Rudolac

Lactulose

Method of action: Detoxifying, Hypoazotemic, Laxative, Ph-Lowering Of Intestinal Contents, Stimulating Peristalsis Of The Intestine

Treatment option: Constipation

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Rudolac

Rudolac: Identity, Composition, and Form

Rudolac is a pharmaceutical preparation whose active ingredient is Lactulose (INN), typically supplied as an oral solution or syrup. This medicine is defined as a single-entity product based on a synthetic disaccharide, a type of sugar that the body does not easily absorb.

Lactulose is chemically synthesized from the simple sugars galactose and fructose. Because the human small intestine lacks the necessary enzymes, this compound remains virtually unchanged as it passes through, ensuring its therapeutic action is localized to the lower gastrointestinal tract. The non-absorbable nature of Lactulose allows the concentration of the effect where needed, which minimizes systemic exposure.

What Pharmacological Class Does Rudolac Belong To?

Rudolac belongs to the pharmacological class of osmotic laxatives, agents that help regulate bowel function by drawing water into the colon. It is classified as an hyperosmotic agent because its primary mechanism relies on creating an osmotic gradient.

Once the non-absorbed Lactulose reaches the colon, it exerts an osmotic effect, pulling surrounding body water into the large intestine. This process softens the stool and increases its volume. The fermentation of the compound by colonic microbiota generates organic acids that function as an osmotic laxative. The general purpose of this action is to promote regular, easier bowel movements for the relief of constipation. As its effect is limited to the colon, it is regarded as a predictable and reliable non-systemic laxative.

What side effects are possible with Rudolac?

Possible Side Effects and Safety Information

Rudolac, which contains the active ingredient Lactulose, has a safety profile primarily linked to its non-systemic action in the lower gastrointestinal tract. The officially documented adverse reactions are categorized by frequency, based on clinical data and post-marketing surveillance.

Frequency Classification	Documented Adverse Reactions (System-Organ Class)
Very Common (≥ 1/10)	Diarrhoea (Gastrointestinal disorders)
Common (≥ 1/100 to < 1/10)	Flatulence, Abdominal pain, Nausea, Vomiting (Gastrointestinal disorders)
Uncommon	Electrolyte Imbalance (Investigations)
Not Known	Hypersensitivity reactions (Immune system disorders); Rash, Pruritus, Urticaria (Skin disorders)

Time- and Dose-Related Safety Patterns

Flatulence and intestinal cramps are often experienced during the initial days of treatment but are typically transient. Conversely, prolonged use of excessive or unadjusted doses is associated with the risk of persistent diarrhea, which can lead to a serious disturbance of the body’s electrolyte balance, specifically hypokalemia (low potassium).

Population-Specific Safety Considerations

Official labeling requires specific caution or monitoring for certain groups. For older adults or debilitated patients receiving the medicine for more than six months, periodic control of serum electrolytes is necessary. Infants and small children should only use laxatives exceptionally and under medical supervision. Caution is also noted for diabetic patients due to the presence of minor residual sugars (galactose, lactose, fructose) from the synthesis process.

Safety Restrictions

The medicine is formally contraindicated in patients with conditions such as galactosaemia, gastrointestinal obstruction, acute inflammatory bowel disease, or a risk of digestive perforation. The safety profile also highlights a high-level concern regarding the potential for increased potassium loss when Rudolac is used concomitantly with certain other medications.

Overdose and Emergency Response

Overdose and When to Seek Help

The information below summarizes the officially documented descriptions of overdose for Rudolac (Lactulose) as found in government regulatory prescribing information.

Documented Overdose Manifestations and Risks

The primary clinical signs expected from overdosage are diarrhea and abdominal cramps. Associated symptoms reported in regulatory documentation include nausea and vomiting. These manifestations signal that an excessive dose has been taken and the medication should be terminated.

The core risk of overdosage is the resulting effect on fluid balance and electrolytes. Severe, prolonged diarrhea can lead to significant fluid loss and electrolyte depletion, specifically hypokalemia (low potassium) and hypernatremia (high sodium).

Required Emergency Actions

The official guidance on managing an overdosage focuses on two mandatory actions:

Termination of the medication: The drug must be stopped immediately upon recognizing signs of overdosage, such as unusual or persistent diarrhea.
Supportive Treatment: Treatment consists of fluid and electrolyte replacement to correct the imbalances and dehydration caused by the excessive diarrhea.

Regulators advise contacting a physician or healthcare provider if an unusual diarrheal condition occurs. No specific antidote is documented in the official labeling for Lactulose overdose. A specific population consideration notes that infants are vulnerable to developing dehydration and hyponatremia from overdosage.

Therapeutic Uses of Rudolac

What Rudolac treats: main uses and benefits

This medicine is commonly used across two primary therapeutic domains: managing bowel function and supporting neurological stability in severe liver disease.

The medicine is commonly used for managing chronic constipation and intermittent episodic difficulties in defecation. It addresses symptoms related to physical discomfort and noticeable physiological strain involving straining, infrequent passage, and hard, dry stools. This includes use in postoperative patients or individuals with conditions like anal fissures, where the act of straining must be avoided. Furthermore, it is applied within the therapeutic domain of Hepatic Encephalopathy (HE), relevant for managing symptoms of increased neurological or muscular activity.

The primary purpose is to help ease the symptomatic burden and assist with maintaining functional stability. This use supports the management of the patient's mental status and contributes to improved day-to-day comfort during symptomatic periods.

Quick Fact: Relief for Straining This agent is commonly used to help with symptoms related to physical discomfort during bowel movements, supporting relief from straining.

Regulatory References

Lactulose: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Eligibility for Rudolac Use: Official Regulatory Information

Rudolac (Lactulose) use is defined by official regulatory labeling across specific patient populations. The medicine is primarily permitted for use in adults for both approved indications.

Absolute Contraindications

Use is strictly prohibited (contraindicated) in patients with a history of Galactosemia or those who must follow a low galactose diet, as trace amounts of sugars related to Lactulose exist in the solution. It is also contraindicated in individuals with known or suspected gastrointestinal obstruction or digestive perforation, as defined by regulatory authorities.

Restricted and Conditional Use

Patients with Diabetes Mellitus should use the medicine with caution, due to the presence of small amounts of unabsorbed sugars. While no specific dosage adjustments are required for those with renal or hepatic impairment, the use of laxatives in children is often not recommended or is restricted, and requires medical supervision. US labeling states that safety and effectiveness in the general pediatric population for constipation have not been established.

Pregnancy and Lactation

The medicine is generally considered permitted for use during pregnancy and lactation, though regulatory caution is advised.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official interaction profile for Rudolac (Lactulose) is defined by its non-systemic effect on the large intestine, primarily leading to pharmacodynamic or electrolyte-related interaction patterns rather than common metabolic interactions.

Documented Interaction Categories

Category	Documented Interaction Pattern
Colonic pH Interactions	Co-administration with non-absorbable antacids may inhibit the desired reduction in colonic pH, potentially resulting in a lack of the medicine's primary effect. The use of certain pH-dependent released drugs may also be affected by the lowered colonic pH.
Electrolyte-Loss Interactions	High-dose or prolonged use may lead to excessive diarrhea, carrying a theoretical risk of increased potassium loss. This necessitates caution when used with potassium-losing drugs, such as thiazides, corticosteroids, or Amphotericin B.
Secondary Effects	Potassium loss can increase the effect of cardiac glycosides (e.g., Digoxin) if a state of hypokalemia is induced.
Microbial Interference	The breakdown of Lactulose requires colonic bacteria, which may be disrupted by co-administration with certain anti-infective agents (e.g., Neomycin).

Procedural and Population Constraints

The medicine is contraindicated in patients on a low galactose diet. A procedural restriction exists for patients undergoing electrocautery (such as proctoscopy or colonoscopy) due to the theoretical hazard of an explosive reaction caused by the hydrogen gas produced by Lactulose fermentation; in this context, bowel cleansing must be performed using a non-fermentable solution.

Mechanism of Action

Rudolac's active ingredient, Lactulose, is a non-digestible disaccharide that bypasses human enzymes. Its mechanism is initiated by serving as a substrate for saccharolytic bacteria in the colon, primarily Bifidobacterium and Lactobacillus species. These bacteria ferment Lactulose to produce short-chain organic acids, including lactic and acetic acid.

This fermentation leads to a dual physiological cascade. First, the accumulation of unabsorbed Lactulose and its acidic byproducts increases the osmotic pressure within the large intestine. This osmotic gradient draws water from the surrounding tissues into the colon lumen. This physical process increases the volume and softens the consistency of the intestinal contents, which mechanically stimulates the smooth muscle walls, increasing smooth muscle contraction (peristalsis) and resulting in increased transit of colonic contents.

Second, the resulting organic acids lower the colonic pH. This acidic environment is the necessary condition for influencing nitrogenous waste by driving the chemical conversion of absorbable ammonia ( NH3) into the non-absorbable ammonium ion ( NH4^+). By trapping NH3 in this ionized form, the mechanism limits its reabsorption across the colonic mucosa, resulting in the excretion of nitrogen waste via the feces.

Dosage and Administration Information

How to Use Rudolac: Official Administration Guidelines

Rudolac (Lactulose) is administered according to specific, documented instructions that detail the route, dose, and frequency based on the condition being addressed. The medicine is primarily used as an oral solution or syrup. However, the rectal route is also an approved option, typically reserved for the management of acute or severe cases of hepatic encephalopathy (HE) when oral intake is compromised.

Official Dosing and Frequency

Administration is structured around two distinct goals, which govern the required dosage and schedule:

Condition	Standard Adult Dosing (Oral)	Frequency / Titration Logic
Chronic Constipation	Starts at 15 mL to 30 mL (10 g to 20 g); maximum daily dose up to 60 mL (40 g)	Typically administered once daily.
Hepatic Encephalopathy (HE)	Initial dose of 30 mL to 45 mL (20 g to 30 g)	Given in multiple divided doses (e.g., every 6 to 8 hours), with the dose titrated to achieve a target of two to three soft stools per day.

Administration Context and Special Conditions

For oral intake, the solution may be consumed undiluted or mixed with liquids such as water or fruit juice for palatability. A single daily dose is commonly advised to be taken at the same time each day. The full dose should be swallowed promptly and not held in the mouth. In the case of rectal administration for HE, the enema must be prepared by mixing 300 mL of the solution with 700 mL of water or saline and must be retained for 30 to 60 minutes. Therapy can range from short-term use for acute episodes to continuous long-term management.

Pediatric patients require specific weight- or age-based dosing as detailed in the official prescribing information.

Recent Clinical Evidence

Research evidence / Overview of Studies for Rudolac

The research base for Rudolac (Lactulose) consists of studies that explore the relationship between its use and certain outcomes in patients with specific digestive and liver conditions. This evidence includes Randomized Controlled Trials (RCTs)—a research design relevant for exploring effects—along with systematic reviews that combine the findings of multiple trials. This summary describes what the research has monitored and what is known so far, without offering any clinical advice.

Evidence for Use in Chronic Constipation

Research examined the use of Rudolac primarily through short-term RCTs and meta-analyses involving adult participants. These studies were used in research exploring how symptoms change over time, focusing on outcomes related to physical discomfort. Studies reported measurements of statistically higher weekly bowel movement frequency observed in the groups receiving Rudolac compared to placebo groups. Research measured changes during the study period that related to stool consistency and reported observations of softer stool consistency. However, the available data mainly represent results from short-term follow-up durations. Evidence is limited regarding consistency over years of use.

Evidence for Use in Hepatic Encephalopathy (HE)

Rudolac was evaluated in settings involving conditions associated with acute or disruptive episodes, specifically Hepatic Encephalopathy (HE). Studies monitored outcomes related to systemic or functional imbalance by measuring ammonia levels in the blood and research examined changes in neurological state. Findings describe patterns observed in the studies where ammonia levels changed and where changes in neurological function assessments were reported. Preventative studies research describes patterns where the agent was observed to be associated with a lower rate of relapse compared to control groups in this condition. Certainty remains low for long-term outcomes such as overall survival.

Research on Adjunctive Use for Stool Softening

The available evidence for using Rudolac as a stool softener to avoid physiological strain or stress was studied for its impact on patient-reported outcomes describing perceived discomfort. Studies monitored outcomes related to consistency measurements, consistent with findings from the general constipation studies. However, evidence is limited and is often related to the findings of the primary constipation indication.

Long-Term Studies and Follow-Up

The research exploring long-term effects are not fully established for most uses. The evidence for managing chronic constipation over extended periods is less characterized by large-scale, dedicated RCTs. The research provides context but does not determine whether an individual will respond similarly over several years.

Evidence in Special Populations

Studies research examined Rudolac in older adult populations, and pediatric patients were observed in this population for many years, although evidence is limited to fewer dedicated trials. Data for certain groups remain insufficient. Findings describe group patterns, not personal outcomes, and results may apply only to the populations studied.

Key Studies & References

Frequently Asked Questions (FAQ)

Common questions about Rudolac (FAQ)

Q: What is the generic name of the drug Rudolac?

The active ingredient in Rudolac is Lactulose, which is the internationally recognized generic name for the medicine. According to official product descriptions, Lactulose is a synthetic disaccharide, which is a type of sugar the body cannot easily absorb.

Q: What happens if I forget a dose of Rudolac?

If a dose is missed, official regulatory documents state to skip the missed dose. The advice is to take the next dose at the usual scheduled time and to avoid taking a double dose to make up for the one that was missed.

Q: What should I do if I accidentally take too much Rudolac (overdose)?

In the event of an overdosage, the expected major symptoms are abdominal cramps and diarrhea, as indicated in the official product information. Official labels state that the medication may need to be terminated. If symptoms like diarrhea are severe or do not resolve, it may be necessary to contact a healthcare professional.

Q: What is the difference in dosing for the syrup versus the solution?

Official regulatory documents typically refer to the product as either 'Lactulose solution' or 'Lactulose syrup' interchangeably. Since both forms are liquids and the dosing is determined by volume in milliliters (mL), there does not appear to be an official dosing distinction cited between the names 'solution' and 'syrup.'

Q: Should I take Rudolac with food or on an empty stomach?

Official product information indicates the medicine can be taken with or without food. Regulatory sources also note that some patients find it more palatable when it is mixed with liquids, such as water, milk, or fruit juice.

Q: Can I drive or operate machinery after taking this medicine?

Official regulatory documents state that this medicine has no or a negligible influence on the ability to drive or use machines. The drug's action is primarily limited to the digestive system.

Q: How should I dispose of Rudolac that has been frozen?

Official guidance warns that the solution should not be frozen, as this may cause it to become a thick semi-solid. While there is no specific disposal instruction for a frozen product, its normal viscosity should return if it is warmed back up to room temperature. Disposal of any unused or expired medicine is advised to be carried out according to local pharmaceutical waste requirements.

Q: How quickly does the medicine start working for constipation?

Since the medicine must reach the colon to begin its therapeutic effect, official product information indicates that 24 to 48 hours may be required to produce a normal bowel movement. This time frame allows for the drug's osmotic and fermentative actions to take place.

How should Rudolac be stored and disposed of?

Rudolac (Lactulose solution) must be stored at Controlled Room Temperature, specifically between 20 C to 25 C (68 F to 77 F), as defined by official regulatory labeling.

Storage Requirements

Temperature Restrictions: The solution must not be frozen and must avoid prolonged exposure to temperatures above 30 C (86 F). Freezing may cause the solution to become a viscous semi-solid.
Environmental Protection: Keep the container tightly closed and store in a light-resistant container, protected from direct light. Exposure to excessive heat or light may cause extreme darkening and turbidity, which indicates the product must not be used.
Safety: The medicine must be kept out of the reach of children.