ZOLEDRONIC ACID

ZOLEDRONIC ACID
(zo-le-dron'ic)
Reclast, Zometa
Classifications: bisphosphonate; regulator, bone metabolism;
Therapeutic: bone metabolism regulator
Prototype: Etidronate disodium
Pregnancy Category: D

Availability

4 mg, 5 mg injection

Action

Zoledronic acid inhibits various stimulatory factors of osteoclastic activity produced by bone tumors. It also induces osteoclast apoptosis.

Therapeutic Effect

Zoledronic acid blocks osteoclastic resorption of bone, thus reducing the amount of calcium released from bone.

Uses

Treatment of hypercalcemia of malignancy, multiple myeloma, and bony metastases from solid tumors, Paget's disease (Reclast), postmenopausal osteoporosis (Reclast).

Contraindications

Hypersensitivity to zoledronic acid or other bisphosphonates; preexisting hypocalcemia; serum creatinine of 0.5 mg/dL; pregnancy (category D); lactation.

Cautious Use

Aspirin-sensitive asthma; cancer chemotherapy, corticosteroid therapy; renal and/or hepatic impairment; renal failure; dental work; concurrent administration of aminoglycosides, or loop diuretics; multiple myeloma; older adults. Safety and effectiveness of zoledronic acid in children have not been established.

Route & Dosage

Hypercalcemia of Malignancy (Zometa)
Adult: IV 4 mg over a minimum of 15 min. May consider retreatment if serum calcium has not returned to normal, may repeat after 7 d

Multiple Myeloma and Bony Metastases from Solid Tumors (Zometa)
Adult: IV 4 mg over a minimum of 15 min q3–4wk

Osteoporosis (Reclast)
Adult: IV 5 mg infusion once per year

Paget's Disease (Reclast)
Adult: IV 5 mg dose, retreatment may be necessary

Renal Impairment (Zometa)
Cl_cr 50–60 mL/min: 3.5 mg; 40–49 mL/min: 3.3 mg; 30–39 mL/min: 3.0 mg; <30 mL/min: do not use

Renal Impairment (Reclast)
Do not use if Cl_cr <35 mL/min.

Administration

Intravenous

Do not administer to anyone who is dehydrated or suspected of being dehydrated. Consult physician.
Do not administer zoledronic acid unless patient is adequately rehydrated.
Do not administer until serum creatinine values have been evaluated by the physician.

PREPARE: IV Infusion: Injection Concentrate: Withdraw required dose from the 4 mg/5 mL vial and dilute in 100 mL of D5W or NS. DO NOT use lactated Ringer's solution. ??If not used immediately, refrigerate. The total time between reconstitution and end of infusion must not exceed 24 h.

ADMINISTER: IV Infusion: Infuse a single dose over NO LESS than 15 min.

INCOMPATIBILITIES Solution/additive and Y-site: Do not mix or infuse with calcium-containing solutions (e.g., lactated Ringer's).

Store at 2°–8° C (36°–46° F) following dilution.
Must be completely infused within 24 h of reconstitution.

Adverse Effects (≥1%)

Body as a Whole: Fever, flu-like syndrome, redness and swelling at injection site, asthenia, chest pain, leg edema, mucositis, rigors. CNS: Insomnia, anxiety, confusion, agitation, headache, somnolence. CV: Hypotension. GI: Nausea, vomiting, constipation, abdominal pain, anorexia, dysphagia. Hematologic: Anemia, granulocytopenia, thrombocytopenia, pancytopenia. Metabolic: Hypophosphatemia, hypokalemia, hypomagnesemia, hypocalcemia, dehydration. Musculoskeletal: Skeletal pain, arthralgias, osteonecrosis of the jaw in cancer patients. Respiratory: Dyspnea, cough, pleural effusion. Skin: Alopecia, dermatitis. Urogenital: Renal deterioration (increase in S_cr).

Interactions

Drug: loop diuretics may increase risk of hypocalcemia; thalidomide and other nephrotoxic drugs may increase risk of renal toxicity.

Pharmacokinetics

Onset: 4–10 d. Duration: 3–4 wk. Metabolism: Not metabolized. Elimination: In urine. Half-Life: 146 h.

Nursing Implications

Assessment & Drug Effects

Lab tests: Baseline renal function tests prior to each dose and periodically thereafter; periodic ionized calcium or corrected serum calcium levels, serum phosphate and magnesium, electrolytes, CBC with differential, Hct and Hgb.
Notify physician immediately of deteriorating renal function as indicated by rising serum creatinine levels over baseline value.
Withhold subsequent doses of zoledronic acid if serum creatinine is not within 10% of the baseline value. Consult physician.
Monitor closely patient's hydration status. Note that loop diuretics should be used with caution due to the risk of hypocalcemia.
Monitor for S&S of bronchospasm in aspirin-sensitive asthma patients; notify physician immediately.

Patient & Family Education

Maintain adequate daily fluid intake. Consult with physician for guidelines.
Report unexplained weakness, tiredness, irritation, muscle pain, insomnia, or flu-like symptoms.
Use reliable means of birth control to prevent pregnancy. If you suspect you are pregnant, contact physician immediately.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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