The safety and efficacy of Zoledronic Acid Injection in the treatment of hypercalcemia associated with hyperparathyroidism or with other non-tumor-related conditions have not been established.
Bags of Zoledronic Acid Injection ready-to-use solution for infusion contain overfill allowing for the administration of 100 mL of solution (equivalent to 4 mg zoledronic acid). This solution is ready to use and may be administered directly to the patient without further preparation. For single-use only.
Caution: After removing the overwrap check for minute leaks by squeezing the inner bag firmly. If leaks are found, discard container as sterility may be compromised. Use only if solution is clear and the container is undamaged.
- Close flow control clamp of administration set.
- Remove cover from port at bottom of container.
- Insert piercing pin of administration set into port with a twisting motion until the pin is firmly seated. NOTE: See full directions on administration set carton.
- Suspend container from hanger.
- Squeeze and release drip chamber to establish proper fluid level in chamber during infusion of Zoledronic Acid Injection.
- Open flow control clamp to expel air from set. Close clamp.
- Regulate rate of administration with flow control clamp.
Hypercalcemia of Malignancy
The safety of Zoledronic Acid Injection was studied in 185 patients with hypercalcemia of malignancy (HCM) who received either Zoledronic Acid Injection 4 mg given as a 5-minute intravenous infusion (n=86) or pamidronate 90 mg given as a 2-hour intravenous infusion (n=103). The population was aged 33-84 years, 60% male and 81% Caucasian, with breast, lung, head and neck, and renal cancer as the most common forms of malignancy. NOTE: pamidronate 90 mg was given as a 2-hour intravenous infusion. The relative safety of pamidronate 90 mg given as a 2-hour intravenous infusion compared to the same dose given as a 24-hour intravenous infusion has not been adequately studied in controlled clinical trials.
Renal Toxicity
Administration of Zoledronic Acid Injection 4 mg given as a 5-minute intravenous infusion has been shown to result in an increased risk of renal toxicity, as measured by increases in serum creatinine, which can progress to renal failure. The incidence of renal toxicity and renal failure has been shown to be reduced when Zoledronic Acid Injection 4 mg is given as a 15-minute intravenous infusion. Zoledronic Acid Injection should be administered by intravenous infusion over no less than 15 minutes [see Warnings and Precautions (5.3), Dosage and Administration (2.4)].
The most frequently observed adverse reactions were fever, nausea, constipation, anemia, and dyspnea (see Table 4).
Table 4 provides adverse reactions that were reported by 10% or more of the 189 patients treated with Zoledronic Acid Injection 4 mg or pamidronate 90 mg from the two HCM trials. Adverse reactions are listed regardless of presumed causality to study drug.
Table 4: Percentage of Patients with Adverse Reactions greater than or equal to 10% Reported in Hypercalcemia of Malignancy Clinical Trials by Body System
| Zoledronic Acid Injection 4 mg n (%) | Pamidronate 90 mg n (%) |
| Patients Studied | | | | |
| Total No. of Patients Studied
| 86
| (100)
| 103
| (100)
|
| Total No. of Patients with any AE
| 81
| (94)
| 95
| (92)
|
| Body as a Whole | | | | |
| Fever
| 38
| (44)
| 34
| (33)
|
| Progression of Cancer
| 14
| (16)
| 21
| (20)
|
| Cardiovascular | | | | |
| Hypotension
| 9
| (11)
| 2
| (2)
|
| Digestive | | | | |
| Nausea
| 25
| (29)
| 28
| (27)
|
| Constipation
| 23
| (27)
| 13
| (13)
|
| Diarrhea
| 15
| (17)
| 17
| (17)
|
| Abdominal Pain
| 14
| (16)
| 13
| (13)
|
| Vomiting
| 12
| (14)
| 17
| (17)
|
| Anorexia
| 8
| (9)
| 14
| (14)
|
| Hemic and Lymphatic System | | | | |
| Anemia
| 19
| (22)
| 18
| (18)
|
| Infections | | | | |
| Moniliasis
| 10
| (12)
| 4
| (4)
|
| Laboratory Abnormalities | | | | |
| Hypophosphatemia
| 11
| (13)
| 2
| (2)
|
| Hypokalemia
| 10
| (12)
| 16
| (16)
|
| Hypomagnesemia
| 9
| (11)
| 5
| (5)
|
| Musculoskeletal | | | | |
| Skeletal Pain
| 10
| (12)
| 10
| (10)
|
| Nervous | | | | |
| Insomnia
| 13
| (15)
| 10
| (10)
|
| Anxiety
| 12
| (14)
| 8
| (8)
|
| Confusion
| 11
| (13)
| 13
| (13)
|
| Agitation
| 11
| (13)
| 8
| (8)
|
| Respiratory | | | | |
| Dyspnea
| 19
| (22)
| 20
| (19)
|
| Coughing
| 10
| (12)
| 12
| (12)
|
| Urogenital | | | | |
| Urinary Tract Infection
| 12
| (14)
| 15
| (15)
|
The following adverse reactions from the two controlled multicenter HCM trials (n=189) were reported by a greater percentage of patients treated with Zoledronic Acid Injection 4 mg than with pamidronate 90 mg and occurred with a frequency of greater than or equal to 5% but less than 10%. Adverse reactions are listed regardless of presumed causality to study drug: asthenia, chest pain, leg edema, mucositis, dysphagia, granulocytopenia, thrombocytopenia, pancytopenia, nonspecific infection, hypocalcemia, dehydration, arthralgias, headache and somnolence.
Cases of rash, pruritus, and chest pain have been reported following treatment with Zoledronic Acid Injection.
Acute Phase Reaction
Within three days after Zoledronic Acid Injection administration, an acute phase reaction has been reported in patients, with symptoms including pyrexia, fatigue, bone pain and/or arthralgias, myalgias, chills, and influenza-like illness. These symptoms usually resolve within a few days. Pyrexia has been the most commonly associated symptom, occurring in 44% of patients.
Mineral and Electrolyte Abnormalities
Electrolyte abnormalities, most commonly hypocalcemia, hypophosphatemia, and hypomagnesemia, can occur with bisphosphonate use.
Grade 3 and Grade 4 laboratory abnormalities for serum creatinine, serum calcium, serum phosphorus, and serum magnesium observed in two clinical trials of Zoledronic Acid Injection in patients with HCM are shown in Table 5 and 6.
Table 5: Grade 3 Laboratory Abnormalities for Serum Creatinine, Serum Calcium, Serum Phosphorus, and Serum Magnesium in Two Clinical Trials in Patients with HCM
| Grade 3 |
| Laboratory Parameter | Zoledronic Acid Injection 4 mg | Pamidronate 90 mg |
| n/N | (%) | n/N | (%) |
| Serum Creatinine1 | 2/86
| (2%)
| 3/100
| (3%)
|
| Hypocalcemia2 | 1/86
| (1%)
| 2/100
| (2%)
|
| Hypophosphatemia3 | 36/70
| (51%)
| 27/81
| (33%)
|
| Hypomagnesemia4 | 0/71
| —
| 0/84
| —
|
| | | | |
Table 6: Grade 4 Laboratory Abnormalities for Serum Creatinine, Serum Calcium, Serum Phosphorus, and Serum Magnesium in Two Clinical Trials in Patients with HCM
|
|
|
|
| Grade 4 |
| Laboratory Parameter | Zoledronic Acid Injection 4 mg | Pamidronate 90 mg |
| n/N | (%) | n/N | (%) |
| Serum Creatinine1 | 0/86
| —
| 1/100
| (1%)
|
| Hypocalcemia2 | 0/86
| —
| 0/100
| —
|
| Hypophosphatemia3 | 1/70
| (1%)
| 4/81
| (5%)
|
| Hypomagnesemia4 | 0/71
| —
| 1/84
| (1%)
|
Injection Site Reactions
Local reactions at the infusion site, such as redness or swelling, were observed infrequently. In most cases, no specific treatment is required and the symptoms subside after 24-48 hours.
Ocular Adverse Reactions
Ocular inflammation such as uveitis and scleritis can occur with bisphosphonate use, including Zoledronic Acid Injection. No cases of iritis, scleritis, or uveitis were reported during these clinical trials. However, cases have been seen in postmarketing use [see Adverse Reactions (6.2)].
Multiple Myeloma and Bone Metastases of Solid Tumors
The safety analysis includes patients treated in the core and extension phases of the trials. The analysis includes the 2042 patients treated with Zoledronic Acid Injection 4 mg, pamidronate 90 mg, or placebo in the three controlled multicenter bone metastases trials, including 969 patients completing the efficacy phase of the trial, and 619 patients that continued in the safety extension phase. Only 347 patients completed the extension phases and were followed for 2 years (or 21 months for the other solid tumor patients). The median duration of exposure for safety analysis for Zoledronic Acid Injection 4 mg (core plus extension phases) was 12.8 months for breast cancer and multiple myeloma, 10.8 months for prostate cancer, and 4.0 months for other solid tumors.
Table 7 describes adverse reactions that were reported by 10% or more of patients. Adverse reactions are listed regardless of presumed causality to study drug.
Table 7: Percentage of Patients with Adverse Reactions greater than or equal to 10% Reported in Three Bone Metastases Clinical Trials by Body System
| Zoledronic Acid Injection 4 mg | Pamidronate 90 mg | Placebo |
| n (%) | n (%) | n (%) |
| Patients Studied | | | |
Total No. of Patients Total No. of Patients with any AE Blood and Lymphatic Anemia Neutropenia Thrombocytopenia Gastrointestinal | 1031 1015
344 124 102
| (100) (98)
(33) (12) (10)
| 556 548
175 83 53
| (100) (99)
(32) (15) (10)
| 455 445
128 35 20
| (100) (98)
(28) (8) (4)
|
Nausea Vomiting Constipation Diarrhea Abdominal Pain Dyspepsia Stomatitis Sore Throat General Disorders and Administration Site | 476 333 320 249 143 105 86 82
| (46) (32) (31) (24) (14) (10) (8) (8)
| 266 183 162 162 81 74 65 61
| (48) (33) (29) (29) (15) (13) (12) (11)
| 171 122 174 83 48 31 14 17
| (38) (27) (38) (18) (11) (7) (3) (4)
|
Fatigue Pyrexia Weakness Edema Lower Limb Rigors Infections | 398 328 252 215 112
| (39) (32) (24) (21) (11)
| 240 172 108 126 62
| (43) (31) (19) (23) (11)
| 130 89 114 84 28
| (29) (20) (25) (19) (6)
|
Urinary Tract Infection Upper Respiratory Tract Infection Metabolism | 124 101
| (12) (10)
| 50 82
| (9) (15)
| 41 30
| (9) (7)
|
Anorexia Weight Decreased Dehydration Appetite Decreased
| 231 164 145 130
| (22) (16) (14) (13)
| 81 50 60 48
| (15) (9) (11) (9)
| 105 61 59 45
| (23) (13) (13) (10)
|
| Musculoskeletal | | | | | | |
| Bone Pain
| 569
| (55)
| 316
| (57)
| 284
| (62)
|
| Myalgia
| 239
| (23)
| 143
| (26)
| 74
| (16)
|
| Arthralgia
| 216
| (21)
| 131
| (24)
| 73
| (16)
|
| Back Pain
| 156
| (15)
| 106
| (19)
| 40
| (9)
|
| Pain in Limb
| 143
| (14)
| 84
| (15)
| 52
| (11)
|
| Neoplasms | | | | | | |
| Malignant Neoplasm Aggravated
| 205
| (20)
| 97
| (17)
| 89
| (20)
|
| Nervous | | | | | | |
| Headache
| 191
| (19)
| 149
| (27)
| 50
| (11)
|
| Dizziness (excluding vertigo)
| 180
| (18)
| 91
| (16)
| 58
| (13)
|
| Insomnia
| 166
| (16)
| 111
| (20)
| 73
| (16)
|
| Paresthesia
| 149
| (15)
| 85
| (15)
| 35
| (8)
|
| Hypoesthesia
| 127
| (12)
| 65
| (12)
| 43
| (10)
|
| Psychiatric | | | | | | |
| Depression
| 146
| (14)
| 95
| (17)
| 49
| (11)
|
| Anxiety
| 112
| (11)
| 73
| (13)
| 37
| (8)
|
| Confusion
| 74
| (7)
| 39
| (7)
| 47
| (10)
|
| Respiratory | | | | | | |
| Dyspnea
| 282
| (27)
| 155
| (28)
| 107
| (24)
|
| Cough
| 224
| (22)
| 129
| (23)
| 65
| (14)
|
| Skin | | | | | | |
| Alopecia
| 125
| (12)
| 80
| (14)
| 36
| (8)
|
| Dermatitis
| 114
| (11)
| 74
| (13)
| 38
| (8)
|
Grade 3 and Grade 4 laboratory abnormalities for serum creatinine, serum calcium, serum phosphorus, and serum magnesium observed in three clinical trials of Zoledronic Acid Injection in patients with bone metastases are shown in Tables 8 and 9.
Table 8: Grade 3 Laboratory Abnormalities for Serum Creatinine, Serum Calcium, Serum Phosphorus, and Serum Magnesium in Three Clinical Trials in Patients with Bone Metastases
|
|
|
|
|
|
| Grade 3 |
| Laboratory Parameter | Zoledronic Acid Injection 4 mg | Pamidronate 90 mg | Placebo |
| | | |
| n/N | (%) | n/N | (%) | n/N | (%) |
| Serum Creatinine
1*
| 7/529
| (1%)
| 4/268
| (2%)
| 4/241
| (2%)
|
| Hypocalcemia2 | 6/973
| (<1%)
| 4/536
| (<1%)
| 0/415
| —
|
| Hypophosphatemia3 | 115/973
| (12%)
| 38/537
| (7%)
| 14/415
| (3%)
|
| Hypermagnesemia4 | 19/971
| (2%)
| 2/535
| (<1%)
| 8/415
| (2%)
|
| Hypomagnesemia5 | 1/971
| (<1%)
| 0/535
| —
| 1/415
| (<1%)
|
Table 9: Grade 4 Laboratory Abnormalities for Serum Creatinine, Serum Calcium, Serum Phosphorus, and Serum Magnesium in Three Clinical Trials in Patients with Bone Metastases
|
|
|
|
|
|
| Grade 4 |
| Laboratory Parameter | Zoledronic Acid Injection 4 mg | Pamidronate 90 mg | Placebo |
| | | |
| n/N | (%) | n/N | (%) | n/N | (%) |
| Serum Creatinine
1*
| 2/529
| (<1%)
| 1/268
| (<1%)
| 0/241
| —
|
| Hypocalcemia2 | 7/973
| (<1%)
| 3/536
| (<1%)
| 2/415
| (<1%)
|
| Hypophosphatemia3 | 5/973
| (<1%)
| 0/537
| —
| 1/415
| (<1%)
|
| Hypermagnesemia4 | 0/971
| —
| 0/535
| —
| 2/415
| (<1%)
|
| Hypomagnesemia5 | 2/971
| (<1%)
| 1/535
| (<1%)
| 0/415
| —
|
Among the less frequently occurring adverse reactions (less than 15% of patients), rigors, hypokalemia, influenza-like illness, and hypocalcemia showed a trend for more reactions with bisphosphonate administration (Zoledronic Acid Injection 4 mg and pamidronate groups) compared to the placebo group.
Less common adverse reactions reported more often with Zoledronic Acid Injection 4 mg than pamidronate included decreased weight, which was reported in 16% of patients in the Zoledronic Acid Injection 4 mg group compared with 9% in the pamidronate group. Decreased appetite was reported in slightly more patients in the Zoledronic Acid Injection 4 mg group (13%) compared with the pamidronate (9%) and placebo (10%) groups, but the clinical significance of these small differences is not clear.
Renal Toxicity
In the bone metastases trials, renal deterioration was defined as an increase of 0.5 mg/dL for patients with normal baseline creatinine (less than 1.4 mg/dL) or an increase of 1.0 mg/dL for patients with an abnormal baseline creatinine (greater than or equal to 1.4 mg/dL). The following are data on the incidence of renal deterioration in patients receiving Zoledronic Acid Injection 4 mg over 15 minutes in these trials (see Table 10).
Table 10: Percentage of Patients with Treatment-Emergent Renal Function Deterioration by Baseline Serum Creatinine*
|
|
| Patient Population/Baseline Creatinine | |
| Multiple Myeloma and Breast Cancer | Zoledronic Acid Injection 4 mg | Pamidronate 90 mg |
| n/N | (%) | n/N | (%) |
| Normal
| 27/246
| (11%)
| 23/246
| (9%)
|
| Abnormal
| 2/26
| (8%)
| 2/22
| (9%)
|
| Total
| 29/272
| (11%)
| 25/268
| (9%)
|
| Solid Tumors | Zoledronic Acid Injection 4 mg | Placebo |
| n/N | (%) | n/N | (%) |
| Normal
| 17/154
| (11%)
| 10/143
| (7%)
|
| Abnormal
| 1/11
| (9%)
| 1/20
| (5%)
|
| Total
| 18/165
| (11%)
| 11/163
| (7%)
|
| Prostate Cancer | Zoledronic Acid Injection 4 mg | Placebo |
| n/N | (%) | n/N | (%) |
| Normal
| 12/82
| (15%)
| 8/68
| (12%)
|
| Abnormal
| 4/10
| (40%)
| 2/10
| (20%)
|
| Total
| 16/92
| (17%)
| 10/78
| (13%)
|
The risk of deterioration in renal function appeared to be related to time on study, whether patients were receiving Zoledronic Acid Injection (4 mg over 15 minutes), placebo, or pamidronate.
In the trials and in postmarketing experience, renal deterioration, progression to renal failure, and dialysis have occurred in patients with normal and abnormal baseline renal function, including patients treated with 4 mg infused over a 15-minute period. There have been instances of this occurring after the initial Zoledronic Acid Injection dose.
Osteonecrosis of the Jaw
Cases of osteonecrosis (primarily involving the jaw but also of other anatomical sites including hip, femur and external auditory canal) have been reported predominantly in cancer patients treated with intravenous bisphosphonates including Zoledronic Acid Injection. Many of these patients were also receiving chemotherapy and corticosteroids which may be a risk factor for ONJ. Caution is advised when Zoledronic Acid Injection is administered with anti-angiogenic drugs as an increased incidence of ONJ has been observed with concomitant use of these drugs. Data suggests a greater frequency of reports of ONJ in certain cancers, such as advanced breast cancer and multiple myeloma. The majority of the reported cases are in cancer patients following invasive dental procedures, such as tooth extraction. It is therefore prudent to avoid invasive dental procedures as recovery may be prolonged [see Warnings and Precautions (5.4)].
Acute Phase Reaction
Within three days after Zoledronic Acid Injection administration, an acute phase reaction has been reported, with symptoms including pyrexia, fatigue, bone pain and/or arthralgias, myalgias, chills, influenza-like illness and arthritis with subsequent joint swelling; these symptoms usually resolve within three days of onset, but resolution could take up to 7 to 14 days. However, some of these symptoms have been reported to persist for a longer duration.
Musculoskeletal Pain
Severe and occasionally incapacitating bone, joint, and/or muscle pain has been reported with bisphosphonate use [see Warnings and Precautions (5.5)].
Atypical Subtrochanteric and Diaphyseal Femoral Fractures
Atypical subtrochanteric and diaphyseal femoral fractures have been reported with bisphosphonate therapy, including Zoledronic Acid Injection [see Warnings and Precautions (5.6)].
Ocular Adverse Reactions
Cases of uveitis, scleritis, episcleritis, conjunctivitis, iritis, and orbital inflammation including orbital edema have been reported during postmarketing use. In some cases, symptoms resolved with topical steroids.
Hypersensitivity Reactions
There have been reports of allergic reaction with intravenous zoledronic acid including angioedema and bronchoconstriction. Cases of anaphylactic reaction/shock have also been reported. Cases of Stevens-Johnson syndrome and toxic epidermal necrolysis have also been reported.
Additional adverse reactions reported in postmarketing use include:
CNS: taste disturbance, hyperesthesia, tremor; Special Senses: blurred vision; uveitis; Gastrointestinal: dry mouth; Skin: Increased sweating; Musculoskeletal: muscle cramps; Cardiovascular: hypertension, bradycardia, hypotension (associated with syncope or circulatory collapse primarily in patients with underlying risk factors); Respiratory: bronchospasms, interstitial lung disease (ILD) with positive rechallenge; Renal: hematuria, proteinuria, acquired Fanconi syndrome; General Disorders and Administration Site: weight increase, influenza-like illness (pyrexia, asthenia, fatigue or malaise) persisting for greater than 30 days; Laboratory Abnormalities: hyperkalemia, hypernatremia, hypocalcemia (cardiac arrhythmias and neurologic adverse events including seizures, tetany and numbness have been reported due to severe hypocalcemia).
Pregnancy Category D
[see Warnings and Precautions (5.9)]
There are no adequate and well-controlled studies of Zoledronic Acid Injection in pregnant women. Zoledronic Acid Injection may cause fetal harm when administered to a pregnant woman. Bisphosphonates, such as Zoledronic Acid Injection, are incorporated into the bone matrix and are gradually released over periods of weeks to years. The extent of bisphosphonate incorporation into adult bone, and hence, the amount available for release back into the systemic circulation, is directly related to the total dose and duration of bisphosphonate use. Although there are no data on fetal risk in humans, bisphosphonates do cause fetal harm in animals, and animal data suggest that uptake of bisphosphonates into fetal bone is greater than into maternal bone. Therefore, there is a theoretical risk of fetal harm (e.g., skeletal and other abnormalities) if a woman becomes pregnant after completing a course of bisphosphonate therapy. The impact of variables such as time between cessation of bisphosphonate therapy to conception, the particular bisphosphonate used, and the route of administration (intravenous versus oral) on this risk has not been established. If this drug is used during pregnancy or if the patient becomes pregnant while taking or after taking this drug, the patient should be apprised of the potential hazard to the fetus.
In female rats given subcutaneous doses of zoledronic acid of 0.01, 0.03, or 0.1 mg/kg/day beginning 15 days before mating and continuing through gestation, the number of stillbirths was increased and survival of neonates was decreased in the mid- and high-dose groups (greater than or equal to 0.2 times the human systemic exposure following an intravenous dose of 4 mg, based on an AUC comparison). Adverse maternal reactions were observed in all dose groups (with a systemic exposure of greater than or equal to 0.07 times the human systemic exposure following an intravenous dose of 4 mg, based on an AUC comparison) and included dystocia and periparturient mortality in pregnant rats allowed to deliver. Maternal mortality may have been related to drug-induced inhibition of skeletal calcium mobilization, resulting in periparturient hypocalcemia. This appears to be a bisphosphonate-class effect.
In pregnant rats given a subcutaneous dose of zoledronic acid of 0.1, 0.2, or 0.4 mg/kg/day during gestation, adverse fetal reactions were observed in the mid- and high-dose groups (with systemic exposures of 2.4 and 4.8 times, respectively, the human systemic exposure following an intravenous dose of 4 mg, based on an AUC comparison). These adverse reactions included increases in pre- and postimplantation losses, decreases in viable fetuses, and fetal skeletal, visceral, and external malformations. Fetal skeletal effects observed in the high-dose group included unossified or incompletely ossified bones, thickened, curved, or shortened bones, wavy ribs, and shortened jaw. Other adverse fetal reactions observed in the high-dose group included reduced lens, rudimentary cerebellum, reduction or absence of liver lobes, reduction of lung lobes, vessel dilation, cleft palate, and edema. Skeletal variations were also observed in the low-dose group (with systemic exposure of 1.2 times the human systemic exposure following an intravenous dose of 4 mg, based on an AUC comparison). Signs of maternal toxicity were observed in the high-dose group and included reduced body weights and food consumption, indicating that maximal exposure levels were achieved in this study.
In pregnant rabbits given subcutaneous doses of zoledronic acid of 0.01, 0.03, or 0.1 mg/kg/day during gestation (less than or equal to 0.5 times the human intravenous dose of 4 mg, based on a comparison of relative body surface areas), no adverse fetal reactions were observed. Maternal mortality and abortion occurred in all treatment groups (at doses greater than or equal to 0.05 times the human intravenous dose of 4 mg, based on a comparison of relative body surface areas). Adverse maternal reactions were associated with, and may have been caused by, drug-induced hypocalcemia.
Distribution
Single or multiple (every 28 days) 5-minute or 15-minute infusions of 2, 4, 8, or 16 mg Zoledronic Acid Injection were given to 64 patients with cancer and bone metastases. The post-infusion decline of zoledronic acid concentrations in plasma was consistent with a triphasic process showing a rapid decrease from peak concentrations at end of infusion to less than 1% of Cmax 24 hours post-infusion with population half-lives of t1/2α 0.24 hours and t1/2β 1.87 hours for the early disposition phases of the drug. The terminal elimination phase of zoledronic acid was prolonged, with very low concentrations in plasma between Days 2 and 28 post-infusion, and a terminal elimination half-life t1/2γ of 146 hours. The area under the plasma concentration versus time curve (AUC0-24h) of zoledronic acid was dose proportional from 2-16 mg. The accumulation of zoledronic acid measured over three cycles was low, with mean AUC0-24h ratios for cycles 2 and 3 versus 1 of 1.13 ± 0.30 and 1.16 ± 0.36, respectively.
In vitro and ex vivo studies showed low affinity of zoledronic acid for the cellular components of human blood, with a mean blood to plasma concentration ratio of 0.59 in a concentration range of 30 ng/mL to 5000 ng/mL. In vitro, the plasma protein binding is low, with the unbound fraction ranging from 60% at 2 ng/mL to 77% at 2000 ng/mL of zoledronic acid.
Metabolism
Zoledronic acid does not inhibit human P450 enzymes in vitro. Zoledronic acid does not undergo biotransformation in vivo. In animal studies, less than 3% of the administered intravenous dose was found in the feces, with the balance either recovered in the urine or taken up by bone, indicating that the drug is eliminated intact via the kidney. Following an intravenous dose of 20 nCi 14C-zoledronic acid in a patient with cancer and bone metastases, only a single radioactive species with chromatographic properties identical to those of parent drug was recovered in urine, which suggests that zoledronic acid is not metabolized.
Excretion
In 64 patients with cancer and bone metastases, on average (± SD) 39 ± 16% of the administered zoledronic acid dose was recovered in the urine within 24 hours, with only trace amounts of drug found in urine post-Day 2. The cumulative percent of drug excreted in the urine over 0-24 hours was independent of dose. The balance of drug not recovered in urine over 0-24 hours, representing drug presumably bound to bone, is slowly released back into the systemic circulation, giving rise to the observed prolonged low plasma concentrations. The 0-24 hour renal clearance of zoledronic acid was 3.7 ± 2.0 L/h.
Zoledronic acid clearance was independent of dose but dependent upon the patient's creatinine clearance. In a study in patients with cancer and bone metastases, increasing the infusion time of a 4-mg dose of zoledronic acid from 5 minutes (n=5) to 15 minutes (n=7) resulted in a 34% decrease in the zoledronic acid concentration at the end of the infusion ([mean ± SD] 403 ± 118 ng/mL versus 264 ± 86 ng/mL) and a 10% increase in the total AUC (378 ± 116 ng x h/mL versus 420 ± 218 ng x h/mL). The difference between the AUC means was not statistically significant.
Special Populations
Pediatrics
Zoledronic Acid Injection is not indicated for use in children [see Use in Specific Populations (8.4)].
Geriatrics
The pharmacokinetics of zoledronic acid were not affected by age in patients with cancer and bone metastases who ranged in age from 38 years to 84 years.
Race
Population pharmacokinetic analyses did not indicate any differences in pharmacokinetics among Japanese and North American (Caucasian and African American) patients with cancer and bone metastases.
Hepatic Insufficiency
No clinical studies were conducted to evaluate the effect of hepatic impairment on the pharmacokinetics of zoledronic acid.
Renal Insufficiency
The pharmacokinetic studies conducted in 64 cancer patients represented typical clinical populations with normal to moderately impaired renal function. Compared to patients with normal renal function (N=37), patients with mild renal impairment (N=15) showed an average increase in plasma AUC of 15%, whereas patients with moderate renal impairment (N=11) showed an average increase in plasma AUC of 43%. Limited pharmacokinetic data are available for Zoledronic Acid Injection in patients with severe renal impairment (creatinine clearance less than 30 mL/min). Based on population PK/PD modeling, the risk of renal deterioration appears to increase with AUC, which is doubled at a creatinine clearance of 10 mL/min. Creatinine clearance is calculated by the Cockcroft-Gault formula:
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CrCl=[140-age (years)] x weight (kg) {x 0.85 for female patients}
[72 x serum creatinine (mg/dL)]
Zoledronic Acid Injection systemic clearance in individual patients can be calculated from the population clearance of Zoledronic Acid Injection, CL (L/h)=6.5(CrCl/90)0.4. These formulae can be used to predict the Zoledronic Acid Injection AUC in patients, where CL=Dose/AUC0-∞. The average AUC0-24 in patients with normal renal function was 0.42 mg•h/L and the calculated AUC0-∞ for a patient with creatinine clearance of 75 mL/min was 0.66 mg•h/L following a 4-mg dose of Zoledronic Acid Injection. However, efficacy and safety of adjusted dosing based on these formulae have not been prospectively assessed [see Warnings and Precautions (5.3)].
Drugs with Same Active Ingredient or in the Same Drug Class
- Inform patients not to take Reclast or other bisphosphonates during the course of their Zoledronic Acid Injection therapy [see Warnings and Precautions (5.1)].
Renal Impairment
- Instruct patients to tell their doctor if they have kidney problems before being given Zoledronic Acid Injection.
- Inform patients of the importance of getting their blood tests (serum creatinine) during the course of their Zoledronic Acid Injection therapy [see Warnings and Precautions (5.3)].
Osteonecrosis of the Jaw