Pamidronate Disodium 3 Mg/Ml Concentrate For Solution For Infusion
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Pamidronate Disodium 3mg/ml concentrate for solution for infusion
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each ml of concentrate for solution for infusion contains 3 mg pamidronate disodium equivalent to 2.53 mg of pamidronic acid.
1 vial of 10 ml of sterile concentrate contains 30 mg of pamidronate disodium.
Excipient(s) with known effect: Each vial contains approximately 0.22 mmol (5.06 mg) of sodium (as sodium hydroxide).
For the full list of excipients see section 6.1
3 PHARMACEUTICAL FORM
Concentrate for solution for infusion. Clear colourless solution.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Treatment of conditions associated with increased osteoclast activity:
• Tumour-induced hypercalcaemia
• Osteolytic lesions and bone pain in patients with bone metastases associated with breast cancer or multiple myeloma
• Paget's disease of bone.
4.2 Posology and method of administration Posology:
Adults and older people
Patients with tumour-induced hypercalcaemia
Patients must be adequately rehydrated, using 9mg/ml (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
|
Initial serum calcium |
Recommended total | |
|
(mmol/L) |
(mg %) |
dose (mg) |
|
up to 3.0 |
up to 12.0 |
15 - 30 |
|
3.0 - 3.5 |
12.0 - 14.0 |
30 - 60 |
|
3.5 - 4.0 |
14.0 - 16.0 |
60 - 90 |
|
> 4.0 |
> 16.0 |
90 |
The total dose of Pamidronate Disodium may be administered either in a single infusion or in multiple infusions over 2 to 4 consecutive days. The maximum dose per treatment course is 90 mg for both initial and repeated courses.
A significant decrease in serum calcium is generally observed 24 to 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 treatments increases.
Predominantly lytic bone metastases and multiple myeloma
The recommended dose of pamidronate disodium for the treatment of predominantly lytic bone metastases and multiple myeloma is 90 mg administered as a single infusion every 4 weeks.
In patients with bone metastases who receive chemotherapy at 3-weekly intervals, pamidronate disodium 90 mg may also be given on a 3-weekly schedule.
Patients with Paget’s disease of Bone
The recommended treatment course consists of a total dose of 180mg to 210 mg administered in unit doses of either 30mg once a week for 6 consecutive weeks, or 60mg every other week over 6 weeks. Experience to date suggests that any mild and transient unwanted effects (see Section 4.8 Undesirable effects) tend to occur after the first dose. For this reason if unit doses of 60mg are used it is recommended that treatment be started with an initial dose of 30mg followed by 60mg every other week (i.e. total dose 210mg). Each dose of 30 or 60mg should be diluted in 125 or 250 ml 9mg/ml (0.9% w/v) sodium chloride solution respectively, and the infusion rate should not exceed 60mg/hour (1mg/min). This regimen or increased dose levels according to disease severity, up to a maximum total dose of 360mg (in divided doses of 60mg) can be repeated every 6 months until remission of disease is achieved, and if relapse occurs.
Children and adolescents:
There is no clinical experience with pamidronate disodium in children and adolescents. Therefore until further experience is gained, Pamidronate Disodium is only recommended for use in adult patients.
Method of administration:
Pamidronate Disodium must never be given as a bolus injection (see Section 4.4 Special warnings and special precautions for use).
The concentrate solution of pamidronate disodium should be diluted in a calcium-free infusion solution (9mg/ml (0.9 % w/v) sodium chloride solution or 50mg/ml (5% w/v) glucose solution) and infused slowly.
The infusion rate should never exceed 60mg/hour (1mg/min), and the concentration of Pamidronate Disodium in the infusion solution should not exceed 90mg/250ml. A dose of 90 mg should normally be administered as a 2-hour 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 90 mg in 500 mL over 4 hours (see also Section
4.2 Posology and method of administration “Renal impairment”). In order to minimise local reactions at the infusion site, the cannula should be inserted carefully into a relatively large vein.
For instructions on dilution of the medicinal product before administration, see section 6.6
Special population:
Renal Impairment
Pamidronate Disodium should not be administered to patients with severe renal impairment (creatinine clearance < 30 mL/min) unless in cases of life-threatening 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 “Special warnings and special precautions for use” and Section 5.2 “Pharmacokinetic properties”).
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 0.5mg/dL.
• For patients with abnormal baseline creatinine, increase of 1.0mg/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, active substance accumulation is not expected. Therefore no dose adjustment is necessary in patients with mild to moderate abnormal hepatic function (see Section
5.2 Pharmacokinetic properties “Hepatic impairment”). Clinical data in patients with severe hepatic impairment is not available (see Section 4.4 Special warnings and special precautions for use). Pamidronate should be administered to this patient population with caution.
4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
4.4 Special warnings and precautions for use
Pamidronate Disodium must never be given as a bolus injection, but should always be diluted and given as a slow intravenous infusion (see Section 4.2 Posology and method of administration).
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 hypercalcaemia-related metabolic parameters including serum, 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.
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.
Convulsions have been precipitated in some patients with tumour-induced hypercalcaemia due to the electrolyte changes associated with this condition and its effective treatment.
Patients with anaemia, leukopenia or thrombocytopenia should have regular haematology assessments.
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.
Pamidronate Disodium is excreted intact primarily via the kidney (see Section 5.2 Pharmacokinetic properties), 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 90mg, and the recommended infusion time should be observed (See Section 4.2. Posology and method of administration).
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 disodium 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 disodium.
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. Posology and method of administration).
Pamidronate Disodium should not be administered to patients with severe renal impairment (creatinine clearance < 30 mL/min) unless in cases of life-threatening tumour-induced hypercalcaemia where the benefit outweighs the potential risk. (See section 4.2 Posology and method of administration “Renal impairment”). Because there is only limited pharmacokinetic data with severe renal impairment no dose recommendations for this patient population can be made (See Section 4.2 “Posology and method of administration” and Section 5.2 “Pharmacokinetic properties”). Pamidronate Disodium should not be given with other bisphosphonates because their combined effects have not been investigated.
There is very little experience of the use of pamidronate disodium in patients receiving haemodialysis.
Hepatic impairment
As there are no clinical data available in patients with severe hepatic impairment, no specific recommendations can be given for this patient population (see Sections 4.2 Posology and method of administration and 5.2 Pharmacokinetic properties).
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 in order to minimise the potential risk of hypocalcaemia.
Osteonecrosis of the jaw
Osteonecrosis of the jaw (ONJ) has been reported predominantly in cancer patients treated with bisphosphonates, including pamidronate disodium. Many of these patients were also receiving chemotherapy and corticosteroids. 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).
Patients should maintain good oral hygiene and should have a dental examination with preventive dentistry prior to treatment with bisphosphonates.
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 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.
Musculoskeletal pain
In post-marketing experience, severe and occasionally incapacitating bone, joint, and/or muscle pain has been reported in patients taking bisphosphonates. This category of active substances includes Pamidronate Disodium (pamidronate disodium for infusion). The time to onset of symptoms varied from one day to several months after starting the active substance with the majority occurring within a few days. Most patients had relief or improvement of symptoms after stopping treatment. A subset had recurrence of symptoms when rechallenged with the same active substance or another bisphosphonate.
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
Sodium:
This medicinal product contains approximately 0.22 mmol sodium (5.06 mg) per vial in the form of sodium hydroxide, i.e it is essentially ‘sodium free’.
4.5 Interaction with other medicinal products and other forms of interaction
Pamidronate disodium has been administered concomitantly with commonly used anticancer agents without interactions occurring.
Pamidronate disodium has been used in combination with calcitonin in patients with severe hypercalcaemia, resulting in a synergistic effect producing a more rapid fall in serum calcium.
Caution is warranted when Pamidronate Disodium is used with other potentially nephrotoxic active substances.
In multiple myeloma patients, the risk of renal dysfunction may be increased when Pamidronate Disodium is used in combination with thalidomide.
Since pamidronate binds to bone, it could in theory interfere with bone scintigraphy examinations.
4.6 Fertility, Pregnancy and lactation Fertility
There is no relevant data available.
Woman of child-bearing potential
Woman of child-bearing potential must use highly effective contraceptive measures during treatment.
Pregnancy
There are no adequate data from the use of pamidronate in pregnant women. There is no unequivocal evidence for teratogenicity in animal studies but administration of pamidronate during the whole period of gestation can cause bone mineralisation disorder in animal offspring (see section 5.3). Pamidronate may pose a risk to the foetus/newborn child through its pharmacological action on calcium homeostasis.
The potential risk for humans is unknown. Therefore, pamidronate should not be used during pregnancy except in cases of life-threatening hypercalcaemia.
Breast-feeding
Very limited experience indicates maternal milk levels of pamidronate under the limit of detection. Moreover the oral bioavalibility 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.
4.7 Effects on ability to drive and use machines
Patients should be warned that 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.
4.8 Undesirable effects
Adverse reactions to Pamidronate Disodium are usually mild and transient. The most common adverse reactions are asymptomatic hypocalcaemia 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.
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
|
Infections and in |
'estations |
|
Very rare: |
reactivation of Herpes simplex, reactivation of Herpes zoster. |
|
Blood and lymphatic system disorders | |
|
Common: |
anaemia, thrombocytopenia, lymphocytopenia. |
|
Very rare: |
leukopenia. |
|
Immune system disorders | |
|
Uncommon: |
allergic reactions including anaphylactoid reactions, bronchospasm/dyspnoea, Quincke's (angioneurotic) oedema. |
|
Very rare: |
anaphylactic shock |
|
Metabolism and nutrition disorders | |
|
Very common: |
hypocalcaemia, hypophosphataemia. |
|
Common: |
hypokalaemia, hypomagnesaemia. |
|
Very rare: |
hyperkalaemia, hypernatraemia. |
|
Nervous system disorders | |
|
Common: |
symptomatic hypocalcaemia (tetany, paraesthesia), headache, insomnia, somnolence. |
|
Uncommon: |
seizures, lethargy, agitation, dizziness. |
|
Very rare: |
confusion, visual hallucinations. |
|
Eye disorders | |
|
Common: |
conjunctivitis. |
|
Uncommon: |
uveitis (iritis, iridocyclitis). |
|
Very rare: |
scleritis, episcleritis, xanthopsia. |
|
Not known |
Orbital inflammation |
|
Cardiac disorders | |
|
Common |
atrial fibrillation |
|
Very rare: |
left ventricular failure (dyspnoea, pulmonary oedema), congestive heart failure (oedema) due to fluid overload. |
|
Respiratory, thoracic and mediastinal disorders | |
|
Very rare: |
acute respiratory distress syndrome, interstitial lung disease. |
|
Vascular disorders | |
|
Common |
hypertension |
|
Uncommon |
hypotention |
|
Gastrointestinal disorders | |
|
Common: |
nausea, vomiting, anorexia, abdominal pain, diarrhoea, constipation, gastritis. |
|
Uncommon: |
dyspepsia. |
|
Skin and subcutaneous disorders | |
|
Common: |
rash |
|
Uncommon: |
pruritus. |
|
Musculoskeletal and connective tissue disorders | |
|
Common: |
transient bone pain, arthralgia, myalgia, generalised pain. |
|
Uncommon: |
muscle cramps, osteonecrosis. |
|
Not known: |
severe and occasionally incapacitating bone, joint, and/or muscle pain, osteonecrosis of the jaw, atypical subtrochanteric and diaphyseal femoral fractures. |
|
Renal and urinary disorders | |
|
Uncommon: |
acute renal failure. |
|
Rare: |
focal segmental glomerulosclerosis including the collapsing variant, nephrotic syndrome. |
|
Very rare: |
deterioration of pre-existing renal disease, haematuria, renal tubular disorder. |
|
Not known: |
tubulointerstitial nephritis, glomerulonephropathy. |
|
General disorders and administration site conditions | |
|
Very common: |
fever and influenza-like symptoms sometimes accompanied by malaise, rigor, fatigue and flushes |
|
Common: |
reactions at the infusion site: pain, redness, swelling, induration, phlebitis, thrombophlebitis |
|
Investigations | |
|
Very Common: |
increase in serum creatinine. |
|
Uncommon: |
abnormal liver function tests, increase in serum urea. |
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 (5 mg) had an increased risk of atrial fibrillation serious adverse events compared to placebo (1.3% compared to 0.6%). Isolated instances of higher incidence of atrial fibrillation have also been reported in a few studies with other bisphosphonates. The mechanism of this increased incidence of atrial fibrillation in isolated studies with some biphosphonates, including pamidronate disodium, 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 disodium.
Osteonecrosis of the jaw: Cases of osteonecrosis (primarily of the jaw) have been reported predominantly in cancer patients treated with bisphosphonates including pamidronate disodium Many of these patients 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 Special warnings and precautions for use).
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.
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.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Pharmacotherapeutic group: Medicinal products affecting bone structure and mineralization, Bisphosphonates
ATC code: M05B A 03
Pamidronate disodium, the active substance of 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 active substance to the bone mineral.
Pamidronate suppresses the accession of osteoclast precursors onto the bone. However, the local and direct antiresorptive effect of bone-bound bisphosphonate 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 rise rapidly after the start of an infusion and fall rapidly when the infusion is stopped. The apparent half-life 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 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 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. 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, 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. 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).
Special population 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 disodium 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. Active substance levels were not detectable in patients by 12-36 hours after medicinal product infusion. Because Pamidronate Disodium is administered on a monthly basis, active substance accumulation is not expected. No changes in Pamidronate Disodium dosing regimen are recommended for patients with mild to moderate abnormal hepatic function (see Section 4.2 Posology and method of administration).
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 Section 4.2 “Posology and method of administration” and Section 4.4 “Special warnings and special precautions for use”).
5.3 Preclinical safety data
In pregnant rats, pamidronate has been shown to cross the placenta and accumulate in foetal bone in a manner similar to that observed in adult animals. When administered during the whole period of gestation in animals, pamidronate can cause bone mineralisation disorder especially of long bones resulting in angular distortion. Pamidronate disodium 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 (approximately equivalent to 1.2 mg/kg intravenously) 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 disodium 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 disodium doses (1-6 mg/kg/day) interfered (pre-partum distress and fetotoxicity) with normal parturition in the rat. These effects: foetal developmental abnormalities, prolonged parturition and reduced survival rate of pups were probably caused by a decrease in maternal serum calcium levels.
Only low intravenous doses have been investigated in pregnant rabbits, because of maternal toxicity, but the highest dose used (1.5 mg/kg/day) was associated with an increased resorption rate and reduced ossification. However there was no evidence for teratogenicity.
The toxicity of pamidronate is characterised by direct (cytotoxic) effects on organs with a copious blood supply such as the stomach, lungs and kidneys. In animal studies with intravenous administration, renal tubular lesions were the prominent and consistent untoward effects of treatment.
Carcinogenesis and mutagenesis
Pamidronate disodium by daily oral administration was not carcinogenic in an 80 week or a 104 week study in mice.
Pamidronate disodium 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
Sodium hydroxide Phosphoric acid Water for injections
6.2 Incompatibilities
Pamidronate will form complexes with divalent cations and should not be mixed with calcium-containing solutions.
Shelf life
6.3
Shelf life of unopened vial: 3 years.
In use: Chemical and physical stability after dilution of Pamidronate disodium 3 mg/ml concentrate for solution for infusion with sodium chloride 9mg/ml (0.9%) solution for injection , sodium chloride 4.5mg/ml (0.45%) solution for injection and glucose 50mg/ml (5%) solution for injection at 25°C is stable for 24 hours.
After first opening or following dilution, from a microbiological point of view, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are responsibility of the user and would not normally be longer than 24 hours at 25° C, unless opening and dilution has taken place in controlled and validated aseptic conditions.
6.4 Special precautions for storage
This medicinal product does not require any special storage conditions.
For storage conditions after dilution of the medicinal product, see section 6.3.
6.5 Nature and contents of container
Type I tubular vial plugged with grey bromobutyl rubber stopper and sealed with flip off aluminium seal.
Pack sizes:
1 vial of 10 ml
2 vials of 10 ml 4 vials of 10 ml
Not all pack sizes may be marketed.
6.6 Special precautions for disposal
Must be diluted with calcium-free infusion solution (9mg/ml (0.9% w/v) sodium chloride, 4.5mg/ml (0.45% w/v) sodium chloride or 50mg/ml (5% w/v) glucose solution) before administration.
The concentration of pamidronate disodium in the infusion solution should not exceed 90mg/250ml.
Discard any unused solution immediately after initial use.
7 MARKETING AUTHORISATION HOLDER
Generics [UK] Limited t/a Mylan
Station Close
Potters Bar
Hertfordshire
EN6 1TL
United Kingdom
8 MARKETING AUTHORISATION NUMBER(S)
PL 04569/1548
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
10/12/2013
10 DATE OF REVISION OF THE TEXT
28/05/2015