TRILYTE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRILYTE (TRILYTE).
TRILYTE (polyethylene glycol 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, ascorbic acid) is an osmotic laxative. The active components induce diarrhea by osmotically drawing water into the gastrointestinal lumen, thereby increasing stool volume and stimulating peristalsis. Sodium ascorbate and ascorbic acid enhance the osmotic effect.
| Metabolism | TRILYTE components are minimally absorbed and undergo negligible metabolism. Polyethylene glycol 3350 is excreted unchanged in feces. Ascorbic acid is metabolized via oxidation to dehydroascorbic acid, followed by further metabolism and renal excretion. |
| Excretion | Renal excretion of intact electrolyte ions; negligible drug excretion |
| Half-life | Not applicable; non-absorbed, acts locally in GI tract |
| Protein binding | Not applicable; non-absorbed |
| Volume of Distribution | Not applicable; non-absorbed |
| Bioavailability | Not applicable; not absorbed from GI tract |
| Onset of Action | Oral: 30-60 minutes for bowel evacuation |
| Duration of Action | Duration of bowel evacuation: 2-4 hours; complete clearance usually within 4-6 hours |
| Molecular Weight | 3350 |
Adults: 1 liter (L) orally every 10-15 minutes until 4 L total consumed; complete ingestion within 4 hours.
| Dosage form | FOR SOLUTION |
| Renal impairment | No dosage adjustment required for renal impairment; however, use with caution in severe renal impairment (CrCl <30 mL/min) due to risk of electrolyte disturbances. |
| Liver impairment | No dosage adjustment required for hepatic impairment; no specific Child-Pugh based modifications. |
| Pediatric use | Children 6 months to 12 years: 20 mL/kg orally per hour (maximum 1 L/hour) until rectal effluent clear; typical total dose 4 L. |
| Geriatric use | Use with caution; reduce rate of administration (e.g., 1 L over 2-3 hours) and monitor for electrolyte and fluid imbalances. |
| 1st trimester | Trilyte (polyethylene glycol 3350 with electrolytes) is commonly used for bowel cleansing prior to colonoscopy. In the first trimester, it is generally avoided unless necessary because of insufficient data on teratogenicity, but no specific malformations are reported. However, due to the potential for electrolyte disturbances and dehydration, it should be used with caution and only if clearly needed. |
| 2nd trimester | In the second trimester, use is considered relatively safer than in the first trimester, but caution is still advised. Electrolyte and fluid shifts may affect placental perfusion; however, no specific fetal risks have been established. Use only if the benefit outweighs the risk. |
| 3rd trimester | In the third trimester, use is generally not recommended due to potential effects on uterine activity and maternal fluid balance. There is a theoretical risk of premature labor or placental abruption from dehydration or electrolyte imbalance. Colonoscopy itself is typically avoided in late pregnancy unless urgent. |
Clinical note
Comprehensive clinical and safety monograph for TRILYTE (TRILYTE).
| Placental transfer | Polyethylene glycol 3350 is a large molecule (molecular weight ~3350 Da) with negligible absorption following oral administration. It does not cross the placenta significantly because it is not absorbed into maternal circulation. The electrolytes are naturally present and regulated. Therefore, fetal exposure is minimal to none. |
■ FDA Black Box Warning
There is no FDA-issued black box warning for TRILYTE.
| Serious Effects |
Gastrointestinal obstructionGastric retentionBowel perforationToxic colitisToxic megacolonIleusKnown hypersensitivity to any component of TrilyteSevere dehydration or electrolyte abnormalities (uncorrected)
| Precautions | Risk of severe fluid and electrolyte disturbances (e.g., hyponatremia, hypokalemia, hypocalcemia) leading to arrhythmias or seizures, especially in patients with renal impairment or those taking diuretics, Risk of acute phosphate nephropathy (although TRILYTE does not contain phosphate, similar risks apply due to electrolyte shifts), Mucosal ulcerations or ischemic colitis (rare), Aspiration risk, particularly in patients with impaired gag reflex or swallowing disorders |
| Food/Dietary | Avoid all solid foods during preparation. Only clear liquids (e.g., water, clear broth, apple juice, black coffee/tea, clear gelatin) are permitted. Avoid red or purple colored liquids as they may be confused with blood during colonoscopy. No dairy or alcohol. Resumption of normal diet is allowed after procedure unless otherwise instructed. |
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| Breastfeeding | Polyethylene glycol 3350 is not absorbed systemically after oral ingestion, so it is unlikely to be excreted into breast milk. However, the electrolytes in Trilyte (sodium, potassium, etc.) are normal bodily constituents and are not expected to cause harm. Nonetheless, caution is advised due to the potential for maternal dehydration or electrolyte imbalance affecting milk production. The manufacturer recommends caution, but the American Academy of Pediatrics considers polyethylene glycol compatible with breastfeeding. Use only if necessary and ensure maternal hydration. |
| Lactation Rating | L3 - Moderately Safe |
| Teratogenic Risk | TRILYTE (polyethylene glycol 3350 with electrolytes) is a bowel cleansing solution. No teratogenic effects are expected due to minimal systemic absorption. Pregnancy Category C: insufficient human data; animal studies not available. Use only if clearly needed. Risk to fetus unlikely, but caution in first trimester due to potential maternal dehydration/electrolyte imbalance. |
| Fetal Monitoring | Monitor maternal vital signs, hydration status, and serum electrolytes (sodium, potassium, chloride, bicarbonate) before and during TRILYTE administration. Assess for signs of fluid overload or dehydration. Fetal monitoring as clinically indicated if maternal status compromised. In pregnancy, evaluate uterine activity if large fluid shifts occur. |
| Fertility Effects | No known effects on fertility. Systemic absorption is negligible; thus, no impact on reproductive function or fertility expected. No animal studies available, but clinical experience with polyethylene glycol suggests no impairment. |
| Clinical Pearls | TRILYTE is a polyethylene glycol (PEG)-based colonoscopy preparation. Administer in divided doses per prescribing information; common regimen: 2 liters evening before and 2 liters morning of procedure. Ensure adequate hydration to minimize risk of electrolyte disturbances. Contraindicated in patients with ileus, gastrointestinal obstruction, gastric retention, bowel perforation, toxic colitis, or megacolon. Caution in patients with impaired gag reflex, aspiration risk, or renal impairment. Monitor for nausea, bloating, and abdominal cramps; slow administration or temporary cessation may alleviate symptoms. |
| Patient Advice | Take TRILYTE exactly as prescribed; do not skip doses. Split-dose regimen improves cleansing efficacy. · Stay near a bathroom after starting preparation; expect frequent watery stools. · Do not eat solid food from start of preparation until after procedure; only clear liquids allowed. · Drink additional clear liquids before, during, and after preparation to prevent dehydration. · Contact your doctor if you experience severe vomiting, abdominal distension, or bleeding. · Taste may be improved by chilling the solution; do not add any flavorings or sweeteners. |