Sodium polystyrene sulfonate is a medication employed in various medical situations to manage certain bodily imbalances. It functions as an ion-exchange resin, a type of substance that can swap one kind of ion for another. This medication is available in different forms, including oral suspensions and enemas.
Understanding Sodium Polystyrene Sulfonate Enema
Sodium polystyrene sulfonate (SPS) is an insoluble polymer cation-exchange resin. When administered as an enema, it works within the colon to remove excess potassium from the body. The resin exchanges its sodium ions for potassium ions present in the intestinal cells and lumen. The potassium then binds to the SPS resin, preventing its absorption into the bloodstream. This potassium-bound resin continues through the gastrointestinal tract and is eventually eliminated from the body through feces. Each gram of SPS can bind approximately 1 mEq of potassium.
Medical Applications
The primary medical application for sodium polystyrene sulfonate enema is the treatment of hyperkalemia, a condition characterized by abnormally high levels of potassium in the blood. Elevated potassium levels can be dangerous, potentially leading to serious heart rhythm abnormalities and muscle weakness. Conditions that can contribute to hyperkalemia include kidney failure, which impairs the body’s ability to excrete potassium, and the use of certain medications that can increase potassium levels. While SPS is effective in reducing potassium, it is not used for emergency treatment of life-threatening hyperkalemia due to its delayed onset of action, which can take hours to days.
Administration and Patient Experience
Administering a sodium polystyrene sulfonate enema involves several steps. A cleansing enema is often given beforehand to prepare the colon. The SPS medication, usually in a warm, body-temperature emulsion, is then introduced into the rectum using a soft rubber tube, extending about 20 centimeters into the sigmoid colon. The solution should be gently agitated during administration.
After the medication is fully administered, it is important for the patient to retain the enema in the colon for a specified period, usually between 30 to 60 minutes, or even several hours if possible, to allow sufficient time for potassium exchange. Patients might experience an urge to defecate or some abdominal discomfort during this retention period. Once the retention time is complete, the colon is irrigated with a non-sodium solution to remove the remaining resin. This procedure is generally performed in a medical setting under the supervision of a healthcare professional.
Important Safety Information
Sodium polystyrene sulfonate enema can cause several side effects, including constipation, nausea, vomiting, and abdominal discomfort. More serious, though rare, complications can occur, such as intestinal necrosis, where intestinal cells die due to insufficient blood supply, or intestinal perforation. Symptoms like severe abdominal pain, bloody stools, or fever warrant immediate medical attention.
The medication’s use requires careful medical supervision. It is generally not recommended for individuals with abnormal bowel functions, such as bowel obstruction or recent intestinal surgery, as this can increase the risk of serious complications. SPS can also contribute to sodium overload, requiring caution in patients with conditions like congestive heart failure or severe hypertension.