Skip to main content

Generlac

Generic: Lactulose

Verified·Apr 23, 2026
Manufacturer
Morton Grove
NDC
62135-892
RxCUI
391937
Route
ORAL
ICD-10 indication
K72.90

Affordability Check

How much will you actually pay for Generlac?

In 30 seconds, see every legitimate way to afford Generlac — Medicare copay, manufacturer copay card, Patient Assistance Program, grants, or cash.

Check my options →

About Generlac

What is this medication? Generlac is a prescription liquid medication, chemically known as lactulose, that is primarily used to treat or prevent a brain condition called portal-systemic encephalopathy. This condition is a complication of severe liver disease where the liver cannot properly filter certain toxins from the blood. Generlac works by lowering the amount of ammonia in the bloodstream, which helps to improve mental status and neurological function in patients with significant liver damage.

In addition to its use for liver-related issues, Generlac is also frequently prescribed as a laxative to treat chronic constipation. It is categorized as an osmotic laxative, meaning it works by drawing water into the colon from surrounding body tissues. This process softens the stool and increases the frequency of bowel movements, making it easier for the patient to pass waste while helping the body eliminate excess ammonia through the digestive tract.

Copay & patient assistance

Detailed copay and financial assistance information is not publicly available for this medication at this time. Please consult your pharmacist or the manufacturer's official patient support program for more details.

External links go directly to the manufacturer's portal. RxCopays does not receive compensation for referrals.

Compare pricing elsewhere

RxCopays doesn't sell drugs or take referral fees. Here are the transparent-pricing directories we recommend checking alongside your insurance formulary.

We deep-link because transparency helps patients. None of these partners pay RxCopays.

Prescribing information

From the FDA-approved label for Generlac. Official source: DailyMed (NLM) · Label effective Jul 16, 2024

Indications and usage
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
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
CONTRAINDICATIONS Since Generlac Solution (Lactulose Solution, USP) contains galactose (less than 1.6 g/15 mL), it is contraindicated in patients who require a low galactose diet.
Warnings
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.
Adverse reactions
ADVERSE REACTIONS Precise frequency data are not available. Generlac Solution 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 Chartwell RX, LLC at 1-845-232-1683 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Label text is reproduced as-is from the FDA-approved label. We do not paraphrase, summarize, or omit. Content above is for informational purposes only and is not medical advice. Always consult your prescribing clinician or pharmacist before making decisions about your medication.

Conditions we've indexed resources for

Click a condition to see copay cards, grants, and PA rules specific to it. For the full list of FDA-approved indications, see Prescribing information above.

Medicare Part D coverage

How Generlac appears across Medicare Part D plan formularies nationally. Source: CMS monthly Prescription Drug Plan file (2026-04-30).

Covered by plans

62%

3,408 of 5,509 plans

Most common tier

Tier 2

On 68% of covering formularies

Prior authorization required

0%

of covering formularies

TierFormularies on this tierShare
Tier 1 (preferred generic)91
28%
Tier 2 (generic)219
68%
Tier 3 (preferred brand)11
3%
Tier 4 (non-preferred brand)2
1%

Step therapy: 0% of formularies

Quantity limits: 0% of formularies

Coverage breadth: 323 of 65 formularies

How to read this:plans on the same formulary share tier + PA rules. Your specific plan's copay depends on (a) the tier above, (b) your plan's cost-share for that tier, (c) whether you're in the initial coverage phase or past the 2026 $2,000 out-of-pocket cap. For your exact plan, check its Summary of Benefits or log in to your Medicare.gov account. Copay cards don't apply to Medicare (federal law).

Prior authorization & coverage

PayerPAStep therapyCopay tier

Medicare Part D

Related drugs

How this page is sourced

  • Drug identity verified against openFDA NDC Directory.
  • Label text (when shown) originates from NLM DailyMed.
  • Copay and assistance URLs verified periodically; if you hit a broken link, tell us.