios. When this finding is considered alongside IV ibandronate's evidence base and licence for PMO, it is concluded that ibandronate IV injection clearly offers value for money.