Two drugs, one exit. Both of them pull a poison out of the body through the STOOL 💩 — lactulose takes out AMMONIA in cirrhosis, and sodium polystyrene sulfonate takes out POTASSIUM in hyperkalemia. If the client is not stooling, neither drug is working.
💩 Lactulose = LOSE ammonia“Lose ammonia via LOOSE bowels.” Goal = 2–3 soft stools per day → cognition improves.
🚪 Kayexalate = K EXITsHelps the large intestine remove excess K⁺. Given when K⁺ is over 5.0.
🩺 Assess the BELLY firstBowel sounds, distention, recent stool pattern. No bowel function = hold SPS.
🚨 SPS is NOT the emergency drugIt works over hours. Peaked T waves → IV calcium gluconate FIRST.
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WHAT IT DOES
STEP 1 · THE MECHANISM
Both drugs use the same exit — the colon. Only the passenger is different.
🧠 LACTULOSE — memory trick: L·A·C
L — LAXATIVE for…
A — AMMONIA levels — DECREASE
C — COGNITION returns — “improved mental status”
Given to decrease ammonia levels in CIRRHOSIS clients, to treat HEPATIC ENCEPHALOPATHY — “cloudy brain.”
How it works: lactulose is a sugar the body cannot absorb. Gut bacteria ferment it, which acidifies the colon. That acid converts absorbable ammonia (NH₃) into trapped ammonium (NH₄⁺) — and the laxative effect sweeps it out in the stool.
🧠 “LACTO-LOSE — Lose ammonia via LOOSE bowels.” The whole drug is in the name. No stool, no ammonia leaving, no clearing of the brain.
🔬 Follow the ammonia — why a liver problem becomes a brain problem
🧠 “Bad liver, cloudy brain — flush the plumbing.” The liver is the ammonia filter. When the filter is scarred shut, the only remaining exit is the stool — and lactulose is what opens it.
❌ What lactulose does NOT do — three NCLEX “NO”s
NO — there is no renal excretion of ammonia with lactulose. It leaves in the stool, not the urine.
NO — it does NOT decrease portal hypertension.
NO — abdominal distention/ascites will NOT improve with lactulose.
NOT a diuretic. If the answer choice mentions urine output, it is wrong.
🧠 “Lactulose works in the toilet, not the bedpan.” Stool — never urine, never the belly size, never the portal pressure.
🚪 SPS memory trick: K EXIT
Kayexalate — helps K⁺ to EXIT the body.
Given to decrease HIGH potassium (over 5.0). It helps the large intestine remove excess K⁺ from the body.
How it works: it is a resin you swallow (or give as a retention enema). In the colon it trades sodium for potassium — it lets go of Na⁺, grabs K⁺, and the whole package leaves in the stool.
🧠 “Kay-EXIT-alate.” The K is literally in the name and so is the exit. Sodium in, potassium out, through the back door.
🔬 The resin trade — how SPS pulls potassium out of the colon
TIMING SPS works over hours, not minutes — it is the “remove it” step, never the “save the heart right now” step.
🧠 “The resin is a school bus: it drops off sodium and picks up potassium.” Then the bus drives out with the stool.
⚖️ Same exit, different passenger — compare the two drugs
⚡ HYPOkalemia — diarrhea dumps potassium; watch for muscle weakness, flat T waves and U waves. Low K⁺ actually makes encephalopathy worse.
🌊 HYPERnatremia — losing water faster than sodium
🍑 Perianal skin breakdown — barrier cream and gentle cleansing
🤢 Bloating, flatulence, cramping, a very sweet taste
Do NOT hold lactulose simply because the client is having loose stools — the loose stools are the drug working. Report and reassess if there are more than about 4–5 watery stools a day, or if there are signs of dehydration or a falling potassium.
Assess the brain every shift: orientation, handwriting sample, asterixis (the flapping hand tremor when the wrists are extended), slurred speech, fetor hepaticus, and increasing lethargy. Falls & aspiration precautions for a confused client.
🧠 “Two to three, that's the key.” Under 2 stools = ask for a dose increase. Way over 3 = call about dehydration and potassium. The stool count IS the vital sign for this drug.
🩺 SPS — assess the ABDOMEN and BOWEL FUNCTION before you give it
KEY POINTS
🤲 Assess the abdomen — distention, tenderness, rigidity, and bowel sounds in all four quadrants
💩 Recent bowel patterns & frequency of stools — when did they last have a bowel movement?
🧪 Potassium (K⁺) within normal limits — 3.5–5.0 mEq/L is the goal; recheck after the dose
🥤 Encourage the client to drink fluids after administrationHESI — it prevents fecal impaction from the resin
Also monitor:
🧂 Sodium load — the resin trades sodium in. Watch for fluid overload in heart failure, kidney disease and cirrhosis: edema, crackles, weight gain, JVD.
📉 Overshoot into HYPOkalemia — recheck the K⁺; also watch calcium and magnesium, which can drop.
💩 Constipation/impaction — that is why fluids afterward are the tested teaching point.
🕐 Onset is hours. Repeat EKGs and potassium levels while waiting.
💊 Separate other oral medications — the resin can bind them.
🧠 “No bowel sounds, no Kayexalate.” The drug can only leave through a moving bowel. Listen before you give.
🚨 EMERGENCY ORDER — hyperkalemia: SPS is step 4, not step 1
1
🫀 IV CALCIUM GLUCONATE — stabilizes the myocardium in minutes. It does NOT lower the potassium.
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2
💉 Regular INSULIN + dextrose (D50) — shifts K⁺ into cells; recheck the blood glucose.
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3
🌬️ Nebulized albuterol · sodium bicarbonate if acidotic — more shifting.
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4
🚪 REMOVE IT — sodium polystyrene sulfonate (or patiromer / sodium zirconium cyclosilicate) + furosemide if the kidneys work. This is where SPS lives — hours, not minutes.
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5
🩺 DIALYSIS — definitive, and the expected answer in renal failure.
Simultaneously: cardiac monitor, stop every potassium source (IV fluids with K⁺, K⁺-sparing diuretics, ACE inhibitors/ARBs, salt substitutes, high-K⁺ foods), and repeat the level.
🧠 “C BIG K DROP” — Calcium · Bicarb · Insulin · Glucose · Kayexalate · Diuretic · Dialysis. Kayexalate is the K in the middle — never the C at the front.
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TEACH
STEP 3 · WHAT THE CLIENT NEEDS TO HEAR
Both drugs fail at home for the same reason — the client stops them because of the stools.
✅ LACTULOSE teaching
💩 “Loose stools are expected and they are the point.” Aim for 2–3 soft stools per day — not watery, not none.
📞 Call the provider if: no stool in 24–48 hours, more than 4–5 watery stools a day, worsening confusion, dizziness on standing, or a weight drop.
🚫 Do not stop the medication on your own — stopping it lets ammonia climb and the confusion return.
🥤 Drink plenty of fluids to replace what the stools take.
🍹 Mix it with juice, water or milk to cut the sweetness; take it at a consistent time.
🧴 Protect the perianal skin — gentle cleansing and a barrier cream.
👨👩👧 Teach the family the warning signs of encephalopathy: new confusion, sleeping more, personality change, hand flapping (asterixis), slurred speech — those mean call, don't wait.
🩸 Report black/tarry stools or vomiting blood — a GI bleed dumps protein into the gut and spikes the ammonia.
🧠 “No poop, no thinking.” Blunt, but it is exactly what the client needs to remember: the stools are what clears the brain.
✅ SODIUM POLYSTYRENE SULFONATE teaching
🥤 “Drink fluids after you take it.”HESI — the single most tested teaching point; it prevents constipation and impaction.
💩 Report constipation or no bowel movement, new abdominal pain, distention, nausea or vomiting right away.
🧪 Keep the lab appointments — the potassium must be rechecked; the goal is 3.5–5.0 mEq/L.
🧂 Avoid salt substitutes — most of them are potassium chloride, which is exactly what you are removing.
🍌 Low-potassium diet while the level is high: limit banana, avocado, potato, spinach, orange/OJ, tomato, beans, melon, milk.
⚖️ Watch for swelling, weight gain or shortness of breath — the resin adds sodium.
💊 Space other oral medications — the resin can bind them and reduce their effect.
🚽 If given as a retention enema, it must be held in for the ordered time to work.
🧠 “Swallow it, then water it.” The resin only leaves the body if it stays soft and moving — fluids are the escort.
Loose stools are expected; never stop it on your own; fluids; report worsening confusion
Drink fluids after administration; report constipation; avoid salt substitutes; keep lab appointments
Goal
2–3 soft stools/day + improved mental status
K⁺ 3.5–5.0 mEq/L + normal EKG
🎯 Cover & check — 8 rapid-fire questions
Q1: A client with cirrhosis on lactulose has had 3 soft stools today. What do you do?
Continue the medication — 2 to 3 soft stools per day is the therapeutic goal. Do not hold it for "diarrhea."
Q2: How does lactulose lower ammonia?
It acidifies the colon, converting absorbable ammonia (NH₃) into trapped ammonium (NH₄⁺), and its laxative effect removes it in the STOOL — not the urine.
Q3: Name three things lactulose does NOT do.
It does not cause renal excretion of ammonia, it does not decrease portal hypertension, and abdominal distention/ascites will not improve with it. It is not a diuretic.
Q4: What lab abnormalities can lactulose cause?
Hypokalemia and hypernatremia from fluid and electrolyte loss with the stools, plus dehydration. Monitor daily weights and I&O.
Q5: What must you assess BEFORE giving sodium polystyrene sulfonate?
The abdomen and bowel function — bowel sounds, distention, and recent bowel patterns/frequency of stools. Hold it if bowel sounds are absent or there is an ileus/obstruction.
Q6: What is the tested teaching point after giving SPS?
Encourage the client to drink fluids after administration — it prevents constipation and fecal impaction. (HESI)
Q7: K⁺ is 6.8 with peaked T waves. Is SPS the first action?
No. Cardiac monitor and IV calcium gluconate first to stabilize the heart, then insulin + dextrose to shift it. SPS is the slower removal step (hours), and dialysis is definitive.
Q8: Which electrolyte problem can SPS itself create, and what else does it add to the body?
It can overshoot into hypokalemia, and it delivers a sodium load — watch for fluid overload in heart failure, kidney disease and cirrhosis.