Posten Injection (Dihydrogen Phosphate Potassium)

Adult administration

The dose should be determined based on fluid and electrolyte, acid-base balance as per individual patient needs. Monitor blood levels and administer potassium as a maximum rate of 20mmol per hour. For adults receiving total parenteral nutrition (TPN), phosphate of 12 to 15mmol should be diluted in 500mL of 50% dextrose injection.

Child administration

In children, administer 1.5 to 2mmol per kg of body weight daily, diluted in 500mL of 50% dextrose injection.

This drug is provided as an ampule injection and the glass container must be cut carefully. During cutting, glass shards may mix in, so extra caution is needed, especially when used for children or the elderly. This medication should not be administered to patients with certain diseases where hyperkalemia commonly occurs. For instance, dehydration, reduced kidney function, Addison's disease, and patients with weakness and convulsions may be at risk if they use this drug. Also, administration should be avoided in cases of hyperphosphatemia, hypocalcemia, oliguria, anuria, and in patients who already have hyperkalemia. Patients with renal diseases such as renal failure or adrenal insufficiency, those with potassium retention, heart failure patients, and patients with sickle cell anemia should use this drug with caution. This medication may cause phosphorus toxicity and potassium toxicity. Phosphorus toxicity can lower blood calcium levels, leading to muscle spasms or hypocalcemia, while potassium toxicity may cause severe symptoms such as sensory disturbances, muscle weakness, confusion, cardiac arrhythmias, etc. Additionally, gastrointestinal disturbances such as nausea, vomiting, and abdominal pain may occur, so caution is advised. This drug contains phosphorus and potassium, so the total amount of potassium in the fluid must be considered during dosage adjustments. Increased dosing of potassium phosphate may require the addition of calcium, so calcium should be provided separately. When administering to patients with renal failure or adrenal insufficiency, the risk of potassium toxicity is higher, so extra caution is needed. This drug may reduce the effects of cardiac glycosides, and concomitant use with drugs such as aldosterone antagonists, potassium-sparing diuretics, and ACE inhibitors may decrease renal potassium excretion, leading to dangerously elevated potassium levels. Caution is also needed when used alongside nephrotoxic medications such as nonsteroidal anti-inflammatory drugs or some antibiotics, and the risk of gastrointestinal disturbances may increase when used with anticholinergic agents. The safety of this drug during pregnancy has not been fully established, so it should only be used when the benefits of treatment exceed the risks. In cases of overdose, symptoms of phosphorus and potassium toxicity may occur, requiring immediate cessation of administration and appropriate treatment to replenish blood calcium and lower phosphorus and potassium levels. This drug should not be mixed with calcium preparations as it may cause precipitation, and it should be diluted and infused slowly before administration. Any remaining medication after use should be discarded, and careful management is required to prevent phosphorus and potassium toxicity.

Serious side effects

Peripheral sensory disturbances, weakness or paralysis, lethargy, confusion, leg heaviness, fatigue, hypotension, serious arrhythmias, cardiac block, cardiac arrest, reduced heart function, arrhythmias, hypocalcemia due to decreased blood calcium levels, tetany.

Mild side effects

• Nausea
• vomiting
• and abdominal pain may occur.

This drug should be stored in a sealed container to avoid contact with air, ideally in a cool place between 15 to 30 degrees Celsius. This way, the effectiveness of the medication can be maintained.

Appearance

A colorless and transparent injection solution contained in a colorless and transparent vial or ampule.

Package unit

20ml/ampule X 50