General
Pamidronate should never be given as a bolus injection since severe local reactions and thrombophlebitis may occur. It should always be diluted and then given as a slow intravenous infusion (see section 4.2).
Do not co-administer pamidronate with other bisphosphonates. If other calcium lowering agents are used in conjunction with pamidronate, significant hypocalcaemia may result.
Pamidronate disodium for injection should not be mixed with calcium-containing intravenous infusions (see section 6.2).
Pamidronate is not recommended during pregnancy.
Patients must be assessed prior to administration of pamidronate to assure that they are appropriately hydrated to maintain urine output. This is especially important for patients receiving diuretic therapy.
Standard hypercalcaemia-related metabolic parameters including serum calcium and phosphate should be monitored following initiation of therapy with pamidronate. Patients who have undergone thyroid surgery may be particularly susceptible to develop hypocalcaemia due to relative hypoparathyroidism.
The safety and efficacy of pamidronate in the treatment of hyperparathyroidism has not been established.
In patients with cardiac disease, especially in the elderly, additional saline overload may precipitate cardiac failure (left ventricular failure or congestive heart failure). Fever (influenza-like symptoms) may also contribute to this deterioration. Patients with anaemia, leukopenia or thrombocytopenia should have regular haematology assessments.
The safety and efficacy of pamidronate in children has not been established. Until further experience is gained, pamidronate is only recommended for use in adult patients.
Patients with tumor-induced hypercalcaemia
Convulsions have been precipitated in some patients with tumour-induced hypercalcaemia due to the electrolyte changes associated with this condition and its effective treatment.
It is essential in the initial treatment of tumour induced hypercalcaemia that intravenous rehydration be instituted to maintain urine output. Patients should be hydrated adequately throughout treatment but overhydration must be avoided.
Renal impairment
Bisphosphonates, including pamidronate disodium have been associated with renal toxicity manifested as deterioration of renal function and potential renal failure. Renal deterioration, progression to renal failure and dialysis have been reported in patients after the initial dose or a single dose of pamidronate disodium. Deterioration of renal function (including renal failure) has been reported following long-term treatment with pamidronate in patients with multiple myeloma; however, underlying disease progression and/or concomitant complications were also present and therefore a causal relationship with pamidronate is unproven. If there is deterioration of renal function during pamidronate therapy, the infusion must be stopped.
Due to the risk of clinically significant deterioration in renal function which may progress to renal failure, single doses of pamidronate should not exceed 90 mg, and the recommended infusion time should be observed (see section 4.2).
Pamidronate disodium is excreted intact primarily via the kidney (see section 5.2), thus the risk of renal adverse reactions may be greater in patients with impaired renal function.
Patients should have standard laboratory (serum creatinine and BUN) and clinical renal function parameters evaluated, prior to each dose of pamidronate, especially those receiving frequent pamidronate infusions over a prolonged period of time, and those with pre-existing renal disease or a predisposition to renal impairment (e.g. patients with multiple myeloma and/or tumour-induced hypercalcaemia). Fluid balance (urine output, daily weights) should also be followed carefully.
Experience with pamidronate in patients with severe renal impairment (serum creatinine: >440 micromol/litre, or 5 mg/dl in TIH patients; 180 micromol/litre, or 2 mg/dl in multiple myeloma patients) is limited. If clinical judgement determines that the potential benefits outweigh the risk in such cases, pamidronate should be used cautiously and renal function carefully monitored.
There is very little experience of the use of pamidronate disodium in patients receiving haemodialysis.
Patients treated with pamidronate for bone metastases or multiple myeloma should have the dose withheld if renal function has deteriorated (see section 4.2).
Pamidronate should not be given with other bisphosphonates because their combined effects have not been investigated.
Hepatic impairment
Pamidronate disodium has not been studied in patients with severe hepatic impairment, therefore no specific recommendations can be given for this patient population (see section 4.2).
Calcium and vitamin D supplementation
In the absence of hypercalcaemia, patients with predominantly lytic bone metastases or multiple myeloma, who are at risk of calcium or vitamin D deficiency (e.g. through malabsorption or lack of exposure to sunlight), and patients with Paget's disease of the bone, should be given oral calcium and vitamin D supplementation, in order to minimise the potential risk of hypocalcaemia.
Osteonecrosis of the jaw
Osteonecrosis of the jaw (ONJ) has been reported in clinical trials and in the post-marketing setting in patients receiving pamidronate.
The start of treatment or of a new course of treatment should be delayed in patients with unhealed open soft tissue lesions in the mouth except in medical emergency situations.
A dental examination with appropriate preventive dentistry and an individual benefit-risk assessment is recommended prior to treatment with bisphosphonates in patients with concomitant risk factors.
The following risk factors should be considered when evaluating an individual's risk of developing ONJ:
• Potency of the bisphosphonate (higher risk for highly potent compounds), route of administration (higher risk for parenteral administration) and cumulative dose of bisphosphonate
• Cancer, co-morbid conditions (e.g. anaemia, coagulopathies, infection), smoking
• Concomitant therapies: chemotherapy, angiogenesis inhibitors (see section 4.5), radiotherapy to neck and head, corticosteroids
• History of dental disease, poor oral hygiene, periodontal disease, invasive dental procedures (e.g. tooth extractions) and poorly fitting dentures
All patients should be encouraged to maintain good oral hygiene, undergo routine dental check-ups, and immediately report any oral symptoms such as dental mobility, pain or swelling, or non-healing of sores or discharge during treatment with pamidronate disodium. While on treatment, invasive dental procedures should be performed only after careful consideration and be avoided in close proximity to pamidronate administration.
For patients who develop osteonecrosis of the jaw while on bisphosphonate therapy, dental surgery may exacerbate the condition. For patients requiring dental procedures, there are no data available to suggest whether discontinuation of bisphosphonate treatment reduces the risk of osteonecrosis of the jaw.
The management plan for the patients who develop ONJ should be set up in close collaboration between the treating physician and a dentist or oral surgeon with expertise in ONJ.
Temporary interruption of pamidronate treatment should be considered until the condition resolves and contributing risk factors are mitigated where possible.
Osteonecrosis of the external auditory canal
Osteonecrosis of the external auditory canal has been reported with bisphosphonates, mainly in association with long-term therapy. Possible risk factors for osteonecrosis of the external auditory canal include steroid use and chemotherapy and/or local risk factors such as infection or trauma. The possibility of osteonecrosis of the external auditory canal should be considered in patients receiving bisphosphonates who present with ear symptoms including chronic ear infections.
Musculoskeletal pain
In post-marketing experience, severe and occasionally incapacitating bone, joint, and/or muscle pain has been reported in patients taking bisphosphonates. However, such reports have been infrequent. This category of drugs includes pamidronate disodium for infusion. The time to onset of symptoms varies from one day to several months after starting the drug. Most patients had relief of symptoms after stopping treatment. A subset had recurrence of symptoms when rechallenged with the same drug or another bisphosphate.
Atypical fractures of the femur
Atypical subtrochanteric and diaphyseal femoral fractures have been reported with bisphosphonate therapy, primarily in patients receiving long-term treatment for osteoporosis. These transverse or short oblique, fractures can occur anywhere along the femur from just below the lesser trochanter to just above the supracondylar flare. These fractures occur after minimal or no trauma and some patients experience thigh or groin pain, often associated with imaging features of stress fractures, weeks to months before presenting with a completed femoral fracture. Fractures are often bilateral; therefore the contralateral femur should be examined in bisphosphonate-treated patients who have sustained a femoral shaft fracture. Poor healing of these fractures has also been reported. Discontinuation of bisphosphonate therapy in patients suspected to have an atypical femur fracture should be considered pending evaluation of the patient, based on an individual benefit risk assessment. During bisphosphonate treatment patients should be advised to report any thigh, hip or groin pain and any patient presenting with such symptoms should be evaluated for an incomplete femur fracture.
Excipient information
This medicine contains less than 1 mmol sodium (23 mg) per vial, that is to say essentially 'sodium-free'.