AREDIA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AREDIA (AREDIA).
Bisphosphonate that inhibits osteoclast-mediated bone resorption by binding to hydroxyapatite crystals in bone and inhibiting osteoclast activity.
| Metabolism | Not metabolized; excreted unchanged in urine. |
| Excretion | Primarily eliminated unchanged via renal excretion (about 30-40% of administered dose within 24 hours); remainder sequestered in bone and slowly released over months. Biliary/fecal excretion is negligible (<1%). |
| Half-life | Multiphasic; terminal half-life is approximately 300 hours (range 200-400 hours) reflecting slow release from bone. Clinically, this results in prolonged suppression of bone resorption lasting weeks after a single dose. |
| Protein binding | Approximately 54% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Steady-state Vd is approximately 0.4-0.6 L/kg, indicating extensive distribution to bone and soft tissues; rapid uptake by bone mineral. |
| Bioavailability | Intravenous: 100% (only route). Oral bioavailability is <1% and clinically irrelevant; no oral formulation available. |
| Onset of Action | IV infusion: Reduction in serum calcium begins within 24-48 hours, with maximal effect by 4-7 days. Oral: not applicable; AREDIA is only given intravenously. |
| Duration of Action | Therapeutic effect on hypercalcemia typically lasts for 2-3 weeks after a single dose. Inhibition of bone resorption may persist for several weeks to months due to drug accumulation in bone. |
90 mg intravenously over 2 hours every 3-4 weeks for hypercalcemia of malignancy; 90 mg intravenously over 2 hours every 4 weeks for osteolytic bone metastases of breast cancer or multiple myeloma.
| Dosage form | INJECTABLE |
| Renal impairment | For CrCl >50 mL/min: no adjustment; CrCl 30-50 mL/min: reduce dose to 60 mg; CrCl <30 mL/min: not recommended (no data). |
| Liver impairment | No specific adjustment recommended; use caution in severe hepatic impairment due to limited data. |
| Pediatric use | Safety and efficacy not established for pediatric patients. |
| Geriatric use | No specific dose adjustment required; monitor renal function and fluid status carefully owing to age-related decreased glomerular filtration rate. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AREDIA (AREDIA).
| Breastfeeding | It is not known whether pamidronate is excreted in human milk. The M/P ratio is unknown. Due to potential for skeletal toxicity and hypocalcemia in the nursing infant, advise women not to breastfeed during treatment and for a period after the last dose (at least 1-2 weeks based on half-life). |
| Teratogenic Risk | Pregnancy Category D. May cause fetal harm when administered to a pregnant woman. In animal reproduction studies, bisphosphonates cause fetal skeletal retardation and decreased fetal weight. There is no adequate and well-controlled study in pregnant women; however, postmarketing reports indicate fetal skeletal abnormalities (e.g., shortened long bones) when bisphosphonates are used during pregnancy. First trimester exposure may be associated with neonatal hypocalcemia and skeletal effects. Second and third trimester exposure may increase risk for fetal skeletal mineralization defects. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to pamidronate or other bisphosphonates","Hypocalcemia"]
| Precautions | ["Renal impairment","Osteonecrosis of the jaw","Hypocalcemia","Severe musculoskeletal pain","Atypical femur fractures"] |
| Food/Dietary | No specific food interactions. Avoid excessive intake of calcium or vitamin D supplements unless prescribed. Maintain adequate hydration. |
| Clinical Pearls | Monitor serum calcium, phosphate, and magnesium regularly. Aredia (pamidronate) is contraindicated in severe renal impairment (CrCl <30 mL/min). Administer as a slow IV infusion (over at least 2 hours for 90 mg dose; 4 hours for metastatic bone disease) to reduce risk of nephrotoxicity. Hydrate adequately before infusion. Assess for osteonecrosis of the jaw (ONJ) and perform dental exam before therapy. Not recommended in pregnancy and lactation. |
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| Fetal Monitoring | Monitor serum calcium, phosphate, and magnesium levels before each dose and periodically during therapy, especially in pregnant patients. Monitor renal function (serum creatinine) prior to each dose. In pregnant patients, monitor fetal growth and skeletal development via ultrasound. Monitor neonatal calcium levels after delivery if exposure occurred. |
| Fertility Effects | In animal studies, pamidronate caused reduced fertility and impaired embryo-fetal development at doses comparable to human exposure. In humans, no formal fertility studies are available. Potential effects on fertility are unknown; however, bisphosphonates may delay or impair oocyte maturation and implantation due to calcium homeostasis disruption. |
| Patient Advice | You must have regular blood tests to monitor calcium, phosphate, and magnesium levels. · Report any bone pain, jaw pain, or swelling in your mouth immediately. · Maintain good oral hygiene and undergo a dental check-up before starting treatment. · Drink plenty of fluids before and after each infusion. · This drug is not safe during pregnancy; use effective contraception if applicable. |