Pamidronate

INDICATIONS AND USAGE Hypercalcemia of Malignancy Pamidronate disodium, in conjunction with adequate hydration, is indicated for the treatment of moderate or severe hypercalcemia associated with malignancy, with or without bone metastases. Patients who have either epidermoid or non-epidermoid tumors respond to treatment with pamidronate disodium. Vigorous saline hydration, an integral part of hypercalcemia therapy, should be initiated promptly and an attempt should be made to restore the urine output to about 2 L/day throughout treatment. Mild or asymptomatic hypercalcemia may be treated with conservative measures (i.e., saline hydration, with or without loop diuretics). Patients should be hydrated adequately throughout the treatment, but overhydration, especially in those patients who have cardiac failure, must be avoided. Diuretic therapy should not be employed prior to correction of hypovolemia. The safety and efficacy of pamidronate disodium in the treatment of hypercalcemia associated with hyperparathyroidism or with other non-tumor-related conditions has not been established. Paget’s Disease Pamidronate disodium is indicated for the treatment of patients with moderate to severe Paget’s disease of bone. The effectiveness of pamidronate disodium was demonstrated primarily in patients with serum alkaline phosphatase ≥ 3 times the upper limit of normal. Pamidronate disodium therapy in patients with Paget’s disease has been effective in reducing serum alkaline phosphatase and urinary hydroxyproline levels by ≥ 50% in at least 50% of patients, and by ≥ 30% in at least 80% of patients. Pamidronate disodium therapy has also been effective in reducing these biochemical markers in patients with Paget’s disease who failed to respond, or no longer responded to other treatments. Osteolytic Bone Metastases of Breast Cancer and Osteolytic Lesions of Multiple Myeloma Pamidronate disodium is indicated, in conjunction with standard antineoplastic therapy, for the treatment of o

DOSAGE AND ADMINISTRATION Hypercalcemia of Malignancy Consideration should be given to the severity of as well as the symptoms of hypercalcemia. Vigorous saline hydration alone may be sufficient for treating mild, asymptomatic hypercalcemia. Overhydration should be avoided in patients who have potential for cardiac failure. In hypercalcemia associated with hematologic malignancies, the use of glucocorticoid therapy may be helpful. Moderate Hypercalcemia The recommended dose of pamidronate disodium in moderate hypercalcemia (corrected serum calcium* of approximately 12 to 13.5 mg/dL) is 60 to 90 mg given as a SINGLE DOSE, intravenous infusion over 2 to 24 hours. Longer infusions (i.e., >2 hours) may reduce the risk for renal toxicity, particularly in patients with preexisting renal insufficiency. Severe Hypercalcemia The recommended dose of pamidronate disodium in severe hypercalcemia (corrected serum calcium* >13.5 mg/dL) is 90 mg given as a SINGLE DOSE, intravenous infusion over 2 to 24 hours. Longer infusions (i.e., >2 hours) may reduce the risk for renal toxicity, particularly in patients with preexisting renal insufficiency. * Albumin-corrected serum calcium (CCa, mg/dL) = serum calcium, mg/dL + 0.8 (4.0-serum albumin, g/dL). Retreatment A limited number of patients have received more than one treatment with pamidronate disodium for hypercalcemia. Retreatment with pamidronate disodium, in patients who show complete or partial response initially, may be carried out if serum calcium does not return to normal or remain normal after initial treatment. It is recommended that a minimum of 7 days elapse before retreatment, to allow for full response to the initial dose . The dose and manner of retreatment is identical to that of the initial therapy. Paget’s Disease The recommended dose of pamidronate disodium in patients with moderate to severe Paget’s disease of bone is 30 mg daily, administered as a 4-hour infusion on 3 consecutive days for a total dose of 90 mg. Retreatment A limited number of patients with Paget’s disease have received more than one treatment of pamidronate disodium in clinical trials. When clinically indicated, patients should be retreated at the dose of initial therapy. Osteolytic Bone Lesions of Multiple Myeloma The recommended dose of pamidronate disodium in patients with osteolytic bone lesions of multiple myeloma is 90 mg administered as a 4-hour infusion given on a monthly basis. Patients with marked Bence-Jones proteinuria and dehydration should receive adequate hydration prior to pamidronate disodium infusion. Limited information is available on the use of pamidronate disodium in multiple myeloma patients with a serum creatinine ≥ 3.0 mg/dL. Patients who receive pamidronate disodium should have serum creatinine assessed prior to each treatment. Treatment should be withheld for renal deterioration. In a clinical study, renal deterioration was defined as follows: For patients with normal baseline creatinine, increase of 0.5 mg/dL. For patients with abnormal baseline creatinine, increase of 1.0 mg/dL. In this clinical study, pamidronate disodium treatment was resumed only when the creatinine returned to within 10% of the baseline value. The optimal duration of therapy is not yet known, however, in a study of patients with myeloma, final analysis after 21 months demonstrated overall benefits (see Clinical Trials section). Osteolytic Bone Metastases of Breast Cancer The recommended dose of pamidronate disodium in patients with osteolytic bone metastases is 90 mg administered over a 2-hour infusion given every 3 to 4 weeks. Pamidronate disodium has been frequently used with doxorubicin, fluorouracil, cyclophosphamide, methotrexate, mitoxantrone, vinblastine, dexamethasone, prednisone, melphalan, vincristine, megesterol, and tamoxifen. It has been given less frequently with etoposide, cisplatin, cytarabine, paclitaxel, and aminoglutethimide. Patients who receive pamidronate disodium should have serum creatinine assessed prior to each treatment. Treatment should be withheld for renal deterioration. In a clinical study, renal deterioration was defined as follows: For patients with normal baseline creatinine, increase of 0.5 mg/dL. For patients with abnormal baseline creatinine, increase of 1.0 mg/dL. In this clinical study, pamidronate disodium treatment was resumed only when the creatinine returned to within 10% of the baseline value. The optimal duration of therapy is not known, however, in two breast cancer studies, final analyses performed after 24 months of therapy demonstrated overall benefits (see Clinical Trials section). Calcium and Vitamin D Supplementation In the absence of hypercalcemia, patients with predominantly lytic bone metastases or multiple myeloma, who are at risk of calcium or vitamin D deficiency, and patients with Paget’s disease of the bone, should be given oral calcium and vitamin D supplementation in order to minimize the risk of hypocalcemia. Method of Administr

ADVERSE REACTIONS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Clinical Studies Hypercalcemia of Malignancy Transient mild elevation of temperature by at least 1°C was noted 24 to 48 hours after administration of pamidronate disodium in 34% of patients in clinical trials. In the saline trial, 18% of patients had a temperature elevation of at least 1°C 24 to 48 hours after treatment. Drug-related local soft-tissue symptoms (redness, swelling or induration and pain on palpation) at the site of catheter insertion were most common in patients treated with 90 mg of pamidronate disodium. Symptomatic treatment resulted in rapid resolution in all patients. Rare cases of uveitis, iritis, scleritis, and episcleritis have been reported, including one case of scleritis, and one case of uveitis upon separate rechallenges. Five of 231 patients (2%) who received pamidronate disodium during the four U.S. controlled hypercalcemia clinical studies were reported to have had seizures, 2 of whom had preexisting seizure disorders. None of the seizures were considered to be drug-related by the investigators. However, a possible relationship between the drug and the occurrence of seizures cannot be ruled out. It should be noted that in the saline arm 1 patient (4%) had a seizure. There are no controlled clinical trials comparing the efficacy and safety of 90 mg pamidronate disodium over 24 hours to 2 hours in patients with hypercalcemia of malignancy. However, a comparison of data from separate clinical trials suggests that the overall safety profile in patients who received 90 mg pamidronate disodium over 24 hours is similar to those who received 90 mg pamidronate disodium over 2 hours. The only notable differences observed were an increase in the proportion of patients in the pamidronate disodium 24-hour group who experienced fluid overload and electrolyte/mineral abnormalities. At least 15% of patients treated with pamidronate disodium for hypercalcemia of malignancy also experienced the following adverse events during a clinical trial: General: Fluid overload, generalized pain Cardiovascular: Hypertension Gastrointestinal: Abdominal pain, anorexia, constipation, nausea, vomiting Genitourinary: Urinary tract infection Musculoskeletal: Bone pain Laboratory Abnormality: Anemia, hypokalemia, hypomagnesemia, hypophosphatemia. Many of these adverse experiences may have been related to the underlying disease state. The following table lists the adverse experiences considered to be treatment-related during comparative, controlled U.S. trials. Treatment-Related Adverse Experiences Reported in Three U.S. Controlled Clinical Trials Percent of Patients Pamidronate Disodium Etidronate Disodium Saline 60 mg over 4 hr 60 mg over 24 hr 90 mg over 24 hr 7.5 mg/kg × 3 days n=23 n=73 n=17 n=35 n=23 General Edema 0 1 0 0 0 Fatigue 0 0 12 0 0 Fever 26 19 18 9 0 Fluid overload 0 0 0 6 0 Infusion-site reaction 0 4 18 0 0 Moniliasis 0 0 6 0 0 Rigors 0 0 0 0 4 Gastrointestinal Abdominal pain 0 1 0 0 0 Anorexia 4 1 12 0 0 Constipation 4 0 6 3 0 Diarrhea 0 1 0 0 0 Dyspepsia 4 0 0 0 0 Gastrointestinal hemorrhage 0 0 6 0 0 Nausea 4 0 18 6 0 Stomatitis 0 1 0 3 0 Vomiting 4 0 0 0 0 Respiratory Dyspnea 0 0 0 3 0 Rales 0 0 6 0 0 Rhinitis 0 0 6 0 0 Upper respiratory infection 0 3 0 0 0 CNS Anxiety 0 0 0 0 4 Convulsions 0 0 0 3 0 Insomnia 0 1 0 0 0 Nervousness 0 0 0 0 4 Psychosis 4 0 0 0 0 Somnolence 0 1 6 0 0 Taste perversion 0 0 0 3 0 Cardiovascular Atrial fibrillation 0 0 6 0 4 Atrial flutter 0 1 0 0 0 Cardiac failure 0 1 0 0 0 Hypertension 0 0 6 0 4 Syncope 0 0 6 0 0 Tachycardia 0 0 6 0 4 Endocrine Hypothyroidism 0 0 6 0 0 Hemic and Lymphatic Anemia 0 0 6 0 0 Leukopenia 4 0 0 0 0 Neutropenia 0 1 0 0 0 Thrombocytopenia 0 1 0 0 0 Musculoskeletal Myalgia 0 1 0 0 0 Urogenital Uremia 4 0 0 0 0 Laboratory Abnormalities Hypocalcemia 0 1 12 0 0 Hypokalemia 4 4 18 0 0 Hypomagnesemia 4 10 12 3 4 Hypophosphatemia 0 9 18 3 0 Abnormal liver function 0 0 0 3 0 Paget’s Disease Transient mild elevation of temperature >1°C above pretreatment baseline was noted within 48 hours after completion of treatment in 21% of the patients treated with 90 mg of pamidronate disodium in clinical trials. Drug-related musculoskeletal pain and nervous system symptoms (dizziness, headache, paresthesia, increased sweating) were more common in patients with Paget’s disease treated with 90 mg of pamidronate disodium than in patients with hypercalcemia of malignancy treated with the same dose. Adverse experiences considered to be related to trial drug, which occurred in at least 5% of patients with Paget’s disease treated with 90 mg of pamidronate disodium in two U.S. clinical trials, were fever, nausea, back pain, and bone pain. At least 10% of all pamidronate disodium-treated pa