Generic Name

GoLYTELY

Mechanism

• *High‑osmolar polyethylene glycol (PEG) 3350* with electrolytes and anionic surfactant.
• Creates an osmotic gradient that draws fluid into the colon, increasing stool volume.
• The surfactant disrupts the intestinal epithelium’s tight junctions, promoting water excretion.
• Result: rapid, even bowel evacuation with minimal electrolyte disturbance due to balanced electrolytes.

Pharmacokinetics

• Absorption: None (non‑absorbable large‑molecule polymer).
• Distribution: Limited to the gastrointestinal tract.
• Metabolism: None (inactive).
• Excretion: Eliminated unchanged in feces.
• Half‑life: Not applicable; clearance occurs through bowel evacuation.

Indications

• Adequate bowel cleansing for colonoscopy, flexible sigmoidoscopy, or colorectal surgery.
• Pre‑operative colon preparation in patients undergoing colectomy or low colorectal resections.
• Enhanced imaging of the colon for radiographic studies or capsule endoscopy.

Contraindications

• Absolute contraindications:
• Known hypersensitivity to PEG, polystyrene sulfonate, or any excipient.
• Relative contraindications:
• Severe dehydration, significant renal impairment, or electrolyte‑disturbed states.
• Warnings:
• Monitor for signs of fluid or electrolyte imbalance, especially in elderly or comorbid patients.
• Not recommended in patients with ileus or intestinal obstruction without specialist evaluation.

Dosing

• Adult regimen (usual 2‑day split dose):
• Day 1 (pre‑procedure): 295 mL of the solution diluted in 710 mL water, 4.5 L total; take in 3–4 h, then 500 mL water.
• Day 2 (pre‑procedure): 295 mL solution with 710 mL water, 4.5 L total; ingest 12–15 h before the procedure.
• Alternate 1‑day regimen:
• 295 mL + 710 mL water, 4.5 L total; complete within 4–6 h.
• Children (≥5 years): Adjust volume 0.6 mL/kg of solution with 1.2 mL/kg water, total volume 4.5 L.
• Swallowed undiluted or diluted; encourage sipping throughout to maintain hydration.

Adverse Effects

• Common:
• Nausea, vomiting, abdominal cramping, bloating, flatulence.
• Mild diarrhea (usually when fluid intake is inadequate).
• Serious:
• Severe dehydration (rare, especially in higher‑dose protocols).
• Electrolyte abnormalities (hyponatremia, hypokalemia).
• Rare allergic reaction: rash, pruritus, anaphylaxis.

Monitoring

• Baseline & during preparation:
• Vital signs: BP, heart rate, temperature.
• Serum electrolytes (Na⁺, K⁺, Cl⁻, HCO₃⁻) if risk of imbalance.
• Volume status: urine output, signs of dehydration.
• Post‑procedure:
• Verify adequate bowel cleanliness via FIT or endoscopic grading.
• Assess for lingering cramping or nausea.

Clinical Pearls

• Hydration is key: Encourage at least 32 oz of clear fluids accompanying the solution to prevent cramps and dehydration.
• Split‑dose protocol offers superior mucosal visibility and reduces completion time compared to 1‑day regimens.
• Tailor timing: For patients with delayed gastric emptying, consider prokinetic agents to expedite solution passage.
• Patient education: Instruct patients to see a stool sample if caffeine or food intolerances affect tolerability.
• Avoid with: incompatible with nasogastric tubes due to thick consistency; use PEG 3350 with split‑dose as an alternative.

*This concise drug card highlights critical information for medical students and clinicians, facilitating quick review and optimal patient care.*