For the use of a Registered Medical Practitioner, Hospital or Laboratory only.
1. Description
KayCut contains Calcium Polystyrene Sulphonate powder. It is orange flavour, odourless powder with a sodium content less than 1 mg/g. The calcium content of KayCut is about 8% w/w (1.6-2.4 mmol/g).
2. Composition
KayCut – Each sachet contains:
- Calcium Polystyrene Sulphonate BP – 15 g
- Excipients – q.s.
KayCut Suspension – Each 60 mL suspension contains:
- Calcium Polystyrene Sulphonate BP – 15 g, in a palatable base – q.s.
3. Dosage Form
KayCut – Powder (sachet) for oral administration
KayCut Suspension – Oral Suspension (for oral administration)
4. Pharmacology
Pharmacodynamics
Calcium polystyrene sulfonate is a non-absorbable cation-exchange resin that acts locally within the gastrointestinal tract.
The resin exchanges calcium ions for potassium ions in the intestinal lumen, predominantly in the large intestine, where potassium secretion is greatest.
The bound potassium remains attached to the resin and is eliminated in the faeces, thereby reducing total body potassium.
As potassium is removed from the body, serum potassium concentrations gradually decrease, helping to correct hyperkalaemia.
The resin is not selective for potassium and may also exchange calcium for other cations such as magnesium, which can contribute to electrolyte disturbances during therapy.
Calcium Polystyrene Sulphonate is a cation exchange resin prepared in the calcium phase.
Pharmacokinetics
Because calcium polystyrene sulfonate is a non-absorbable ion-exchange resin, conventional pharmacokinetic parameters such as systemic bioavailability and plasma half-life are not applicable.
Absorption
Calcium polystyrene sulfonate is not absorbed from the gastrointestinal tract.
It remains within the intestinal lumen and exerts its action locally by exchanging calcium for potassium.
Distribution
There is no systemic distribution, as the resin is not absorbed into the bloodstream.
Its activity is confined to the gastrointestinal tract.
Metabolism
Calcium polystyrene sulfonate is not metabolised.
The resin remains chemically unchanged while exchanging calcium ions for potassium ions within the intestine.
Elimination
The resin, together with the bound potassium, is eliminated unchanged in the faeces.
The potassium-lowering effect develops gradually over several hours and may require hours to days to achieve the desired reduction in serum potassium; therefore, it is not suitable as sole therapy for life-threatening hyperkalaemia, where more rapid interventions are required.
5. Indications
- For the treatment of hyperkalaemia associated with anuria and severe oliguria.
- For the treatment of hyperkalaemia in patients requiring dialysis and in patients on regular haemodialysis or on prolonged peritoneal dialysis.
- For the treatment of hyperkalaemia associated with use of RAASi, NSAIDs and potassium-sparing diuretics.
6. Contraindications
KayCut is contraindicated in patients having:
- A history of hypersensitivity to polystyrene sulphonate resins
- Serum potassium levels less than 5 mmol/L
- Conditions associated with hypercalcaemia (eg. hyperparathyroidism, multiple myeloma, sarcoidosis or metastatic carcinoma)
- Obstructive bowel disease
KayCut should not be administered orally to neonates and is contraindicated in neonates with reduced gut motility (eg. post-operatively or drug-induced)
7. Precautions
The possibility of severe potassium depletion should be considered, and adequate clinical and biochemical control is essential during treatment, especially in patients on digoxin. Administration of the resin should be stopped when the serum potassium falls to 5 mmol/litre.
Like all cation-exchange resins, KayCut is not totally selective for potassium in its actions. Serum calcium levels should be estimated at weekly intervals to detect the early development of hypercalcaemia and the dose of resin adjusted to levels at which hypercalcaemia and hypokalaemia are prevented. Hypomagnesaemia may also occur, and serum magnesium levels should be monitored. Patients should be monitored for all applicable electrolyte disturbances.
In the event of clinically significant constipation, treatment should be discontinued until normal bowel movement resumes. Magnesium containing laxatives should not be used.
With oral administration, care should be taken to avoid aspiration, which may lead to bronchopulmonary complications.
Gastrointestinal stenosis, intestinal ischaemia and its complications (necrosis and perforation) may occur in patients treated with polystyrene sulphonate, especially in patients using sorbitol. Therefore, concomitant use of sorbitol with calcium polystyrene sulphonate is not recommended.
Since effective lowering of serum potassium with KayCut may take hours to days, treatment with this drug alone may be insufficient to rapidly correct severe hyperkalaemia, often associated with states of rapid tissue breakdown, e.g., burns or trauma. In such instances, some form of dialysis may be imperative. If hyperkalaemia is marked to constitute a medical emergency, immediate treatment with intravenous glucose and insulin or intravenous sodium bicarbonate may be necessary as a temporary measure to lower serum potassium while other long-term potassium-lowering therapy is being prepared.
Use in Pregnancy (Category B2): No data is available regarding the use of polystyrene sulphonate resins in pregnancy. The administration of KayCut in pregnancy is not advised unless the potential benefits outweigh any potential risks.
Use in Lactation: No data is available regarding the use of polystyrene sulphonate resins in lactation. The administration of KayCut during breast-feeding, therefore, is not advised unless the potential benefits outweigh any potential risks.
Paediatric Use: In Neonates, KayCut should not be given by the oral route. In Children and Neonates, particular care should be observed with rectal administration, as excessive dosage or inadequate dilution could result in impaction of the resin. Due to the risk of digestive haemorrhage or colic necrosis, particular care should be observed in premature infants or low birth weight infants.
8. Drug Interactions
Concomitant use of sorbitol with Calcium Polystyrene Sulphonate is not recommended due to cases of intestinal necrosis and other serious gastrointestinal adverse reactions, which may be fatal.
Cation donating agents may reduce the potassium binding effectiveness of KayCut.
Non-absorbable cation containing antacids and laxatives (such as magnesium hydroxide) and concomitant oral use of cation exchange resins has been reported to cause systemic alkalosis.
Aluminium Hydroxide: Intestinal obstruction due to concretions of aluminium hydroxide has been reported when taken in combination with the resin (sodium form).
Digoxin: The toxic effects of digoxin on the heart, especially ventricular arrhythmias and AV nodal depression, are likely to be exaggerated if hypokalaemia and/or hypercalcaemia develop.
Lithium: Possible decreases of lithium absorption.
Thyroxine: Possible decreases of thyroxine absorption.
9. Adverse Effects
Metabolism and Nutrition Disorders: Cases of hypomagnesaemia have been reported. Hypercalcaemia has been reported in well-dialysed patients receiving calcium resin and occasionally in patients with chronic renal failure. Many patients in chronic renal failure have low serum calcium and high serum phosphate, but some, who cannot be screened out beforehand, show a sudden rise in serum calcium to high levels after therapy. The risk emphasizes the need for adequate biochemical control.
Gastrointestinal Disorders: Gastric irritation, anorexia, nausea, vomiting, constipation and occasional diarrhoea may also occur. Faecal impaction following rectal administration has been reported in children and gastrointestinal concretions following oral administration to neonates. Gastrointestinal stenosis and intestinal obstruction have also been reported, possibly due to coexisting pathology, excessive dosage or inadequate dilution of the resin.
Gastrointestinal ischaemia, ischaemic colitis, gastrointestinal tract ulceration or necrosis, which could lead to intestinal perforation, have been reported following administration of calcium polystyrene sulphonate, which is sometimes fatal.
Respiratory, Thoracic and Mediastinal Disorders: Some cases of acute bronchitis and/or bronchopneumonia associated with inhalation of particles of calcium polystyrene sulphonate have been observed.
10. Dosage & Administration
KayCut is for oral or rectal administration only. The dosage recommendation should be determined on the basis of regular clinical and serum electrolyte monitoring.
Adults Including the Elderly – Oral: Usual dose of 15 g to be taken three or four times a day. The resin is given by mouth as a suspension in a small amount of water (3-4 mL per gram of resin), or it may be mixed with some sweetened vehicle (but not fruit juices, which contain potassium).
Adults Including the Elderly – Rectal: In cases where vomiting or upper gastrointestinal problems including paralytic ileus may make oral administration difficult, the resin may be given rectally in a suspension of 30 g resin in 150 mL water or 10% dextrose in water, as a daily retention enema. In the initial stages, administration by this route as well as orally may help to achieve a more rapid lowering of the serum potassium level.
The enema should, if possible, be retained for at least nine hours, following which the colon should be irrigated to remove the resin. If both routes are used at first, it is probably unnecessary to continue rectal administration once the oral resin has reached the rectum.
Children – Oral: Lower doses should be used, as a guide, 1 mmol potassium per gram of resin. The initial dose is 1 g/kg body weight daily in divided doses, in acute hyperkalaemia.
Children – Rectal: When the resin cannot be given by mouth, it may be given rectally using a dose at least as great as that which would have been given orally, diluted in the same ratio as described for adults. Following retention of the enema, the colon should be irrigated to ensure adequate removal of the resin.
Neonates: KayCut should not be given by the oral route and only rectal administration should be considered. With rectal administration, the minimum effective dosage within the range 0.5 g/kg to 1 g/kg should be employed, diluted as for adults and with adequate irrigation to ensure recovery of the resin.
Directions For Use: Disperse the content of the sachet in 50-60 mL of previously boiled and cooled water to form a suspension. It may be mixed with some sweetened vehicle like honey, etc., and should be consumed immediately. Do not mix in fruit juices.
KayCut Suspension: Shake well before use.
11. Overdosage
Hypokalaemia may manifest clinically by signs of irritability, confusion, delayed thought processes, severe muscle weakness, hyporeflexia or paralysis. ECG abnormalities may be evident and cardiac arrhythmias may occur. In the event of overdosage, appropriate measures should be taken to restore serum potassium levels to normal and to reduce blood calcium levels if these are raised. In addition, consideration should be taken to accelerate the elimination of the resin, particularly if intestinal motility is reduced.
12. Storage
KayCut – Store in a dry place at a temperature not exceeding 30°C. Protect from light.
KayCut Suspension – Store in a dry place at a temperature not exceeding 30°C. Protect from light. Do not freeze.
Keep the medicine out of reach of children.
Additional Information
Additional pharmacokinetic information
Absorption and Distribution: Calcium Polystyrene Sulphonate is not absorbed from the gastrointestinal tract. Calcium Polystyrene Sulphonate removes potassium from the body by exchanging it within the gut for calcium.
Metabolism and Excretion: For the most part, this action occurs in the large intestine, which excretes potassium to a greater degree than in the small intestine. The efficiency of potassium exchange is unpredictable and variable. The resin is not selective for potassium.
13. Presentation
KayCut – 15.3 g Powder in a sachet, 10 sachets in a box.
KayCut Suspension – 60 mL side-spout stand-up pouch.