LACTULOSE: 3,983 Adverse Event Reports & Safety Profile

DESCRIPTION Lactulose is a synthetic disaccharide in solution form for oral administration.

Each

15 mL of Lactulose Solution contains: 10 g lactulose (and less than 1.6 g galactose, less than 1.2 g lactose, and 1.2 g or less of other sugars). Also contains FD&C Blue No. 1, FD&C Yellow No. 6, purified water, and flavoring. Sodium hydroxide used to adjust pH. The pH range is 2.5 to 6.5. Lactulose is a colonic acidifier which promotes laxation. The chemical name for lactulose is 4-0-ß-D-galactopyranosyl-D-fructofuranose. The molecular formula is C 12 H 22 O 11 . It has the following structural formula: The molecular weight is 342.30. It is freely soluble in water.

Chemical

Structure

INDICATIONS AND USAGE For the prevention and treatment of portal-systemic encephalopathy, including the stages of hepatic pre-coma and coma. Controlled studies have shown that lactulose solution therapy reduces the blood ammonia levels by 25 to 50%; this is generally paralleled by an improvement in the patients' mental state and by an improvement in EEG patterns. The clinical response has been observed in about 75% of patients, which is at least as satisfactory as that resulting from neomycin therapy. An increase in patients' protein tolerance is also frequently observed with lactulose solution therapy. In the treatment of chronic portal-systemic encephalopathy, lactulose solution has been given for over 2 years in controlled studies.

DOSAGE AND ADMINISTRATION Oral Adult The usual adult oral dosage is 2 to 3 tablespoonfuls (30 to 45 mL, containing 20 g to 30 g of Generlac Solution) three or four times daily. The dosage may be adjusted every day or two to produce 2 or 3 soft stools daily. Hourly doses of 30 to 45 mL of Generlac Solution may be used to induce the rapid laxation indicated in the initial phase of the therapy of portal-systemic encephalopathy. When the laxative effect has been achieved, the dose of Generlac Solution may then be reduced to the recommended daily dose. Improvement in the patient's condition may occur within 24 hours but may not begin before 48 hours or even later. Continuous long-term therapy is indicated to lessen the severity and prevent the recurrence of portal-systemic encephalopathy. The dose of Generlac Solution for this purpose is the same as the recommended daily dose.

Pediatric

Very little information on the use of lactulose in young children and adolescents has been recorded. As with adults, the subjective goal in proper treatment is to produce 2 to 3 soft stools daily. On the basis of information available, the recommended initial daily oral dose in infants is 2.5 to 10 mL in divided doses. For older children and adolescents, the total daily dose is 40 to 90 mL. If the initial dose causes diarrhea, the dose should be reduced immediately. If diarrhea persists, Generlac Solution should be discontinued.

Rectal

When the adult patient is in the impending coma or coma stage of portal-systemic encephalopathy and the danger of aspiration exists, or when the necessary endoscopic or intubation procedures physically interfere with the administration of the recommended oral doses, Generlac Solution may be given as a retention enema via a rectal balloon catheter. Cleansing enemas containing soapsuds or other alkaline agents should not be used. Three hundred mL of Generlac Solution should be mixed with 700 mL of water or physiologic saline and retained for 30 to 60 minutes.

Generlac

Solution enema may be repeated every 4 to 6 hours. If the enema is inadvertently evacuated too promptly, it may be repeated immediately. The goal of treatment is reversal of the coma stage in order that the patient may be able to take oral medication. Reversal of coma may take place within 2 hours of the first enema in some patients.

Generlac

Solution, given orally in the recommended doses, should be started before Generlac Solution by enema is stopped entirely.

CONTRAINDICATIONS Since KRISTALOSE ® (LACTULOSE)

For Oral

Solution contains galactose (less than 0.3 g/10 g as a total sum with lactose), it is contraindicated in patients who require a low galactose diet.

ADVERSE REACTIONS Precise frequency data are not available. Lactulose may produce gaseous distention with flatulence or belching and abdominal discomfort such as cramping in about 20% of patients. Excessive dosage can lead to diarrhea with potential complications such as loss of fluids, hypokalemia, and hypernatremia. Nausea and vomiting have been reported. To report SUSPECTED ADVERSE REACTIONS, contact Apozeal Pharmaceuticals Inc. at 1-833-688-7848 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

WARNINGS A theoretical hazard may exist for patients being treated with lactulose solution who may be required to undergo electrocautery procedures during proctoscopy or colonoscopy. Accumulation of H 2 gas in significant concentration in the presence of an electrical spark may result in an explosive reaction. Although this complication has not been reported with lactulose, patients on lactulose therapy undergoing such procedures should have a thorough bowel cleansing with a non-fermentable solution. Insufflation of CO 2 as an additional safeguard may be pursued but is considered to be a redundant measure.

PRECAUTIONS General Since Generlac Solution contains galactose (less than 1.6 g/15 mL) and lactose (less than 1.2 g/15 mL), it should be used with caution in diabetics. In the overall management of portal-systemic encephalopathy, it should be recognized that there is serious underlying liver disease with complications such as electrolyte disturbance (e.g., hypokalemia) for which other specific therapy may be required. Infants receiving lactulose may develop hyponatremia and dehydration.

Drug Interactions

There have been conflicting reports about the concomitant use of neomycin and lactulose solution. Theoretically, the elimination of certain colonic bacteria by neomycin and possibly other anti-infective agents may interfere with the desired degradation of lactulose and thus prevent the acidification of colonic contents. Thus the status of the lactulose-treated patient should be closely monitored in the event of concomitant oral anti-infective therapy. Results of preliminary studies in humans and rats suggest that nonabsorbable antacids given concurrently with lactulose may inhibit the desired lactulose-induced drop in colonic pH. Therefore, a possible lack of desired effect of treatment should be taken into consideration before such drugs are given concomitantly with Generlac Solution. Other laxatives should not be used, especially during the initial phase of therapy for portalsystemic encephalopathy, because the loose stools resulting from their use may falsely suggest that adequate Generlac Solution dosage has been achieved. Carcinogenesis, Mutagenesis, Impairment of Fertility There are no known human data on long-term potential for carcinogenicity, mutagenicity, or impairment of fertility. There are no known animal data on long-term potential for mutagenicity. Administration of lactulose solution in the diet of mice for 18 months in concentrations of 3 and 10 percent (v/w) did not produce any evidence of carcinogenicity. In studies of mice, rats, and rabbits, doses of lactulose solution up to 6 or 12 mL/kg/day produced no deleterious effects in breeding, conception, or parturition.

Pregnancy Teratogenic Effects Pregnancy

Category B Reproduction studies have been performed in mice, rats, and rabbits at doses up to 2 or 4 times the usual human oral dose and have revealed no evidence of impaired fertility or harm to the fetus due to lactulose. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Nursing

Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Generlac Solution is administered to a nursing woman.

Pediatric Use

Very little information on the use of lactulose in pediatric patients has been recorded (see DOSAGE AND ADMINISTRATION ).

INTERACTIONS There have been conflicting reports about the concomitant use of neomycin and lactulose solution. Theoretically, the elimination of certain colonic bacteria by neomycin and possibly other anti-infective agents may interfere with the desired degradation of lactulose and thus prevent the acidification of colonic contents. Thus the status of the lactulose-treated patient should be closely monitored in the event of concomitant oral anti-infective therapy. Results of preliminary studies in humans and rats suggest that nonabsorbable antacids given concurrently with lactulose may inhibit the desired lactulose-induced drop in colonic pH. Therefore, a possible lack of desired effect of treatment should be taken into consideration before such drugs are given concomitantly with lactulose. Other laxatives should not be used, especially during the initial phase of therapy for portal-systemic encephalopathy, because the loose stools resulting from their use may falsely suggest that adequate lactulose dosage has been achieved.