U.S. Brand Names:

Constulose®; Enulose®; Generlac; Kristalose™

Generic Available:

Yes

Canadian Brand Names:

Acilac; Apo-Lactulose®; Laxilose; PMS-Lactulose

Use:

Adjunct in the prevention and treatment of portal-systemic encephalopathy; treatment of chronic constipation

Pregnancy Risk Factor:

B

Lactation:

Excretion in breast milk unknown

Contraindications:

Hypersensitivity to lactulose or any component of the formulation; galactosemia (or patients requiring a low galactose diet)

Warnings/Precautions:

Use with caution in patients with diabetes mellitus; monitor periodically for electrolyte imbalance when lactulose is used >6 months or in patients predisposed to electrolyte abnormalities (eg, elderly); patients receiving lactulose and an oral anti-infective agent should be monitored for possible inadequate response to lactulose

Adverse Reactions:

Frequency not defined: Gastrointestinal: Flatulence, diarrhea (excessive dose), abdominal discomfort, nausea, vomiting, cramping

Overdosage/Toxicology:

Symptoms of overdose include diarrhea, abdominal pain, hypochloremic alkalosis, dehydration, hypotension, and hypokalemia. Treatment includes supportive care.

Drug Interactions:

Decreased effect: Oral neomycin, laxatives, antacids

Stability:

Keep solution at room temperature to reduce viscosity; discard solution if cloudy or very dark

Mechanism of Action:

The bacterial degradation of lactulose resulting in an acidic pH inhibits the diffusion of NH3 into the blood by causing the conversion of NH3 to NH4+; also enhances the diffusion of NH3 from the blood into the gut where conversion to NH4+ occurs; produces an osmotic effect in the colon with resultant distention promoting peristalsis

Dosage:

Diarrhea may indicate overdosage and responds to dose reduction

Prevention of portal systemic encephalopathy (PSE): Oral:

Infants: 2.5-10 mL/day divided 3-4 times/day; adjust dosage to produce 2-3 stools/day

Older Children: Daily dose of 40-90 mL divided 3-4 times/day; if initial dose causes diarrhea, then reduce it immediately; adjust dosage to produce 2-3 stools/day

Constipation: Oral:

Children: 5 g/day (7.5 mL) after breakfast

Adults: 15-30 mL/day increased to 60 mL/day in 1-2 divided doses if necessary

Acute PSE: Adults:

Oral: 20-30 g (30-45 mL) every 1-2 hours to induce rapid laxation; adjust dosage daily to produce 2-3 soft stools; doses of 30-45 mL may be given hourly to cause rapid laxation, then reduce to recommended dose; usual daily dose: 60-100 g (90-150 mL) daily

Rectal administration: 200 g (300 mL) diluted with 700 mL of H20 or NS; administer rectally via rectal balloon catheter and retain 30-60 minutes every 4-6 hours

Administration:

Dilute lactulose in water, usually 60-120 mL, prior to administering through a gastric or feeding tube. Syrup formulation has been used in preparation of rectal solution.

Monitoring Parameters:

Blood pressure, standing/supine; serum potassium, bowel movement patterns, fluid status, serum ammonia

Dietary Considerations:

Contraindicated in patients on galactose-restricted diet; may be mixed with fruit juice, milk, water, or citrus-flavored carbonated beverages.

Patient Education:

Not for long-term use. Take as directed, alone, or diluted with water, juice or milk, or take with food. Laxative results may not occur for 24-48 hours; do not take more often than recommended or for a longer time than recommended. Do not use any other laxatives while taking lactulose. Increased fiber, fluids, and exercise may also help reduce constipation. Do not use if experiencing abdominal pain, nausea, or vomiting. Diarrhea may indicate overdose. May cause flatulence, belching, or abdominal cramping. Report persistent or severe diarrhea or abdominal cramping. Breast-feeding precaution: Consult prescriber if breast-feeding.

Dental Health: Effects on Dental Treatment:

No significant effects or complications reported

Dental Health: Vasoconstrictor/Local Anesthetic Precautions:

No information available to require special precautions

Mental Health: Effects on Mental Status:

None reported

Mental Health: Effects on Psychiatric Treatment:

None reported

International Brand Names:

Acilac (CA); Adco-Liquilax® (ZA); Apo-Lactulose® (CA); Avolac® (BD); Belmalax® (ES); Bifinorma® (DE); Bifiteral® (AT, BE, DE, LU); Biolac® (IT); Certalac® (BE); Colsanac® (PT); Dhactulose® (SG); Dia-Colon® (IT); Dismam® (CL); Dulax® (IE); Dulcolactol® (ID); Duphalac® (AT, AU, BE, BG, CH, CL, CZ, EC, ES, FI, FR, GB, HK, HR, HU, ID, IE, IT, LU, NL, NO, PL, PT, RO, RU, SE, SG, TH, TR, ZA); Epalat® (IT); Epalfen® (IT); Eugalac® (DE); Farlac® (BR); Gatinar® (CH); Genocolan® (AR); Gerelax® (IE, IL); Hepalac® (TH); Hepaticum Lac Medice® (DE); Kattwilact® (DE); Lac-Dol® (AU); Laclose® (BD); Lacson Syrup® (ZA); Lactocur® (DE, LU); Lactuflor® (DE); Lactugal® (GB); Lactulac® (DO); Lactulax® (EC, HN, ID, IL, MX, PA, SV); Lactulen® (CO); Lactulol® (PL); Lactulon® (AR); Lactulosa® (CL); Lactulosa Llorente® (ES); Lactulose 1A Pharma® (DE); Lactulose AL® (DE, RO); Lactulose Arcana® (AT); Lactulose AZU® (DE); Lactulose® (BD, GB, RO, RU); Lactulose Biphar® (FR); Lactulose EG® (BE); Lactulose Genericon® (AT); Lactulose Heumann® (DE); Lactulose Hexal® (DE); Lactulose Medic® (DK); Lactulose-MIP® (PL); Lactulose Neda® (DE); Lactulose-ratiopharm® (DE, LU); Lactulose-saar® (DE); Lactulose Sandoz® (DE); Lactulose Stada® (DE); Lactulosum Enila® (BR); Lactulosum® (PL); Lactuphar® (BE); Lactuverlan® (DE); Laevilac® (DE); Laevolac® (AT, IL, IT, NZ, PT, RO, TR, ZA); Laevolac-Lactulose® (AT); Laevolac LaktulÓ[z® (HU); Laktipex® (SE); Laktulose Danipharm® (DK); Laktulose Medic® (DK); Laktulose® (NO); Laktulose PS® (DK); Laktulose SAD® (DK); Laktulos Pharmacia® (SE); Lansoyl Lactulose® (BE); Lassifar® (IT); Lattulosio Dorom® (IT); Lattulosio GNR® (IT); Lattulosio IBI® (IT); Lattulosio® (IT); Lattulosio Pliva® (IT); Lattulosio-ratiopharm® (IT); Lattulosio Teva® (IT); Laxette Solution® (ZA); Laxilose (CA); Laximed® (DE); Laxodad® (LB, RO); Laxose® (IE); Legendal® (CH, NL); Levolac® (FI, NO); Lisalac® (RU); Lis EPS® (IT); Lis® (IT); Livo Luk® (IN); Livoton® (BD); Loraga® (FI, SE); Medilax® (DK); Medilet® (DE); Monilac® (JP); Normalac® (PL, TR); Normase® (IT, PL, RU); Osmolac® (IT); Osmolak® (TR); Pacific Lactulose® (NZ); Perilac® (TR); PMS-Lactulose (CA, SG); Portalak® (HR, RU, SI, YU); Pralax® (ID); Prorektal® (SI); Regulact® (MX); Regulose® (BD, GB); Rencef® (CL); Rudolac® (CH); Sanilak® (YU); Senokot® (ZA); Serelose® (BD); Sintolatt® (IT); Tenualax® (AR); Tulotract® (DE); Verelait® (IT)