Prescribing-label excerpts
Pamidronate Disodium
Reference for: Pamidronate Disodium. Source presentation: injection. Source route: intravenous.
Mechanism of action
The principal pharmacologic action of pamidronate disodium is inhibition of bone resorption. Although the mechanism of antiresorptive action is not completely understood, several factors are thought to contribute to this action. Pamidronate disodium adsorbs to calcium phosphate (hydroxyapatite) crystals in bone and may block dissolution of this mineral component of bone. In vitro, pamidronate disodium inhibited osteoclast activity. In animal studies, pamidronate disodium inhibited bone resorption, but did not inhibit bone formation and mineralization. In animal tumor models, pamidronate disodium inhibited the increased osteoclast activity induced by tumors.
Pharmacokinetics
The body retention of pamidronate was 54 ± 16% (mean ± standard deviation) of the dose over 120 hours.
The elimination half-life is 28 ± 7 hours (mean ± standard deviation). Total and renal clearances of pamidronate were 107 ± 50 mL/min and 49 ± 28 mL/min, respectively. The rate of elimination from bone has not been determined.
After administration of 30, 60, and 90 mg of pamidronate disodium over 4 hours, and 90 mg of pamidronate disodium over 24 hours, 46 ± 16% (mean ± standard deviation) of the drug was excreted unchanged in the urine within 120 hours. Cumulative urinary excretion was linearly related to dose.
Selected passages from the cited U.S. prescribing label. The studies concern the source product and populations named in each passage; they do not establish Walter-product bioequivalence, an approved indication, or the kinetics of another fixed combination. Tables and the full prescribing information remain available in the source.
Source: DailyMed: Pamidronate Disodium — injection
Reference accessed . Label revision: 2025-12-15.
