PAMIDRONATE DISODIUM 9 MG / ML CONCENTRATE FOR SOLUTION FOR INFUSION - Summary of medicine characteristics

Pamidronate disodium 9 mg/ ml concentrate for solution for infusion.

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Each ml of concentrate for solution for infusion contains 11.90mg/ml of pamidronate disodium pentahydrate, which is equivalent to 9mg/ml of pamidronate disodium anhydrous.

1 vial of 10 ml of concentrate for solution for infusion contains 90 mg of pamidronate disodium.

For the full list of excipients, see section 6.1.

Concentrate for solution for infusion.

Pamidronate disodium 9 mg/ ml is a clear colourless solution in flint glass vial.

4.1 Therapeutic indications

Treatment of conditions associated with increased osteoclast activity

The treatment of tumour-induced hypercalcaemia.

Osteolytic lesions and bone pain in patients with bone metastases associated with breast cancer and multiple myeloma

Paget's disease of bone.

4.2 Posology and method of administration

Pamidronate disodium must never be given as a bolus injection (see section 4.4). The concentrate pamidronate disodium in ampules should be diluted in a calcium-free infusion solution (0.9 % w/v sodium chloride solution or 5% w/v glucose solution- see section 6.2) and infused slowly.

For information concerning compatibility with infusion solutions, refer to section 6.6.

The infusion rate should never exceed 60 mg/hour (1 mg/min), and the concentration of pamidronate disodium in the infusion solution should not exceed 60 mg/250 ml. A dose of 60 mg should normally be administered as a 2-hours infusion in 250 mL infusion solution. In patients with established or suspected renal impairment (e.g. those with tumour-induced hypercalcaemia or multiple myeloma) it is recommended that the infusion rate does not exceed 20 mg/hour (see also “Renal Impairment”). In order to minimise local reactions at the infusion site, the cannula should be inserted carefully into a relatively large vein.

Adults and elderly

Tumour-induced hypercalcaemia

Patients must be adequately rehydrated, using 0.9% w/v sodium chloride solution, prior to and during administration of pamidronate disodium.

The total dose of pamidronate disodium to be used for a treatment course depends on the patient's initial serum calcium levels. The following guidelines are derived from clinical data on uncorrected calcium values. However, doses within the ranges given are also applicable for calcium values corrected for serum protein or albumin in rehydrated patients.

Table 1 Recommended doses according to serum calcium levels

The total dose of pamidronate disodium may be administered either in a single infusion or in multiple infusions over 2–4 consecutive days. The maximum dose per treatment course is 90 mg for both initial and repeat courses.

A significant decrease in serum calcium is generally observed 24–48 hours after administration of pamidronate disodium, and normalisation is usually achieved within 3 to 7 days. If normocalcaemia is not achieved within this time, a further dose may be given. The duration of the response may vary from patient to patient, and treatment can be repeated whenever hypercalcaemia recurs. Clinical experience to date suggests that pamidronate disodium may become less effective as the number of treatment increases.

Osteolytic lesions and bone , pain in multiple myeloma

The recommended dose is 90 mg administered as single infusion every 4 weeks.

Osteolytic lesions and bone pain in bone metastases associated with breast cancer

The recommended dose is 90 mg every 3 weeks. This dose may also be administered at 3 weekly intervals to coincide with chemotherapy if desired.

Paget's disease of bone

The recommended treatment course consists of a total dose of 180 to 210 mg administered in unit doses of either 30 mg once a week for 6 consecutive weeks, or 60 mg every other week over 6 weeks. Experience to date suggests that any mild and transient unwanted effects (see section 4.8) tend to occur after the first dose. For this reason if unit doses of 60 mg are used it is recommended that treatment be started with an initial additional dose of 30 mg (i.e. total dose 210 mg). Each dose of 30 or 60 mg should be diluted in 125 or 250 ml 0.9 % w/v Sodium Chloride Intravenous Infusion BP respectively, and the infusion rate should not exceed 60 mg/hour (1 mg/min). This regimen or increased dose levels according to disease severity, up to a maximum total dose of 360 mg (in divided doses of 60 mg) can be repeated every 6 months until remission of disease is achieved, and if relapse occurs.

Renal impairment

Pamidronate disodium should not be administered to patients with severe renal impairment (creatinine clearance < 30 mL/min) unless in cases of lifethreatening tumour-induced hypercalcaemia where the benefit outweighs the potential risk. Because there is only limited clinical experience in patients with severe renal impairment no dose recommendations for this patient population can be made (see section 4.4 and 5.2).

As with other i.v. bisphosphonates, renal monitoring is recommended, for instance, measurement of serum creatinine prior to each dose of pamidronate disodium. In patients receiving pamidronate disodium for bone metastases or multiple myeloma who show evidence of deterioration in renal function, pamidronate disodium treatment should be withheld until renal function returns to within 10% of the baseline value. This recommendation is based on a clinical study, in which 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.

A pharmacokinetic study conducted in patients with cancer and normal or impaired renal function indicates that the dose adjustment is not necessary in mild (creatinine clearance 61–90 mL/min) to moderate renal impairment (creatinine clearance 30–60 mL/min). In such patients, the infusion rate should not exceed 90 mg/4h (approximately 20–22 mg/h).

Hepatic impairment

Although patients with hepatic impairment exhibited higher mean AUC and Cmax values compared to patients with normal hepatic function, this is not perceived being clinically relevant. As pamidronate is still rapidly cleared from the plasma almost entirely into the bone and as is administered on a monthly basis for chronic treatment, drug accumulation is not expected. Therefore no dose adjustment is necessary in patients with mild to moderate abnormal hepatic function (see section 5.2). Clinical data in patients with severe hepatic impairment is not available (see section 4.4). Pamidronate should be administered to this patient population with caution.

Paediatric population

There is no clinical experience with pamidronate disodium in children. Therefore until further experience is gained, pamidronate disodium is only recommended for use in adult patients.

4.3 Contraindications

Pamidronate disodium is contraindicated in:

patients with known hypersensitivity to pamidronate or to other bisphosphonates, or to any of the excipients listed in section 6.1,

pregnancy,

breast feeding women.

4.4 Special warnings and precautions for use

General

Pamidronate must never be given as a bolus injection, since severe local reactions and thrombophlebitis may occur but should always be diluted and 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.

Patients must be assessed prior to administration of pamidronate disodium to assure that they are appropriately hydrated. This is especially important for patients receiving diuretic therapy.

Standard hypocalcaemia-related metabolic parameters including serum electrolyte, calcium and phosphate should be monitored following initiation of therapy with pamidronate disodium. Patients who have undergone thyroid surgery may be particularly susceptible to developing hypocalcaemia due to relative hypoparathyroidism. The safety and efficacy of pamidronate in the treatment of hyperparathyroidism has not been established.

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.

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.

Convulsions have been precipitated in some patients with tumour-induced hypercalcaemia due to the electrolyte changes associated with this condition and its effective treatment.

Pamidronate disodium should be given under the supervision of a physician with the facilities to monitor the clinical and biochemical effects.

Special population

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 also been reported following long-term treatment with pamidronate disodium 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.

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.

Due to the risk of clinically significant deterioration in renal function which may progress to renal failure, single doses of pamidronate disodium should not exceed 90 mg, and the recommended infusion time should be observed (see section 4.2).

As with other i.v. bisphosphonates renal monitoring is recommended, for instance, measurement of serum creatinine prior to each dose of pamidronate disodium.

Patients receiving frequent infusions of pamidronate over a prolonged period of time, especially those with pre-existing renal disease or a predisposition to renal impairment (e.g. patients with multiple myeloma and/or tumour-induced hypercalcaemia), should have evaluations of standard laboratory and clinical parameters of renal function prior to each dose of pamidronate. Fluid balance (urine output, daily weights) should also be followed carefully.

Patients treated with pamidronate disodium for bone metastases or multiple myeloma should have the dose withheld if renal function has deteriorated (see section 4.2).

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.

Hepatic impairment

As pamidronate disodium has not been studied and no clinical data available in patients with severe hepatic impairment, therefore no specific recommendations can be given for this patient population (see sections 4.2 and 5.2).

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 take oral calcium and vitamin D supplementation during pamidronate disodium therapy to minimise the potential risk of hypocalcaemia.

Osteonecrosis of the jaw

Osteonecrosis of the jaw (ONJ) has been reported uncommonly in clinical trials and in the post-marketing setting in cancer patients treated with bisphosphonates, including pamidronate. Many of these patients were also receiving chemotherapy and corticosteroids. The majority of reported cases have been associated with dental procedures such as tooth extraction. Many had signs of local infection including osteomyelitis.

Post-marketing experience and the literature suggest a greater frequency of reports of ONJ based on tumour type (advanced breast cancer, multiple myeloma), and dental status (dental extraction, periodontal disease, local trauma including poorly fitting dentures).

Cancer patients should maintain good oral hygiene and should have a dental examination with preventive dentistry prior to treatment with bisphosphonates.

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 should be considered prior to treatment with bisphosphonates in patients with concomitant risk factors (e.g. cancer, chemotherapy, corticosteroids, poor oral hygiene).

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, these patients should avoid invasive dental procedures if possible. For patients who develop osteonecrosis of the jaw while on bisphosphonate therapy, dental surgery may exacerbate the condition. 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. Clinical judgement of the treating physician should guide the management plan of each patient based on individual benefit/risk assessment.

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.

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.

4.5 Interaction with other medicinal products and other forms of interaction

Other biphosphonates

Pamidronate disodium should not be co-administered with other bisphosphonates because their combined effects have not been investigated.

Anticancer agents

Pamidronate disodium has been administered concomitantly with commonly used anti-cancer agents (including aminoglutethimide, cisplatin, corticosteroids, cyclophosphamide, cytarabine, doxorubicin, etoposide, fluorouracil, megestrol, melphalan, methotrexate, mitoxantrone, paclitaxel, tamoxifen, vinblastine and vincristine) without significant interactions occurring.

Calcitonin and mithramycin

Pamidronate has been used in combination with both calcitonin and mithramycin in patients with severe hypercalcaemia, resulting in a synergistic effect producing a more rapid fall in serum calcium.

Nephrotoxic drugs

Caution is warranted when pamidronate disodium is used with other potentially nephrotoxic drugs.

Thalidomide

In multiple myeloma patients, the risk of renal dysfunction may be increased when pamidronate disodium is used in combination with thalidomide.

Bone scintigraphy examinations

Since pamidronate binds to bone, it could in theory interfere with bone scintigraphy examinations.

Anti-angiogenic medicinal products

Caution is advised when pamidronate is administered with anti-angiogenic medicinal products, as an increase in the incidence of ONJ has been observed in patients treated concomitantly with these medicinal products.

4.6 Fertility, Pregnancy and lactation

Fertility

There are no data available.

Women of child-bearing potential

Women of child-bearing potential must use highly effective contraception during treatment.

Pregnancy

In animal experiments, pamidronate showed no teratogenic potential and did not affect general reproductive performance or fertility. There are no adequate data from the use of pamidronate in pregnant women. Studies in animals have shown reproductive toxicity (see section 5.3). Dystocia was observed in the rats. There is no unequivocal evidence for teratogenicity in animal studies. Pamidronate may pose a risk to the foetus/newborn child through its pharmacological action on calcium homeostasis. When administered during the entire period of gestation in animals, pamidronate can cause bone mineralisation defects, especially in long bones, resulting in angular distortion.

The potential risk for humans is unknown, and there is insufficient clinical experience to support the use of pamidronate disodium in pregnant women. It is not known if pamidronate crosses the human placenta. Therefore, pamidronate should not be administered during pregnancy at any stage except in case of life-threatening hypercalcaemia cannot be controlled by any other means (see section 4.3).

Breast-feeding

It is not known whether pamidronate disodium is excreted into human milk. Very limited experience indicates maternal milk levels of pamidronate under the limit of detection. A study in lactating rats has shown that pamidronate disodium will pass into the milk. Moreover the oral bioavailability is poor so the total absorption of pamidronate by a breastfed infant is not likely. However due to extremely limited experience and the potential of pamidronate to have an important impact on bone mineralisation breastfeeding during the therapy is not recommended. Study in lactating rats has shown that pamidronate will pass into the milk. Mothers treated with pamidronate disodium should therefore not breast-feed their infants (see section 4.3).

4.7 Effects on ability to drive and use machines

Patients should be warned that in rare cases somnolence and/or dizziness may occur following pamidronate disodium infusion, in which case they should not drive, operate potentially dangerous machinery, or engage in other activities that may be hazardous because of decreased alertness. This effect rarely lasts more than 24 hours. Outpatients who have received a pamidronate infusion should not drive themselves home.

4.8 Undesirable effects

Adverse reactions to pamidronate disodium are usually mild and transient. The most common adverse reactions are asymptomatic hypocalcaemia with influenza-like symptoms and fever (an increase in body temperature of 1–2°C), typically occurring within the first 48 hours of infusion. Fever usually resolves spontaneously and does not require treatment. Acute “influenza-like” reactions usually occur only with the first pamidronate infusion. Symptomatic hypocalcaemia is uncommon. Local soft tissue inflammation at the infusion site also occurs, especially at the highest dose.

Adverse reactions (Table 2) are ranked under headings of frequency, the most frequent first, using the following convention: Frequency estimate: very common (>1/10), common (>1/100, <1/10), uncommon (>1/1,000, <1/100), rare (>1/10,000, <1/1,000), very rare (<1/10,000) including isolated reports, not known (cannot be estimated from the available data).

The following adverse drug reactions were reported from clinical studies and from postmarketing experience with pamidronate. Because the post marketing reports are from a population of uncertain size and are subject to confounding factors, it is not possible to reliably estimate their frequency (which is therefore categorised as not known) or establish a causal relationship to drug exposure.

Table 2 Adverse drug reactions

1 Reports of these events are generally associated with high dosage (exceeding the recommended dosage or reduced dosing intervals) and/or long-term use

Description of selected adverse drug reactions (class label)

Atrial fibrillation: When the effects of zoledronic acid (4 mg) and Pamidronate (90 mg) were compared in one clinical trial, the number of atrial fibrillation adverse events was higher in the pamidronate group (12/556, 2.2%) than in the zoledronic acid group (3/563, 0.5%). Previously, it has been observed in a clinical trial, investigating patients with postmenopausal osteoporosis, that zoledronic acid treated patients (4 mg) had an increased risk of atrial fibrillation serious adverse events compared to placebo (1.3% compared to 0.6%). The mechanism of this increased incidence of atrial fibrillation in isolated studies with some bisphosphonates, including pamidronate, is unknown.

Musculoskeletal and connective tissue disorders: Cases of atypical subtrochanteric and diaphyseal femoral fractures have been reported with bisphosphonates (class adverse reaction), including pamidronate.

Postmarketing experience

Osteonecrosis of the jaw: The following adverse reactions have been reported during postapproval use of pamidronate.

Cases of osteonecrosis (primarily of the jaw) have been reported predominantly in cancer patients treated with bisphosphonates including pamidronate disodium (see section 4.4). Many of these patients were also receiving chemotherapy and corticosteroids and had signs of local infection including osteomyelitis and the majority of the reports refer to cancer patients following tooth extractions or other dental surgeries. Osteonecrosis of the jaw has multiple well documented risk factors including a diagnosis of cancer, concomitant therapies (e.g. chemotherapy, radiotherapy, corticosteroids) and co-morbid conditions (e.g. anaemia, coagulopathies, infection, pre-existing oral disease). Although causality has not been determined, it is prudent to avoid dental surgery as recovery may be prolonged (see section 4.4). Data suggest a greater frequency of reports of ONJ based on tumour type (advanced breast cancer, multiple myeloma).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9 Overdose

Patients who have received doses higher than those recommended should be carefully monitored. In the event of clinically significant hypocalcaemia with paraesthesia, tetany and hypotension, reversal may be achieved with an infusion of calcium gluconate. Acute hypocalcaemia is not expected to occur with pamidronate since plasma calcium levels fall progressively for several days after treatment.

5 PHARMACOLOGICAL PROPERTIES

5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Bisphosphonates

ATC code: M05BA03

Mechanism of action

Pamidronate disodium, is a potent inhibitor of osteoclastic bone resorption. It binds strongly to hydroxyapatite crystals and inhibits the formation and dissolution of these crystals in vitro. Inhibition of osteoclastic bone resorption in vivo may be at least partly due to binding of the drug to the bone mineral.

Pamidronate disodium suppresses the accession of osteoclast precursors onto the bone. However, the local and direct antiresorptive effect of bone-bound biphosphonate appears to be the predominant mode of action in vitro and in vivo.

Experimental studies have demonstrated that pamidronate inhibits tumour-induced osteolysis when given prior to or at the time of inoculation or transplantation with tumour cells. Biochemical changes reflecting the inhibitory effect of pamidronate disodium on tumour-induced hypercalcaemia, are characterised by a decrease in serum calcium and phosphate and secondarily by decreases in urinary excretion of calcium, phosphate and hydroxyproline.

Hypercalcaemia can lead to a depletion in the volume of extracellular fluid and a reduction in the glomerular filtration rate (GFR). By controlling hypercalcaemia, pamidronate disodium improves GFR and lowers elevated serum creatinine levels in most patients.

Clinical trials in patients with breast cancer and predominantly lytic bone metastases or with multiple myeloma showed that pamidronate disodium prevented or delayed skeletal-related events (hypercalcaemia, fractures, radiation therapy, surgery to bone, spinal cord compression) and decreased bone pain.

Paget's disease of bone, which is characterised by local areas of increased bone resorption and formation with qualitative changes in bone remodelling, responds well to treatment with pamidronate disodium. Clinical and biochemical remission of the disease has been demonstrated by bone scintigraphy, decreases in urinary hydroxyproline and serum alkaline phosphatase, and by symptomatic improvement.

5.2 Pharmacokinetic properties

General characteristics

Pamidronate has a strong affinity for calcified tissues, and total elimination of pamidronate from the body is not observed within the time-frame of experimental studies. Calcified tissues are therefore regarded as site of “apparent elimination”.

Absorption

Pamidronate disodium is given by intravenous infusion. By definition, absorption is complete at the end of the infusion.

Distribution

Plasma concentrations of pamidronate disodium rise rapidly after the start of an infusion and fall rapidly when the infusion is stopped. The apparent halflife in plasma is about 0.8 hours. Apparent steady-state concentrations are therefore achieved with infusions of more than about 2–3 hours’ duration. Peak plasma pamidronate disodium concentrations of about 10 nmol/ml are achieved after an intravenous infusion of 60 mg given over 1 hour.

In animals and in man, a similar percentage of the dose is retained in the body after each dose of pamidronate disodium. Thus the accumulation of pamidronate in bone is not capacity-limited, and is dependent solely on the total cumulative dose administered.

The percentage of circulating pamidronate bound to plasma proteins is relatively low (about 54 %) and increases when calcium concentrations are pathologically elevated.

Elimination

Pamidronate disodium does not appear to be eliminated by biotransformation and it is almost exclusively eliminated by renal excretion. After an intravenous infusion, about 20–55 % of the dose is recovered in the urine within 72 hours as unchanged pamidronate disodium. Within the time-frame of experimental studies the remaining fraction of the dose is retained in the body. The percentage of the dose retained in the body is independent of both the dose (range 15–180 mg) and the infusion rate (range 1.25–60 mg/h). From the urinary elimination of pamidronate disodium, two decay phases with apparent half-lives of about 1.6 and 27 hours, can be observed. The apparent total plasma clearance is about 180mL/min and the apparent renal clearance is about 54 ml/min, and there is a tendency for the renal clearance to correlate with creatinine clearance.

Characteristics in patients

Hepatic and metabolic clearance of pamidronate are insignificant. Pamidronate disodium thus displays little potential for drug-drug interactions both at the metabolic level and at the level of protein binding (see above).

Hepatic impairment

The pharmacokinetics of pamidronate were studied in male cancer patients at risk for bone metastases with normal hepatic function (n=6) and mild to moderate hepatic dysfunction (n=9). Each patient received a single 90mg dose of Pamidronate infused over 4 hours. There was a statistically significant difference in the pharmacokinetics between patients with normal and impaired hepatic function. Patients with hepatic impairment exhibited higher mean AUC (39.7%) and Cmax (28.6%) values. The difference was not considered clinically relevant. The mean ratio based on log transformed parameters of impaired versus normal patients was 1.38 (90% C.I. 1.12 – 1.70, P=0.02) for AUC and 1.23 (90% C.I. 0.89 – 1.70, P=0.27) for Cmax. Nevertheless, pamidronate was still rapidly cleared from the plasma. Drug levels were not detectable in patients by 12–36 hours after drug infusion. Because pamidronate is administered on a monthly basis, drug accumulation is not expected. No changes in pamidronate dosing regimen are recommended for patients with mild to moderate abnormal hepatic dysfunction (see section 4.2).

Renal impairment

A pharmacokinetic study conducted in patients with cancer showed no differences in plasma AUC of pamidronate between patients with normal renal function and patients with mild to moderate renal impairment. In patients with severe renal impairment (creatinine clearance <30mL/min), the AUC of pamidronate was approximately 3 times higher than in patients with normal renal function (creatinine clearance >90mL/min). Because there is only limited pharmacokinetic data with severe renal impairment no dose recommendations for this patient population can be made (see sections 4.2 and 4.4).

5.3 Preclinical safety data

In pregnant rats, pamidronate has been shown to cross the placental barrier and accumulate in foetal bone in a manner similar to that observed in adult animals. Pamidronate has been shown to increase the length of gestation and parturition in rats resulting in an increasing pup mortality when given orally at daily doses of 60 mg/kg and above (0.7 times the highest recommended human dose for a single intravenous infusion). There was no unequivocal evidence for teratogenicity in studies with intravenous administration of pamidronate to pregnant rats, although high doses (12 and 15 mg/kg/day) were associated with maternal toxicity and foetal developmental abnormalities (foetal oedema and shortened bones) and doses of 6 mg/kg and above with reduced ossification. Lower intravenous pamidronate doses (1–6 mg/kg/day) interfered (pre-partum distress and fetotoxicity) with normal parturition in the rat, and this may be associated with maternal hypocalcaemia. Only low intravenous doses have been investigated in pregnant rabbits, because of maternal toxicity, and the highest dose used (1.5 mg/kg/day) was associated with an increased resorption rate and reduced ossification, but there was no evidence for teratogenicity.

Acute toxicity

The toxicity of pamidronate is characterised by direct (cytotoxic) effects on organs with a copious blood supply, particularly the stomach, lungs and kidneys following i.v. exposure. The compound is not mutagenic and does not appear to have carcinogenic potential.

Reproductive toxicity

Studies in rats and rabbits determined that pamidronate disodium produces maternal toxicity and embryo/foetal effects when administered at doses of 0.6 to 8.3 times the highest recommended human dose for a single intravenous infusion. The effects include protracted parturition leading to dystocia, and shortened long bones in the foetus. Animal data suggest that uptake of bisphosphonates into foetal bone is greater than into maternal bone. A study in lactating rats has shown that pamidronate will pass into the milk.

Mutagenicity and carcinogenic potential

There is a lack of long-term toxicology data from animal studies, with intravenous administration.

In a 104 week carcinogenicity study of daily oral administration to rats, there was a positive dose response relationship for benign phaeochromocytoma in male animals. Although this condition was also observed in female animals, the incidence was not statistically significant. When the dosage calculations were adjusted to account for the limited oral bioavailability of pamidronate in rats, the lowest daily dose associated with adrenal phaeochromocytoma was similar to the intended clinical dose in humans. In a second rat carcinogenicity study, adrenal phaeochromocytomas were not reported at doses similar to the intended clinical dose in humans. Pamidronate by daily oral administration was not carcinogenic in an 80 week or a 104 week study in mice.

Pamidronate showed no genotoxic activity in a standard battery of assays for gene mutations and chromosomal damage.

6 PHARMACEUTICAL PARTICULARS

6.1 List of excipients

Mannitol, Phosphoric acid, Water for Injection.

6.2 Incompati­bilities

Pamidronate must not be mixed with calcium-containing solution such as Ringer's solution.

To avoid potential incompatibilities, Pamidronate is to be diluted with 0.9% w/v sodium chloride solution or 5% w/v glucose solution.

6.3 Shelf life

2 years.

6.4 Special precautions for storage

Following dilution in 0.9% sodium chloride and 5% glucose infusion solutions, chemical and physical in-use stability has been demonstrated for 24 hours at temperatures not exceeding 25°C.

If not used immediately, the duration and conditions of storage prior to use are the care provider's res­ponsibility. The total time between dilution and storage in a refrigerator at 2 to 8°C and end of administration must not exceed 24 hours.

Prior to first use: Store below 25°C. Store in the original package in order to protect from light.

6.5 Nature and contents of container

10 ml Type I moulded flint glass vial with butyl rubber stopper and dark green coloured flip-off, tear-off aluminium seals in packs of 1 vial.

6.6 Special precautions for disposal

Must be diluted prior to administration.

The concentration of pamidronate disodium in the infusion solution should not exceed 60 mg/ 250 ml.

Do not use solution if particles are present.

Any portion of the contents remaining after use should be discarded.

7 MARKETING AUTHORISATION HOLDER

8   MARKETING AUTHORISATION NUMBER(S)

9 DATE OF FIRST AUTHORISATION/RENEWAL OF THEAUTHORISATION

10/06/2010