Consumer medicine information

DBL Potassium Dihydrogen Phosphate Concentrated Injection

Potassium phosphate, monobasic

BRAND INFORMATION

Brand name

DBL Potassium Dihydrogen Phosphate Concentrated Injection

Active ingredient

Potassium phosphate, monobasic

Schedule

Unscheduled

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using DBL Potassium Dihydrogen Phosphate Concentrated Injection.

What is in this leaflet

This leaflet answers some common questions about DBL™ Potassium Dihydrogen Phosphate Concentrated Injection. It does not contain all the available information. It does not take the place of talking to your doctor and pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you being given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection against the benefits this medicine is expected to have for you.

If you have any concerns about this medicine, ask your doctor or pharmacist.

Keep this leaflet in a safe place. You may need to read it again.

What DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is used for

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is a simple phosphate salt used to quickly increase the amount of phosphate in your body.

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection works by providing a source of phosphate for your body to use.

Your doctor may have prescribed it for another reason.

Ask your doctor if you have any questions about why this medicine has been prescribed for you.

This medicine is available only with a doctor’s prescription.

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is not addictive.

Before you are given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection

When you must not be given it

You should not be given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection if you have any of the following medical conditions:

  • a dangerously fast heart beat
  • severe burns
  • acute dehydration
  • heat cramps
  • kidney disease causing less urine than normal or severe kidney disease
  • certain types of kidney stones
  • higher than normal levels of adrenal hormones known as hyperadrenalism
  • lower than normal levels of adrenal hormones known as Addison’s disease
  • high blood levels of potassium or phosphate or low blood levels of calcium.

Before you are given it

Tell your doctor if you have allergies to any other medicines, foods, preservatives or dyes.

Tell your doctor if you have or have had any other health problems/medical conditions, including:

  • kidney disease
  • pancreatic disease
  • parathyroid problems
  • muscle disease
  • heart disease
  • slow or irregular heart beat
  • rickets
  • electrolyte disturbances.

Tell your doctor if you are pregnant or intend to become pregnant. Your doctor will discuss the risks and benefits of you being given this medicine during pregnancy.

Tell your doctor if you are breastfeeding or plan to breast-feed. Your doctor will discuss the risks and benefits of you being given this medicine when breast-feeding.

If you have not told your doctor about any of the above, tell them before you are given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection.

Taking other medicines

Tell your doctor if you are taking any other medicines, including medicines that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and DBL™ Potassium Dihydrogen Phosphate Concentrated Injection may interfere with each other. These include:

  • medicines containing calcium, potassium or phosphate
  • medicines that reduce the excretion of potassium such as spironolactone or triamterene
  • cardiac glycosides such as digoxin
  • medicines used to treat high blood pressure and some heart conditions known as ACE inhibitors
  • salicylates
  • non-steroidal anti-inflammatory drugs such as aspirin or ibuprofen.

These medicines may be affected by DBL™ Potassium Dihydrogen Phosphate Concentrated Injection or may affect how well it works. You may need different amounts of your medicine, or you may need to take different medicines.

Your doctor or pharmacist has more information on medicines to be careful with or avoid while being given this medicine.

How DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is given

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is given as a slow injection into a vein.

It must only be given by a doctor or nurse.

Your doctor will decide what dose of DBL™ Potassium Dihydrogen Phosphate Concentrated Injection you will receive and how long you will receive it for. This depends on your medical condition and other factors, such as your weight.

Sometimes only a single dose of DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is required.

If you are given too much (overdose)

As DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is given to you under the supervision of your doctor it is unlikely that you will receive an overdose.

However, if you experience severe side effects, tell your doctor immediately, contact the Poisons Information Centre (telephone 13 11 26 in Australia) for advice, or go to Accident and Emergency at the nearest hospital. You may need urgent medical attention.

While you are being given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection

Things you must do

If you are about to be started on any new medicine, remind your doctor and pharmacist that you have been given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection.

Tell any other doctors, dentists, and pharmacists who treat you that you have been given this medicine.

If you are going to have surgery, tell the surgeon or anaesthetist that you have been given this medicine. It may affect other medicines used during surgery.

If you are about to have any blood tests, tell your doctor that you have been given this medicine. It may interfere with the results of some tests.

Things to be careful of

If you feel light-headed, dizzy or faint when getting out of bed or standing up, get up slowly. Standing up slowly, especially when you get up from bed or chairs, will help your body get used to the change in position and blood pressure. If this problem continues or gets worse, talk to your doctor.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are being given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection.

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection helps most people with low levels of phosphate in their bodies, but it may have unwanted side-effects in a few people.

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side-effects.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor or pharmacist if you notice any of the following and they worry you:

  • swelling of feet or lower legs
  • weight gain.

The above list includes the more common side effects of your medicine. They are usually mild and short-lived.

Tell your doctor immediately if you notice any of the following:

  • muscle weakness or muscle cramps
  • convulsions (fits)
  • confusion
  • tiredness
  • headache, dizziness or light-headedness
  • irregular or slow heart rate or chest pain
  • sweating, trembling
  • anxiety
  • tingling or numbness of the lips, hands or feet
  • breathing difficulties
  • increased thirst and decrease in urination.

The above list includes serious side effects that may require medical attention. Serious side effects are rare.

Tell your doctor or pharmacist if you notice anything that is making you feel unwell.

Other side effects not listed above may also occur in some people.

Some side effects can only be found when your doctor does tests from time to time to check your progress.

After being given DBL™ Potassium Dihydrogen Phosphate Concentrated Injection

Storage

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection will be stored in the pharmacy or on the ward. The injection is kept in a cool dry place where the temperature stays below 25°C.

Product description

What it looks like

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is a clear, colourless solution.

Ingredients

Each 10 mL ampoule of DBL™ Potassium Dihydrogen Phosphate Concentrated Injection contains 1.361 g of potassium phosphate monobasic and water for injection.

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection does not contain gluten, lactose, sucrose, tartrazine or any other azo dyes.

Sponsor

Pfizer Australia Pty Ltd
Sydney NSW
Toll Free Number: 1800 675 229
www.pfizermedinfo.com.au

DBL™ Potassium Dihydrogen Phosphate Concentrated Injection is available in the following presentation:

  • 1.361 g/10 mL ampoule
    AUST R 16263

This leaflet was prepared in November 2021.

Published by MIMS December 2021

BRAND INFORMATION

Brand name

DBL Potassium Dihydrogen Phosphate Concentrated Injection

Active ingredient

Potassium phosphate, monobasic

Schedule

Unscheduled

 

1 Name of Medicine

Monobasic potassium phosphate.

2 Qualitative and Quantitative Composition

Each 10 mL ampoule contains 1.361 g of monobasic potassium phosphate (KH2PO4) in Water for Injection. The pH of the solution is approximately 4.5. Each mL of injection contains 1 mmol of potassium ions, 1 mmol of phosphate ions and 2 mmol of hydrogen ions.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Monobasic potassium phosphate is a white, odourless, granular or crystalline powder, or colourless crystals. It is freely soluble in water and practically insoluble in alcohol.
DBL Potassium Dihydrogen Phosphate Concentrated Injection is a clear, colorless, sterile solution.

4 Clinical Particulars

4.1 Therapeutic Indications

Treatment of severe hypophosphataemia (serum levels less than 0.3 mmol/L) and other degrees of hypophosphataemia when oral therapy is not possible.
The cause of hypophosphataemia should be identified and treated.

4.2 Dose and Method of Administration

Dosage.

For the treatment of severe hypophosphataemia, the following doses are suggested.

Adults.

Up to 10 mmol phosphate administered over 12 hours. The dose may be repeated at 12 hour intervals until serum phosphate exceeds 0.3 mmol/L.

Children.

0.15-0.33 mmol/kg administered over 6 hours. The dose may be repeated at 6 hour intervals until serum phosphate exceeds 0.6 mmol/L. The dose should not exceed the maximum recommended adult dose. The rate of infusion should not exceed 0.2 mmol/kg/h.

Method of administration.

DBL Potassium Dihydrogen Phosphate Concentrated Injection is administered by slow intravenous infusion. The injection must be diluted before use.

Dilution.

DBL Potassium Dihydrogen Phosphate Concentrated Injection must be diluted before use. The drug can be given in 0.9% sodium chloride or 5% glucose solution. It should be administered by slow infusion to avoid phosphate intoxication.

Monitoring.

Serum sodium, potassium, phosphate and calcium concentrations and renal function should be monitored every 12 to 24 hours during therapy.
Conversion to oral phosphate therapy should occur as soon as possible.

Dosage adjustments.

Renal impairment.

Dose should be reduced. Use of phosphates in severe renal impairment is contraindicated (see Section 4.3 Contraindications).

4.3 Contraindications

DBL Potassium Dihydrogen Phosphate Concentrated Injection is contraindicated in:
Patients with severe renal function impairment (less than 30% normal), since there is an increased risk of hyperphosphataemia in these patients.
Patients with hyperphosphataemia, since phosphate therapy will exacerbate the condition.
Patients with hypocalcaemia, due to the close relationship between hypocalcaemia and hyperphosphataemia.
Patients with hyperkalaemia, since the potassium in the injection may exacerbate the condition.
Addison's disease since there is an increased risk of hyperkalaemia in these patients.
Urolithiasis (magnesium ammonium phosphate type, infected), since it may exacerbate the condition.
Renal impairment with oliguria and azotaemia.
Ventricular fibrillation.
Hyperadrenalism associated with adrenogenital syndrome.
Extensive tissue breakdown as in severe burns.
Acute dehydration.
Heat cramps.
Increased sensitivity to potassium administration as in adynamia episodica hereditaria or congenital paramytonia.

4.4 Special Warnings and Precautions for Use

Potassium.

The use of potassium salts in patients with chronic renal disease, adrenal insufficiency or any other condition which impairs potassium excretion, requires particularly careful monitoring of the serum potassium concentration and appropriate dosage adjustment.
Potassium should be used with caution in diseases associated with heart block since increased serum potassium may increase the degree of block.

Hyperkalaemia.

Monobasic potassium phosphates should be avoided in patients with hyperkalaemia. Sodium phosphates may be substituted.
In patients with impaired mechanisms for excreting potassium, administration of potassium salts can produce hyperkalaemia and cardiac arrest. This is an important concern in patients given IV potassium. Potentially fatal hyperkalaemia can develop rapidly and be asymptomatic. In patients being given potassium especially by IV, monitoring of serum electrolytes, the ECG and the patient's clinical status is indicated.

Phosphate.

Phosphate should be administered with caution in conditions where high phosphate levels may be encountered, such as hypoparathyroidism, chronic renal disease, acute dehydration, pancreatitis, rhabdomyolysis, severe renal insufficiency and extensive tissue damage (such as severe burns).
Phosphate should be administered with caution in conditions where low calcium levels may be encountered, such as hypoparathyroidism, osteomalacia, chronic renal disease, acute pancreatitis, rhabdomyolysis, rickets, myotonia congenita, and heart disease (particularly in digitalised patients) (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions) since these conditions may be exacerbated by the potassium in the injection.
Caution should be used where patients may be hypocalcaemic.
Serum electrolyte and especially phosphate levels in the body and renal function should be monitored during treatment.
Phosphates should not be administered to patients with severely impaired renal function. Aluminium, calcium, or magnesium salts should not be administered concomitantly with phosphates as they bind phosphate thus impairing its absorption from the gastro-intestinal tract.

Use in the elderly.

No data available.

Paediatric use.

No data available.

Effects on laboratory tests.

Saturation of bone binding sites by phosphate ions may cause decreased bone uptake of technetium Tc99m labelled contrast agents in bone imaging.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Angiotensin converting enzyme (ACE) inhibitors.

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may result in hyperkalaemia, especially in patients with renal impairment.

Calcium containing medicines.

Concurrent use of DBL Potassium Dihydrogen Phosphate Concentrated Injection and calcium containing medicines may increase the risk of deposition of calcium in soft tissues.

Digitalis glycosides.

The administration of DBL Potassium Dihydrogen Phosphate Concentrated Injection in digitalised patients with severe or complete heart block may result in hyperkalaemia.

Potassium sparing diuretics.

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may result in hyperkalaemia, especially in patients with renal impairment.

Nonsteroidal anti-inflammatory agents (NSAIDs).

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may result in hyperkalaemia, especially in patients with renal impairment.

Phosphate containing medicines.

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may result in hyperphosphataemia, especially in patients with impaired renal function.

Potassium containing medicines.

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may result in hyperkalaemia, especially in patients with renal impairment.

Salicylates.

Concurrent use with DBL Potassium Dihydrogen Phosphate Concentrated Injection may increase the serum concentration of salicylates, since salicylate excretion is decreased in acidified urine. This may result in toxic salicylate concentrations when phosphate is administered to patients already stabilized on salicylates.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
Animal reproduction studies have not been conducted with this product. It is not known whether this product can adversely affect the foetus when administered to a pregnant woman. Therefore, DBL Potassium Dihydrogen Phosphate Concentrated Injection is not recommended for use during pregnancy.
 It is not known whether phosphates are excreted into breast milk, therefore, DBL Potassium Dihydrogen Phosphate Concentrated Injection is not recommended for use during lactation.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

Cardiovascular.

Uncommon: hypotension. Rare: myocardial infarction.

Endocrine/ metabolic.

Uncommon: fluid retention as indicated by swelling of feet or lower legs or weight gain; hyperkalaemia leading to confusion, tiredness or weakness, irregular or slow heart rate, numbness or tingling around lips, hands or feet, unexplained anxiety, weakness or heaviness of legs, shortness of breath or troubled breathing; hypernatraemia leading to confusion, tiredness or weakness, convulsions, oliguria or decreased frequency of micturition, tachycardia, headache or dizziness, increased thirst; hyperphosphataemia, hypocalcaemia or hypomagnesaemia leading to convulsions, muscle cramps, numbness, tingling, pain or weakness in hands or feet, shortness of breath or troubled breathing, tremor; extraskeletal calcification as nephrocalcinosis has been reported in children with hypophosphataemic rickets treated with phosphate supplements.

Genitourinary.

Rare: acute renal failure.
The symptoms and signs of potassium intoxication include paraesthesias of the extremities, flaccid paralysis, listlessness, mental confusion, weakness and heaviness of the legs, fall in blood pressure, cardiac arrhythmias and heart block. Hyperkalaemia may exhibit the following ECG abnormalities: disappearance of the P-wave, widening and slurring of QRS complex, changes of the S-T segment, tall-peaked T-waves. Nausea, vomiting, diarrhoea and abdominal discomfort have been reported.
Treatment of adverse effects involves withdrawal of phosphate, general supportive measures, and correction of serum-electrolyte concentrations, especially calcium (see Section 4.9 Overdose).

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration 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 at www.tga.gov.au/reporting-problems.

4.9 Overdose

Phosphate.

Excessive administration of phosphate, particularly by the intravenous route, may cause hyperphosphataemia but this rarely occurs unless there is renal failure. Hyperphosphataemia may also occur in the presence of acidosis, acromegaly, haemolysis, hypoparathyroidism, tissue destruction, or vitamin D toxicity. Symptoms associated with hyperphosphataemia include muscle weakness, paraesthesia, convulsions, cardiomyopathy, respiratory failure and haematological abnormalities.
Hyperphosphataemia leads in turn to hypocalcaemia, which may be severe, and to ectopic calcification. Secondary hyperparathyroidism may develop in the presence of renal failure.
Crystal deposition may occur in important structures including blood vessels of the eye, lung, heart and kidney. Fatal alveolar diffusion block has occurred, the risk being greater if the patient is alkalotic.

Treatment.

Treatment of overdosage involves the following measures:
immediate cessation of phosphate therapy;
correction of serum electrolyte concentrations, especially calcium;
general supportive treatment.

Potassium.

If excretory mechanisms are impaired or if IV potassium is administered too rapidly, potentially fatal hyperkalaemia can result (see Section 4.3 Contraindications; Section 4.4 Special Warnings and Precautions for Use). However, hyperkalaemia is usually asymptomatic and may be manifested only by an increased serum potassium concentration and characteristic ECG changes (peaking of T-waves, loss of P-wave, depression of S-T segment, and prolongation of the QT interval). Late manifestations include muscle paralysis and cardiovascular collapse from cardiac arrest. Should any of these manifestations occur, discontinue potassium administration immediately.

Treatment.

If hyperkalaemia develops, the following measures should be considered: elimination of foods and medications containing potassium and of potassium-sparing diuretics; IV administration of 300 to 500 mL/hour of 10% glucose solution containing 10 to 20 units of insulin/1000 mL; correction of acidosis, if present, with IV sodium bicarbonate; use of exchange resins, haemodialysis, or peritoneal dialysis; in presence of life-threatening cardiac arrhythmias, IV administration of 10 to 50 mL calcium gluconate 10% over 5 minutes. Continuous ECG monitoring is mandatory.
In treating hyperkalaemia in digitalised patients, too rapid a lowering of the serum potassium concentration can produce digitalis toxicity.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

The majority (80%) of the body's phosphate is found as calcium phosphate in the skeleton, where it gives rigidity to the bone. The remainder is found in soft tissues. Phosphate is the principle anion of intracellular fluid. In body fluids, phosphate is present mainly as divalent hydrogen phosphate (HPO42-) ions (approximately 80%) and monovalent dihydrogen phosphate (H2PO4-) ions (approximately 20%).
Apart from its essential role in bone structure, phosphate is also important in many metabolic and enzymatic pathways. It is involved in energy storage and transfer, the utilisation of B complex vitamins, the buffering of body fluids, and in the renal excretion of hydrogen ions.
Hypophosphataemia may arise from a variety of causes including primary hyperparathyroidism, vitamin D deficiency, X-linked familial hypophosphataemia, alcoholism, hepatic failure and septicaemia. The symptoms of hypophosphataemia include muscle weakness, paraesthesia, convulsions, cardiomyopathy, respiratory failure and haematological abnormalities. Prolonged hypophosphataemia may result in rickets or osteomalacia.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

The normal concentration range of phosphate in plasma is 0.8 to 1.5 mmol/L.
Phosphate is primarily excreted in the urine. Over 90% of plasma phosphate is filtered in the kidneys with the majority being reabsorbed in the proximal tubule. Parathyroid hormone decreases the tubular reabsorption of phosphate, thereby increasing urinary excretion. In addition, serum phosphate levels are inversely related to serum calcium levels and to renal metabolism of vitamin D. A decrease in serum calcium concentration will result in increased serum phosphate levels.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Water for injections.

6.2 Incompatibilities

Phosphates are reported to be incompatible with calcium or magnesium containing solutions. Admixture will lead to precipitates being formed in the solution. Solutions containing other cations such as iron and aluminium may also form precipitates when added to the product.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 25°C.

6.5 Nature and Contents of Container

Strength.

Potassium phosphate monobasic 136.1 milligrams/mL.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of in accordance with local requirements.

6.7 Physicochemical Properties

Chemical structure.

The molecular formula of potassium phosphate monobasic is KH2PO4. Its molecular weight is 136.1.

CAS number.

7778-77-0.

7 Medicine Schedule (Poisons Standard)

Unscheduled.

Summary Table of Changes