(DISODIUM PAMIDRONATE (AREDIA®) IN OSTEOPOROSIS)

Available as an injection containing Disodium Pamidronate 15 mg, 30 mg and 90 mg in each vial supplied with diluent for reconbstitution prior to injection. Supplied under the trade name ArediaÒ .

Hypercalcaemia (a high calcium state) occurs when the amount of calcium (a mineral) in the blood is in excess of the normal level. It may be associated with a variety of conditions.

Disodium Pamidronate belongs to the class of drugs known as the Bisphosphonates. Medicines of this type block the mechanism by which bone is broken down (bone wasting) which under normal circumstances works in conjunction with the production of new bone (bone synthesis). These two systems together ensure that a healthy new bone structure is constantly produced in the body. Bone wasting takes place under the influence of specialised cells called osteoclasts and is associated with the release of mineral calcium into blood stream and a tendency for calcium levels rise. Bisphosphonates reduce blood calcium by blocking the action of these cells (osteoclasts).

Disodium Pamidronate is administered by slow intravenous infusion in situations where there is a very high level of calcium in the blood which requires to be reduced rapidly.

Disodium Pamidronate is administered under medical supervision. An intravenous infusion is prepared which must be administered into a large vein (usually in the forearm) over not less than a specified period of time. It must be given over not less than 15 minutes if 15 mg is the dose, or 30 minutes if 30 mg is the dose, or 60 minutes if 60 mg is the dose, or 90 minutes if 90 mg is the dose, and it is often given at even slower rates than this. The actual dose (and frequency with which it is given) varies according to the specific cause of the high calcium state. It is important not to give too much which can result in an inappropriately low blood calcium (hypocalcaemia). The amount of fluid which is given in each infusion varies from no less than 100 ml (about a small cupfull) for a dose as low as 15 mg; 250 ml (about half a pint) for a dose of 60 mg; 500 ml (just under a pint) at the highest dose of 90 mg. The concentration which is given and the time over which it is given are important in order to limit or avoid drug side effects (see below).

What side effects can be expected?

• Disodium Pamidronate is somewhat irritant and during injection it may be associated with skin flushing, flu-like suymptoms, muscle and joint aches and pains, nausea and vomiting, abdominal discomfort and diarrhoea (or constipation) but mainly when given in higher concentrations or at faster rates than those recommended.
  
• Occasionally people complain of confusion, dizziness, lethargy and sleep disturbances following its administration.
  
• Liver and kidney problems are rarely associated with treatment but can be easily checked by a simple blood test. The main problem occurs if it is given to someone who already has a disease affecting their kidneys or liver.
  
• Other uncommon side effects include eye symptoms (redness, visual disturbances), a reduction in the bloods clotting ability and salt and water imbalance.

There are none of any note.

Not applicable. The injection vials are stored in the Pharmacy under refrigeration and removed from the fridge just before use.

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Ó Tayside University Hospitals NHS Trust; 2000; version 1.0

Disclaimer; no liability whatsoever is accepted for information given and all such information, especially with regard to drug usage (UK version provided), must be checked with a person’s health provider.

Available as an injection containing Disodium Pamidronate 15 mg, 30 mg and 90 mg in each vial supplied with diluent for reconbstitution prior to injection. Supplied under the trade name ArediaÒ .

Disodium Pamidronate belongs to the class of drugs known as the Bisphosphonates. Medicines of this type are used to prevent the thinning of the bones which lead to the bone-wasting disease known as osteoporosis and also to treat osteoporosis once it has become established. Osteoporosis is associated with a substantial increase in bone fractures.

The mechanism of action is as follows. Under normal conditions the bone tissue is constantly being broken down and at the same time rebuilt by a process which involves specialised cells in the body. This re-modelling process ensures that a good quality of bone is maintained throughout life. In some situations, however, there may be an imbalance between the cells which break down the bone (the osteoclasts) and those that stimulate the manufacture of new bone (the osteoblasts). When the osteoclasts are relatively more active then reduced bone density and osteoporosis can occur. The Bisphosphonates are able to restore the balance by blocking osteoclasts thereby leading to a reduction in the bone wasting process.

Disodium Pamidronate is administered under medical supervision. An intravenous infusion is prepared which must be administered into a large vein (usually in the forearm) over not less than a specified period of time. It must be given over not less than 15 minutes if 15 mg is the dose, or 30 minutes if 30 mg is the dose, or 60 minutes if 60 mg is the dose, or 90 minutes if 90 mg is the dose, and it is often given at even slower rates than this. The actual dose (and frequency with which it is given) varies according to the specific cause of the high calcium state. It is important not to give too much which can result in an inappropriately low blood calcium (hypocalcaemia). The amount of fluid which is given in each infusion varies from no less than 100 ml (about a small cupfull) for a dose as low as 15 mg; 250 ml (about half a pint) for a dose of 60 mg; 500 ml (just under a pint) at the highest dose of 90 mg. The concentration which is given and the time over which it is given are important in order to limit or avoid drug side effects (see below).

What side effects can be expected?

• Disodium Pamidronate is somewhat irritant and during injection it may be associated with skin flushing, flu-like suymptoms, muscle and joint aches and pains, nausea and vomiting, abdominal discomfort and diarrhoea (or constipation) but mainly when given in higher concentrations or at faster rates than those recommended.
  
• Occasionally people complain of confusion, dizziness, lethargy and sleep disturbances following its administration.
  
• Liver and kidney problems are rarely associated with treatment but can be easily checked by a simple blood test. The main problem occurs if it is given to someone who already has a disease affecting their kidneys or liver.
  
• Other uncommon side effects include eye symptoms (redness, visual disturbances), a reduction in the bloods clotting ability and salt and water imbalance.

There are none of any note.

Not applicable. The injection vials are stored in the Pharmacy under refrigeration and removed from the fridge just before use. 

Top

Ó NHS Tayside; 2006; version 1.0

Disclaimer; no liability whatsoever is accepted for information given and all such information, especially with regard to drug usage (UK version provided), must be checked with a person’s health provider.