Dosage & administration - Calcium Polystyrene 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 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).
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 hyperkalemia.
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: Calcium Polystyrene 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.
